Heteronuclear Recoupling in Solid-State Magic-Angle-Spinning NMR via Overtone Irradiation
Frydman, Lucio
Heteronuclear Recoupling in Solid-State Magic-Angle-Spinning NMR via Overtone Irradiation Sungsool undergoing magic-angle- spinning (MAS) is introduced, based on the overtone irradiation of one of the coupled nuclei. It is shown that when I is a quadrupole, for instance 14N, irradiating this spin at a multiple
High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning
Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander
2005-01-27
High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.
Devices and process for high-pressure magic angle spinning nuclear magnetic resonance
Hoyt, David W; Sears, Jr., Jesse A; Turcu, Romulus V.F.; Rosso, Kevin M; Hu, Jian Zhi
2014-04-08
A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.
Bayro, Marvin J.
We describe magic-angle spinning NMR experiments designed to elucidate the interstrand architecture of amyloid fibrils. Three methods are introduced for this purpose, two being based on the analysis of long-range [superscript ...
Advanced slow-magic angle spinning probe for magnetic resonance imaging and spectroscopy
Wind, Robert A.; Hu, Jian Zhi; Minard, Kevin R.; Rommereim, Donald N.
2006-01-24
The present invention relates to a probe and processes useful for magnetic resonance imaging and spectroscopy instruments. More particularly, the invention relates to a MR probe and processes for obtaining resolution enhancements of fluid objects, including live specimens, using an ultra-slow (magic angle) spinning (MAS) of the specimen combined with a modified phase-corrected magic angle turning (PHORMAT) pulse sequence. Proton NMR spectra were measured of the torso and the top part of the belly of a female BALBc mouse in a 2T field, while spinning the animal at a speed of 1.5 Hz. Results show that even in this relatively low field with PHORMAT, an isotropic spectrum is obtained with line widths that are a factor 4.6 smaller than those obtained in a stationary mouse. Resolution of ^{1}H NMR metabolite spectra are thus significantly enhanced. Results indicate that PHORMAT has the potential to significantly increase the utility of ^{1}H NMR spectroscopy for in vivo biochemical, biomedical and/or medical applications involving large-sized biological objects such as mice, rats and even humans within a hospital setting. For small-sized objects, including biological objects, such as excised tissues, organs, live bacterial cells, and biofilms, use of PASS at a spinning rate of 30 Hz and above is preferred.
Frydman, Lucio
Fast radio-frequency amplitude modulation in multiple-quantum magic-angle-spinning nuclear magnetic of this experiment has been the poor efficiency of the radio-frequency pulses used in converting multiple-modulated radio-frequency pulses, and which can yield substantial signal and even resolution enhancements over
A unified heteronuclear decoupling strategy for magic-angle-spinning solid-state NMR spectroscopy
Equbal, Asif; Bjerring, Morten; Nielsen, Niels Chr. E-mail: ncn@inano.au.dk; Madhu, P. K. E-mail: ncn@inano.au.dk
2015-05-14
A unified strategy of two-pulse based heteronuclear decoupling for solid-state magic-angle spinning nuclear magnetic resonance is presented. The analysis presented here shows that different decoupling sequences like two-pulse phase-modulation (TPPM), X-inverse-X (XiX), and finite pulse refocused continuous wave (rCW{sup A}) are basically specific solutions of a more generalized decoupling scheme which incorporates the concept of time-modulation along with phase-modulation. A plethora of other good decoupling conditions apart from the standard, TPPM, XiX, and rCW{sup A} decoupling conditions are available from the unified decoupling approach. The importance of combined time- and phase-modulation in order to achieve the best decoupling conditions is delineated. The consequences of different indirect dipolar interactions arising from cross terms comprising of heteronuclear and homonuclear dipolar coupling terms and also those between heteronuclear dipolar coupling and chemical-shift anisotropy terms are presented in order to unfold the effects of anisotropic interactions under different decoupling conditions. Extensive numerical simulation results are corroborated with experiments on standard amino acids.
PROOF COPY 003305JCP Second-order quadrupole-shielding effects in magic-angle spinning
Frydman, Lucio
PROOF COPY 003305JCP PROOF COPY 003305JCP Second-order quadrupole-shielding effects in magic interaction can give rise to shielding-derived terms that are not entirely averaged away by conventional magic-order quadrupole effects makes such quadrupole-shielding cross-terms observable. Although this may present
Spinning angle optical calibration apparatus
Beer, Stephen K. (Morgantown, WV); Pratt, II, Harold R. (Morgantown, WV)
1991-01-01
An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.
Proton chemical shift anisotropy measurements of hydrogen-bonded functional groups by fast magic) spectroscopy is one of the most suitable tools for studying hydrogen bonding phenomena. Proton NMR spectroscopy theoretically4 and experimentally5 that the isotropic chemical shifts of hydroxyl or amide protons depend
Lafon, Olivier; Thankamony, Aany S. Lilly; Kokayashi, Takeshi; Carnevale, Diego; Vitzthum, Veronika; Slowing, Igor I.; Kandel, Kapil; Vezin, Herve; Amoureux, Jean-Paul; Bodenhausen, Geoffrey; Pruski, Marek
2012-12-21
We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of 13C and 29Si nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surrounding frozen disordered water. The approach is demonstrated using mesoporous silica nanoparticles (MSN), functionalized with 3-(N-phenylureido)propyl (PUP) groups, filled with the surfactant cetyltrimethylammonium bromide (CTAB). The DNP-enhanced proton magnetization is transported into the mesopores via 1H–1H spin diffusion and transferred to rare spins by cross-polarization, yielding signal enhancements ?on/off of around 8. When the CTAB molecules are extracted, so that the radicals can enter the mesopores, the enhancements increase to ?on/off ? 30 for both nuclei. A quantitative analysis of the signal enhancements in MSN with and without surfactant is based on a one-dimensional proton spin diffusion model. The effect of solvent deuteration is also investigated.
Methods for magnetic resonance analysis using magic angle technique
Hu, Jian Zhi (Richland, WA); Wind, Robert A. (Kennewick, WA); Minard, Kevin R. (Kennewick, WA); Majors, Paul D. (Kennewick, WA)
2011-11-22
Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.
Method for high resolution magnetic resonance analysis using magic angle technique
Wind, Robert A.; Hu, Jian Zhi
2003-11-25
A method of performing a magnetic resonance analysis of a biological object that includes placing the biological object in a main magnetic field and in a radio frequency field, the main magnetic field having a static field direction; rotating the biological object at a rotational frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. According to another embodiment, the radio frequency is pulsed to provide a sequence capable of producing a spectrum that is substantially free of spinning sideband peaks.
Method for high resolution magnetic resonance analysis using magic angle technique
Wind, Robert A.; Hu, Jian Zhi
2004-12-28
A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.
Method for high resolution magnetic resonance analysis using magic angle technique
Wind, Robert A.; Hu, Jian Zhi
2003-12-30
A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.
Bai,M.; Ptitsyn, V.; Roser, T.
2008-10-01
To keep the spin tune in the spin depolarizing resonance free region is required for accelerating polarized protons to high energy. In RHIC, two snakes are located at the opposite side of each accelerator. They are configured to yield a spin tune of 1/2. Two pairs of spin rotators are located at either side of two detectors in each ring in RHIC to provide longitudinal polarization for the experiments. Since the spin rotation from vertical to longitudinal is localized between the two rotators, the spin rotators do not change the spin tune. However, due to the imperfection of the orbits around the snakes and rotators, the spin tune can be shifted. This note presents the impact of the horizontal orbital angle between the two snakes on the spin tune, as well as the effect of the vertical orbital angle between two rotators at either side of the collision point on the spin tune.
Hu, Jian Zhi (Richland, WA); Sears, Jr., Jesse A. (Kennewick, WA); Hoyt, David W. (Richland, WA); Wind, Robert A. (Kennewick, WA)
2009-05-19
Described are a "Discrete Magic Angle Turning" (DMAT) system, devices, and processes that combine advantages of both magic angle turning (MAT) and magic angle hopping (MAH) suitable, e.g., for in situ magnetic resonance spectroscopy and/or imaging. In an exemplary system, device, and process, samples are rotated in a clockwise direction followed by an anticlockwise direction of exactly the same amount. Rotation proceeds through an angle that is typically greater than about 240 degrees but less than or equal to about 360 degrees at constant speed for a time applicable to the evolution dimension. Back and forth rotation can be synchronized and repeated with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. The design permits tubes to be inserted into the sample container without introducing plumbing interferences, further allowing control over such conditions as temperature, pressure, flow conditions, and feed compositions, thus permitting true in-situ investigations to be carried out.
Tao, X. D.; Feng, Z.; Miao, B. F.; Sun, L.; You, B.; Wu, D.; Du, J.; Zhang, W.; Ding, H. F., E-mail: hfding@nju.edu.cn [Department of Physics, National Laboratory of Solid State Microstructures, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)
2014-05-07
We present the experimental study of the spin Hall angle (SHA) and spin diffusion length of Pd with the spin pumping and microwave photoresistance effects. The Py/Pd bilayer stripes are excited with an out-of-plane microwave magnetic field. The pure spin current is thus pumped and transforms into charge current via the inverse spin Hall effect (ISHE) in Pd layer, yielding an ISHE voltage. The ISHE voltage can be distinguished from the unwanted signal caused by the anisotropic magnetoresistance according to their different symmetries. Together with Pd thickness dependent measurements of in and out-of-plane precessing angles and effective spin mixing conductance, the SHA and spin-diffusion length of Pd are quantified as 0.0056?±?0.0007 and 7.3?±?0.7?nm, respectively.
The "magic" angle in the self-assembly of colloids suspended in a nematic host phase
Sergej Schlotthauer; Tillmann Stieger; Michael Melle; Marco G. Mazza; Martin Schoen
2015-05-21
Using extensive Monte Carlo (MC) simulations of colloids immersed in a nematic liquid crystal we compute an effective interaction potential via the local nematic director field and its associated order parameter. The effective potential consists of a local Landau-de Gennes (LdG) and a Frank elastic contribution. Molecular expressions for the LdG expansion coefficients are obtained via classical density functional theory (DFT). The DFT result for the LdG parameter $A$ is improved by locating the phase transition through finite-size scaling theory. We consider effective interactions between a pair of homogeneous colloids with Boojum defect topology. In particular, colloids attract each other if the angle between their center-of-mass distance vector and the far-field nematic director is about $30^{\\circ}$ which settles a long-standing discrepancy between theory and experiment. Using the effective potential in two-dimensional MC simulations we show that self-assembled structures formed by the colloids are in excellent agreement with experimental data.
Eddy, Matthew Thomas
The power of nuclear magnetic resonance spectroscopy derives from its site-specific access to chemical, structural and dynamic information. However, the corresponding multiplicity of interactions can be difficult to tease ...
Bajaj, Vikram S.
Amyloid fibrils are structurally ordered aggregates of proteins whose formation is associated with many neurodegenerative and other diseases. For that reason, their high-resolution structures are of considerable interest ...
Debelouchina, Galia Tzvetanova
?[subscript 2]-Microglobulin (?[subscript 2]m) is the major structural component of amyloid fibrils deposited in a condition known as dialysis-related amyloidosis. Despite numerous studies that have elucidated important ...
Effects of Membrane Peptide Dynamics on High-Resolution Magic-Angle Spinning NMR
. Warschawski, John D. Gross and Robert G. Griffin* Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge MA 02139, USA. D. E. Warschawski, J. D. Gross and R. G. Griffin A (gA), dans une bicouche lipidique hydratée. Les expériences présentées ici constituent la première
"Magic Angle Precession" Bernd Binder
Binder, Bernd
by geometric phases, which are induced by high- speed relativistic rotations and are relevant to propulsion, quark, confinement, heavy nuclei, Sommerfeld, fine structure, propulsion, SO(3), nonlinear, chaotic maps in the vicinity of a magnetic monopole or singularity (Dirac, 1931) that could be located on the tip
Proton Assisted Recoupling at High Spinning Frequencies
Struppe, Jochem
We demonstrate the successful application of [superscript 13]C?[superscript 13]C proton assisted recoupling (PAR) on [U?[superscript 13]C,[superscript 15]N] N-f-MLF-OH and [U?13C,15N] protein GB1 at high magic angle spinning ...
Debelouchina, Galia Tzvetanova
2011-01-01
Amyloid fibrils are insoluble, non-crystalline protein filaments associated with a number of diseases such as Alzheimer's and Type Il diabetes. They can have a functional role in different organisms and many proteins and ...
Andreas, Loren B
2014-01-01
Determination of the 3D structure of membrane proteins is a frontier that is rapidly being explored due to the importance of membrane proteins in regulating cellular processes and because they are the target of many drugs. ...
Dey, Rik Pramanik, Tanmoy; Roy, Anupam; Rai, Amritesh; Guchhait, Samaresh; Sonde, Sushant; Movva, Hema C. P.; Register, Leonard F.; Banerjee, Sanjay K.; Colombo, Luigi
2014-06-02
We have studied angle dependent magnetoresistance of Bi{sub 2}Te{sub 3} thin film with field up to 9?T over 2–20?K temperatures. The perpendicular field magnetoresistance has been explained by the Hikami-Larkin-Nagaoka theory alone in a system with strong spin-orbit coupling, from which we have estimated the mean free path, the phase coherence length, and the spin-orbit relaxation time. We have obtained the out-of-plane spin-orbit relaxation time to be small and the in-plane spin-orbit relaxation time to be comparable to the momentum relaxation time. The estimation of these charge and spin transport parameters are useful for spintronics applications. For parallel field magnetoresistance, we have confirmed the presence of Zeeman effect which is otherwise suppressed in perpendicular field magnetoresistance due to strong spin-orbit coupling. The parallel field data have been explained using both the contributions from the Maekawa-Fukuyama localization theory for non-interacting electrons and Lee-Ramakrishnan theory of electron-electron interactions. The estimated Zeeman g-factor and the strength of Coulomb screening parameter agree well with the theory. Finally, the anisotropy in magnetoresistance with respect to angle has been described by the Hikami-Larkin-Nagaoka theory. This anisotropy can be used in anisotropic magnetic sensor applications.
The G0 Collaboration; D. Androi?; D. S. Armstrong; J. Arvieux; S. L. Bailey; D. H. Beck; E. J. Beise; J. Benesch; F. Benmokhtar; L. Bimbot; J. Birchall; P. Bosted; H. Breuer; C. L. Capuano; Y. -C. Chao; A. Coppens; C. A. Davis; C. Ellis; G. Flores; G. Franklin; C. Furget; D. Gaskell; M. T. W. Gericke; J. Grames; G. Guillard; J. Hansknecht; T. Horn; M. K. Jones; P. M. King; W. Korsch; S. Kox; L. Lee; J. Liu; A. Lung; J. Mammei; J. W. Martin; R. D. McKeown; A. Micherdzinska; M. Mihovilovic; H. Mkrtchyan; M. Muether; S. A. Page; V. Papavassiliou; S. F. Pate; 10 S. K. Phillips; P. Pillot; M. L. Pitt; M. Poelker; B. Quinn; W. D. Ramsay; J. -S. Real; J. Roche; P. Roos; J. Schaub; T. Seva; N. Simicevic; G. R. Smith; D. T. Spayde; M. Stutzman; R. Suleiman; V. Tadevosyan; W. T. H. van Oers; M. Versteegen; E. Voutier; W. Vulcan; S. P. Wells; S. E. Williamson; S. A. Wood; B. Pasquini; M. Vanderhaeghen
2011-06-16
We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory.
Rekveldt, M. Theo; Dijk, Niels H. van; Grigoriev, Serguei V.; Kraan, Wicher H.; Bouwman, Wim G. [Department of Radiation, Radionuclides and Reactors, Faculty of Applied Sciences, Delft University of Technology, 2629 JB Delft (Netherlands); Petersburg Nuclear Physics Institute, 188300 Gatchina, St-Petersburg District (Russian Federation); Department of Radiation, Radionuclides and Reactors, Faculty of Applied Sciences, Delft University of Technology, 2629 JB Delft (Netherlands)
2006-07-15
The recently developed magnetic spin-echo small-angle neutron scattering (SANS) technique provides unique information about the distance correlation of the local vector magnetization as a function of the spin-echo length within a magnetic material. The technique probes the magnetic correlations on a length scale from 10 nm up to 10 {mu}m within the bulk of a magnetic material by evaluating the Larmor precession of a polarized neutron beam in a spin-echo setup. The characteristics of the spin-echo SANS technique are discussed and compared to those of the more conventional neutron depolarization technique. Both of these techniques probe the average size of the magnetic inhomogeneities and the local magnetic texture. The magnetic spin-echo SANS technique gives information on the size distribution of these magnetic inhomogeneities perpendicular to the beam and, in principle, independent on the local magnetic induction. This information is not accessible by the neutron depolarization technique that gives the average size parallel to the beam multiplied with the square of the local magnetic induction. The basic possibilities of the magnetic spin-echo SANS technique are demonstrated by experiments on samples with a strong magnetic texture.
Mathemagician! Mental Math Magic
Engel, Robert
Mathemagician! Mental Math Magic with Arthur Benjamin Organized by the Division of Math & Natural Huenerfauth, Associate Dean of the Division of Math and Natural Sciences: mhuenerfauth
Nuruzzaman, nfn
2014-12-01
The Q-weak experiment in Hall-C at the Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton through the precision measurement of the parity-violating asymmetry in elastic electron-proton scattering at low momentum transfer. There is also a parity conserving Beam Normal Single Spin Asymmetry or transverse asymmetry (B_n) on H_2 with a sin(phi)-like dependence due to two-photon exchange. If the size of elastic B_n is a few ppm, then a few percent residual transverse polarization in the beam, combined with small broken azimuthal symmetries in the detector, would require a few ppb correction to the Q-weak data. As part of a program of B_n background studies, we made the first measurement of B_n in the N-to-Delta(1232) transition using the Q-weak apparatus. The final transverse asymmetry, corrected for backgrounds and beam polarization, was found to be B_n = 42.82 ± 2.45 (stat) ± 16.07 (sys) ppm at beam energy E_beam = 1.155 GeV, scattering angle theta = 8.3 deg, and missing mass W = 1.2 GeV. B_n from electron-nucleon scattering is a unique tool to study the gamma^* Delta Delta form factors, and this measurement will help to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process. To help correct false asymmetries from beam noise, a beam modulation system was implemented to induce small position, angle, and energy changes at the target to characterize detector response to the beam jitter. Two air-core dipoles separated by ~10 m were pulsed at a time to produce position and angle changes at the target, for virtually any tune of the beamline. The beam energy was modulated using an SRF cavity. The hardware and associated control instrumentation will be described in this dissertation. Preliminary detector sensitivities were extracted which helped to reduce the width of the measured asymmetry. The beam modulation system has also proven valuable for tracking changes in the beamline optics, such as dispersion at the target.
V. G. Baryshevsky
2011-01-17
It is shown that in the experiments dedicated for producing of polarized beams of antiprotons during their passage through a polarized gas target placed in a storage ring it is possible to measure not only spin-dependent total cross-sections of antiproton scattering by the proton (deuteron), but also the spin-dependent real part of the coherent zero-angle scattering amplitude in the process of production of a polarized beam of antiprotons.
Hu, Jian Zhi; Kwak, Ja Hun; Yang, Zhenguo; Osborn, William; Markmaitree, Tippawan; Shaw, Leonard D.
2008-07-15
Abstract The significantly enhanced spectral resolution in the 6Li MAS NMR spectra of Li-N-H systems at ultra-high field of 21.1 tesla is exploited, for the first time, to study the detailed electronic and chemical environmental changes associated with mechanical activation of Li-N-H system using high energy balling milling. Complementary to ultra-high field studies, the hydrogen discharge dynamics are investigated using variable temperature in situ 1H MAS NMR at 7.05 tesla field. The significantly enhanced spectral resolution using ultra-high filed of 21.1 tesla was demonstrated along with several major findings related to mechanical activation, including the upfield shift of the resonances in 6Li MAS spectra induced by ball milling, more efficient mechanical activation with ball milling at liquid nitrogen temperature than with ball milling at room temperature, and greatly enhanced hydrogen discharge exhibited by the liquid nitrogen ball milled samples.
Performance of the MAGIC telescopes after the major upgrade
Sitarek, Julian; Colin, Pierre; Mazin, Daniel
2015-01-01
MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located on the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a major upgrade. The main subsystems upgraded were the MAGIC-I camera and its trigger system and the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith angle observations, the standard trigger threshold of the MAGIC telescopes is about 50 GeV. The integral sensitivity for point-like sources with Crab Nebula-like spectra above 220 GeV is (0.66 +/- 0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution, defined as the sigma of a 2-dimensional Gaussian distribution, at energies of a few hundred GeV is below 0.07degree, while the energy resolution is around 16%. We investigate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that th...
V. G. Baryshevsky; A. A. Gurinovich
2005-06-14
In the present paper the equations for the spin evolution of a particle in a storage ring are analyzed considering contributions from the tensor electric and magnetic polarizabilities of the particle. Study of spin rotation and birefringence effect for a particle in a high energy storage ring provides for measurement as the real part of the coherent elastic zero-angle scattering amplitude as well as tensor electric and magnetic polarizabilities. We proposed the method for measurement the real part of the elastic coherent zero-angle scattering amplitude of particles and nuclei in a storage ring by the paramagnetic resonance in the periodical in time nuclear pseudoelectric and pseudomagnetic fields.
Safronova, M S; Safronova, U I; Clark, Charles W
2015-01-01
We predict a sequence of magic-zero wavelengths for the Sr excited $5s5p~ ^3P_0$ state, and provide a general roadmap for extracting transition matrix elements using precise frequency measurements. We demonstrate that such measurements can serve as a best global benchmark of the spectroscopic accuracy that is required for the development of high-precision predictive methods. These magic-zero wavelengths are also needed for state-selective atom manipulation for implementation of quantum logic operations. We also identify five magic wavelengths of the $5s^2\\ ^1S_0 - 5s5p\\ ^3P_0$ Sr clock transition between 350 nm and 500 nm which can also serve as precision benchmarks.
M. S. Safronova; Z. Zuhrianda; U. I. Safronova; Charles W. Clark
2015-07-23
We predict a sequence of magic-zero wavelengths for the Sr excited $5s5p~ ^3P_0$ state, and provide a general roadmap for extracting transition matrix elements using precise frequency measurements. We demonstrate that such measurements can serve as a best global benchmark of the spectroscopic accuracy that is required for the development of high-precision predictive methods. These magic-zero wavelengths are also needed for state-selective atom manipulation for implementation of quantum logic operations. We also identify five magic wavelengths of the $5s^2\\ ^1S_0 - 5s5p\\ ^3P_0$ Sr clock transition between 350 nm and 500 nm which can also serve as precision benchmarks.
Hsieh, David
We report high-resolution spin-resolved photoemission spectroscopy (spin-ARPES) measurements on the parent compound Sb of the recently discovered three-dimensional topological insulator Bi1?xSbx (Hsieh et al 2008 Nature ...
Milagro Magic Paint: Does it Work?
Milagro Magic Paint: Does it Work? John A.J. Matthews and Bill Miller johnm@phys.unm.edu University NM sunshine · Solution was to paint with ASTEC ceramic finish #900 John Matthews/Auger North Meeting/CSU/Feb. 17-19, 2009 p.2/7 #12;Will Milagro magic paint work for Auger? · Fermilab sent us 3 Auger South
Vladimir Baryshevsky
2002-12-09
New experiment arrangement to study spin rotation and oscillation of particles of gas target through which beam of high energy particles passes is discussed. Such experiment arrangement make it realizable for storage ring and allows to study zero-angle scattering amplitude at highest possible energies. Life-time of particle beam in storage ring can reach several hours and even days. Life-time of particle in gas target (gas trap) is long too. Particles circulate in storage ring with frequency $\
Chinese Magic in Loop Integrals
B. F. L. Ward
2011-06-02
We present an approach to higher point loop integrals using Chinese magic in the virtual loop integration variable. We show, using the five point function in the important e^+e^-\\to f\\bar{f}+\\gamma process for ISR as a pedagogical vehicle, that we get an expression for it directly reduced to one scalar 5-point function and 4-, 3-, and 2- point integrals, thereby avoiding the computation of the usual three tensor 5-pt Passarino-Veltman reduction. We argue that this offers potential for greater numerical stability.
Solar Magic | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop Inc JumpHeter Battery TechnologySocovoltaic SystemsInternationalGlobal JumpMagic
Magic Valley | Open Energy Information
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Waidyawansa, Dinayadura Buddhini [OHIO U.
2013-08-01
The beam normal single spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable of the imaginary part of the two-photon exchange process. Moreover, it is a potential source of false asymmetry in parity violating electron scattering experiments. The Q{sub weak} experiment uses parity violating electron scattering to make a direct measurement of the weak charge of the proton. The targeted 4% measurement of the weak charge of the proton probes for parity violating new physics beyond the Standard Model. The beam normal single spin asymmetry at Q{sub weak} kinematics is at least three orders of magnitude larger than 5 ppb precision of the parity violating asymmetry. To better understand this parity conserving background, the Q{sub weak} Collaboration has performed elastic scattering measurements with fully transversely polarized electron beam on the proton and aluminum. This dissertation presents the analysis of the 3% measurement (1.3% statistical and 2.6% systematic) of beam normal single spin asymmetry in electronproton scattering at a Q2 of 0.025 (GeV/c)2. It is the most precise existing measurement of beam normal single spin asymmetry available at the time. A measurement of this precision helps to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process.
Magic Words: How Language Augments Human Computation
Clark, Andy
1998-01-01
Of course, words aren’t magic. Neither are sextants, compasses, maps, slide rules and all the other paraphenelia which have accreted around the basic biological brains of homo sapiens. In the case of these other tools and ...
MODULAR MAGIC SUDOKU JOHN LORCH AND ELLEN WELD
Lorch, John D.
MODULAR MAGIC SUDOKU JOHN LORCH AND ELLEN WELD Abstract. A modular magic sudoku solution. 05B15. 1 #12;2 JOHN LORCH AND ELLEN WELD sudoku solution in (1) and the solution x2 given in Section
Magic State Distillation and Gate Compilation in Quantum Algorithms for Quantum Chemistry
Colin J. Trout; Kenneth R. Brown
2015-01-29
Quantum algorithms for quantum chemistry map the dynamics of electrons in a molecule to the dynamics of a coupled spin system. To reach chemical accuracy for interesting molecules, a large number of quantum gates must be applied which implies the need for quantum error correction and fault-tolerant quantum computation. Arbitrary fault-tolerant operations can be constructed from a small, universal set of fault-tolerant operations by gate compilation. Quantum chemistry algorithms are compiled by decomposing the dynamics of the coupled spin-system using a Trotter formula, synthesizing the decomposed dynamics using Clifford operations and single-qubit rotations, and finally approximating the single-qubit rotations by a sequence of fault-tolerant single-qubit gates. Certain fault-tolerant gates rely on the preparation of specific single-qubit states referred to as magic states. As a result, gate compilation and magic state distillation are critical for solving quantum chemistry problems on a quantum computer. We review recent progress that has improved the efficiency of gate compilation and magic state distillation by orders of magnitude.
The Magic and Mysteries of Water
Richmond, Geraldine L.
The Magic and Mysteries of Water Speaker: Prof. Geri Richmond University of Oregon Water is ubiquitous in our lives. Covering more than two thirds of this planet, water surfaces provide a unique role in controlling our climate. In our bodies, water is the `canal of life', transporting and passing
The reflecting surface of the MAGIC-II Telescope
D. Bastieri; J. Arnold; C. Baixeras; O. Citterio; F. Dazzi; B. De Lotto; M. Doro; M. Ghigo; E. Giro; F. Goebel; R. Kosyra; E. Lorenz; M. Mariotti; R. Mirzoyan; R. Paoletti; G. Pareschi; D. Pascoli; A. Pepato; L. Peruzzo; A. Saggion; P. Sartori; A. Sillanpää
2007-09-10
The MAGIC Collaboration is building a second telescope, MAGIC II, improving the design of the current MAGIC Telescope. MAGIC II is being built at 85 m of distance from MAGIC I, and will also feature a huge reflecting surface of ~240 m$^2$ of area. One of the improvement is the design for the mirror of MAGIC II, that are lighter and larger, being square of 1 m of side and weighting around 15 kg. For the development and production of the new mirrors, two different techniques, both reliable and affordable in price, were selected: the diamond milling of aluminium surfaces and the cold slumping of thin glass panes. As tests for the second one are still ongoing, we present a description of the diamond milling technique, and its application and performance to the produced mirrors.
Magic wavelengths in the alkaline earth ions
Kaur, Jasmeet; Arora, Bindiya; Sahoo, B K
2015-01-01
We present magic wavelengths for the $nS$ - $nP_{1/2,3/2}$ and $nS$ - $mD_{3/2,5/2}$ transitions, with the respective ground and first excited $D$ states principal quantum numbers $n$ and $m$, in the Mg$^+$, Ca$^+$, Sr$^+$ and Ba$^+$ alkaline earth ions for linearly polarized lights by plotting dynamic polarizatbilities of the $nS$, $nP_{1/2,3/2}$ and $mD_{3/2,5/2}$ states of the ions. These dynamic polarizabilities are evaluated by employing a relativistic all-order perturbative method and their accuracies are ratified by comparing their static values with the available high precision experimental or other theoretical results. Moreover, some of the magic wavelengths identified by us in Ca$^+$ concurs with the recent measurements reported in [{\\bf Phys. Rev. Lett. 114, 223001 (2015)}]. Knowledge of these magic wavelengths are propitious to carry out many proposed high precision measurements trapping the above ions in the electric fields with the corresponding frequencies.
Liz O'Brien Social Research Group Magical place
and Market Research who organised and facilitated eight of the sixteen discussion groups and contributedLiz O'Brien Social Research Group A sort of Magical place People's experiences of woodlands in northwest and southeast England #12;Liz O'Brien Social Research Group Forest Research 1A Sort of Magical
Magic Reservoir Geothermal Area | Open Energy Information
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Lab scientists track Santa's magical journey
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse Bergkamp Graduate student Subtask22BackgroundLabSanta's magical journey
MAGIC: Marine ARM GPCI Investigation of Clouds
Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M
2012-10-03
The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.
Observation of GRBs by the MAGIC Telescope, Status and Outlook
D. Bastieri; N. Galante; M. Garczarczyk; M. Gaug; F. Longo; S. Mizobuchi; V. Scapin
2007-09-10
Observation of Gamma Ray Bursts (GRBs) in the Very High Energy (VHE) domain will provide important information on the physical conditions in GRB outflows. The MAGIC telescope is the best suited Imaging Atmospheric Cherenkov Telescope (IACT) for these observations. Thanks to its fast repositioning time and low energy threshold, MAGIC is able to start quickly the follow-up observation, triggered by an alert from the GRB Coordinates Network (GCN), and observe the prompt emission and early afterglow phase from GRBs. In the last two years of operation several GRB follow-up observations were performed by MAGIC, however, until now without successful detection of VHE gamma rays above threshold energies >100 GeV. In this paper we revise the expectations for the GRB observations with MAGIC, based on the experience from the last years of operation.
The wonder of magic : eliciting wonder and amazing its expression
Raphael, Seth
2007-01-01
The wonder that occurs while watching a good magic trick or admiring a gorgeous natural vista is a strong emotion that has not been well studied. Educators, media producers, entertainers, scientists and magicians could all ...
The Chemistry Magic Show Captivates Kids | GE Global Research
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Chemistry Magic Show Captivates Kids Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to...
The MAGIC Project: Contributions to ICRC 2005, Pune, India, Part 2: Future Plans and Developments
J. Albert i Fort
2005-08-15
Contributions by the MAGIC collaboration to ICRC 2005, Pune, India, Part 2: Future Plans and Developments (9 contributions)
Status and First Results of the MAGIC Telescope
J. Cortina; for the MAGIC collaboration
2004-07-22
The 17 m MAGIC Cherenkov telescope for gamma ray astronomy between 30 and 300 GeV started operations in its final configuration in October 2003 and is currently well into its calibration phase. Here I report on its present status and its first gamma ray source detections.
Magic wavelength for the hydrogen 1S-2S transition
Kawasaki, Akio
The magic wavelength for an optical lattice for hydrogen atoms that cancels the lowest order ac Stark shift of the 1S-2S transition is calculated to be 513 nm. The magnitudes of the ac Stark shift ?E = ?119 Hz/(kW/cm[superscript ...
Magic Wavelength for Hydrogen 1S-2S Transition
Kawasaki, Akio
2015-01-01
The magic wavelength for an optical lattice for hydrogen atoms that cancels the first order AC Stark shift of 1S-2S transition is calculated to be 513 nm. The amount of AC Stark shift $ \\Delta E = -1.19$ kHz/(10kW/cm$^2$) and the slope $d\\Delta E/d \
Magic Materials: a theory of deep hierarchical architectures
Poggio, Tomaso
and complex cells, such as those in V1, can naturally implement such estimates. Hierarchical architecturesMagic Materials: a theory of deep hierarchical architectures for learning sensory representations Architectures) Fabio Anselmi, Joel Z Leibo, Lorenzo Rosasco, Jim Mutch, Andrea Tacchetti, Tomaso Poggio May 6
Discovery of TeV gamma-ray emission from the pulsar wind nebula 3C 58 by MAGIC
López-Coto, R; Bednarek, W; Blanch, O; Cortina, J; Wilhelmi, E de Ona; Martín, J; Pérez-Torres, M A
2015-01-01
The pulsar wind nebula (PWN) 3C 58 has been proposed as a good candidate for detection at VHE (VHE; E>100 GeV) for many years. It is powered by one of the highest spin-down power pulsars known (5\\% of Crab pulsar) and it has been compared to the Crab Nebula due to its morphology. This object was previously observed by imaging atmospheric Cherenkov telescopes (Whipple, VERITAS and MAGIC), and upper limit of 2.4\\% Crab Unit (C.U.) at VHE. It was detected by Fermi-LAT with a spectrum extending beyond 100 GeV. We analyzed 81 hours of 3C 58 data taken with the MAGIC telescopes and we detected VHE gamma-ray emission with a significance of 5.7 sigma and an integral flux of 0.65\\% C.U. above 1 TeV. We report the first significant detection of PWN 3C 58 at TeV energies. According to our results 3C 58 is the least luminous VHE gamma-ray PWN ever detected at VHE and the one with the lowest flux at VHE to date. We compare our results with the expectations of time-dependent models in which electrons up-scatter photon fiel...
On spectroscopic factors of magic and semimagic nuclei
Saperstein, E. E. [Kurchatov Institute, 123182 Moscow (Russian Federation); Gnezdilov, N. V. [Kurchatov Institute, 123182 Moscow, Russia and National Research Nuclear University MEPhI, 115409 Moscow (Russian Federation); Tolokonnikov, S. V. [Kurchatov Institute, 123182 Moscow, Russia and Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation)
2014-10-15
Single-particle spectroscopic factors (SF) of magic and semimagic nuclei are analyzed within the self-consistent theory of finite Fermi systems. The the in-volume energy dependence of the mass operator ? is taken into account in addition to the energy dependence induced by the surface-phonon coupling effects which is commonly considered. It appears due to the effect of high-lying collective and non-collective particle-hole excitations and persists in nuclear matter. The self-consistent basis of the energy density functional method by Fayans et al. is used. Both the surface and in-volume contributions to the SFs turned out to be of comparable magnitude. Results for magic {sup 208}Pb nucleus and semimagic lead isotopes are presented.
D. Patel; U. Garg; M. Fujiwara; T. Adachi; H. Akimune; G. P. A. Berg; M. N. Harakeh; M. Itoh; C. Iwamoto; A. Long; J. T. Matta; T. Murakami; A. Okamoto; K. Sault; R. Talwar; M. Uchida; M. Yosoi
2013-08-09
Using inelastic $\\alpha$-scattering at extremely forward angles, including $0^\\circ$, the strength distributions of the isoscalar giant monopole resonance (ISGMR) have been measured in the $^{204,206,208}$Pb isotopes in order to examine the proposed mutually enhanced magicity (MEM) effect on the nuclear incompressibility. The MEM effect had been suggested as a likely explanation of the "softness" of nuclear incompressibility observed in the ISGMR measurements in the Sn and Cd isotopes. Our experimental results rule out any manifestation of the MEM effect in nuclear incompressibility and leave the question of the softness of the open-shell nuclei unresolved still.
Spin transport and spin polarization properties in double-stranded DNA
Simchi, Hamidreza; Esmaeilzadeh, Mahdi Mazidabadi, Hossein
2013-11-21
We study the spin-dependent electron transport through a double-stranded DNA (dsDNA) using the Bogoliubov-de Gennes equations and non-equilibrium Green's function method. We calculate the spin-dependent electron conductance and spin-polarization for different lengths, helix angles, twist angles of dsDNA, the environment-induced dephasing factors, and hopping integral. It is shown that the conductance decreases by increasing the length and dephasing factor. Also, we show that the spin-polarization depends on the helical symmetry and the length of DNA. It is shown that the double-stranded DNA can act as a perfect spin filter. Finally, we show that the sign of spin polarization can be inverted from +1 (?1) to ?1 (+1) for some values of hopping integral.
Small Angle Neutron Scattering
Urban, Volker S [ORNL
2012-01-01
Small Angle Neutron Scattering (SANS) probes structural details at the nanometer scale in a non-destructive way. This article gives an introduction to scientists who have no prior small-angle scattering knowledge, but who seek a technique that allows elucidating structural information in challenging situations that thwart approaches by other methods. SANS is applicable to a wide variety of materials including metals and alloys, ceramics, concrete, glasses, polymers, composites and biological materials. Isotope and magnetic interactions provide unique methods for labeling and contrast variation to highlight specific structural features of interest. In situ studies of a material s responses to temperature, pressure, shear, magnetic and electric fields, etc., are feasible as a result of the high penetrating power of neutrons. SANS provides statistical information on significant structural features averaged over the probed sample volume, and one can use SANS to quantify with high precision the structural details that are observed, for example, in electron microscopy. Neutron scattering is non-destructive; there is no need to cut specimens into thin sections, and neutrons penetrate deeply, providing information on the bulk material, free from surface effects. The basic principles of a SANS experiment are fairly simple, but the measurement, analysis and interpretation of small angle scattering data involves theoretical concepts that are unique to the technique and that are not widely known. This article includes a concise description of the basics, as well as practical know-how that is essential for a successful SANS experiment.
ROTATION AXIS VARIATION DUE TO SPIN ORBIT RESONANCE Giovanni Gallavotti \\Lambda
and the plane orthogonal to the spin: equinox line); ' is the angle between the spin ecliptic node. The e = 0 model was in fact used by D'Alembert, [L], to deduce his celebrated theory of the equinox
Magic Valley Electric Coop Inc | Open Energy Information
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MAGIC upper limits on the GRB 090102 afterglow
Aleksi?, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; de Almeida, U Barres; Barrio, J A; González, J Becerra; Bednarek, W; Berger, K; Bernardini, E; Biland, A; Blanch, O; Bock, R K; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Fidalgo, D Carreto; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Mendez, C Delgado; Doert, M; Domínguez, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Farina, E; Ferenc, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Giavitto, G; Godinovi?, N; Muñoz, A González; Gozzini, S R; Hadasch, D; Hayashida, M; Herrero, A; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Knoetig, M L; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Meucci, M; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Nowak, N; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Partini, S; Persic, M; Prada, F; Moroni, P G Prada; Prandini, E; Preziuso, S; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saggion, A; Saito, T; Saito, K; Salvati, M; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Sun, S; Suri?, T; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzi?, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Vogler, P; Wagner, R M; Zandanel, F; Zanin, R; Bouvier, A; Tajima, H; Longo, F
2013-01-01
Indications of a GeV component in the emission from GRBs are known since the EGRET observations during the 1990's and they have been confirmed by the data of the Fermi satellite. These results have, however, shown that our understanding of GRB physics is still unsatisfactory. The new generation of Cherenkov observatories and in particular the MAGIC telescope, allow for the first time the possibility to extend the measurement of GRBs from several tens up to hundreds of GeV energy range. Both leptonic and hadronic processes have been suggested to explain the possible GeV/TeV counterpart of GRBs. Observations with ground-based telescopes of very high energy photons (E>30 GeV) from these sources are going to play a key role in discriminating among the different proposed emission mechanisms, which are barely distinguishable at lower energies. MAGIC telescope observations of the GRB 090102 (z=1.547) field and Fermi Large Area Telescope (LAT) data in the same time interval are analysed to derive upper limits of the ...
Search for spin-orbit-force reduction at {sup 106,108}Zr around r-process path
Sumikama, T.; Yoshinaga, K. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Watanabe, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); and others
2012-11-12
Shell gap at the magic number N= 82 is important to reproduce the 2nd peak of r-process abundance. If a spin-orbit force is reduced in a very neutron-rich region, a shell quenching at N= 82 and a new shell closure at N70 are predicted. A shell evolution by the spin-orbit-force reduction can be searched for through the shape evolution of Zr isotopes around an expected double magic nuclei, {sup 110}Zr(Z = 40,N = 70). We performed {beta}-{gamma} and isomer spectroscopy at RIBF to observe low-lying states in {sup 106,108}Zr. The present results indicate a well deformed shape for {sup 106,108}Zr. The drastic reduction of the spin-orbit force most likely does not occur around {sup 110}Zr on an r-process path.
A New Spin on Photoemission Spectroscopy
Advanced Light Source; Jozwiak, Chris
2008-12-18
The electronic spin degree of freedom is of general fundamental importance to all matter. Understanding its complex roles and behavior in the solid state, particularly in highly correlated and magnetic materials, has grown increasingly desirable as technology demands advanced devices and materials based on ever stricter comprehension and control of the electron spin. However, direct and efficient spin dependent probes of electronic structure are currently lacking. Angle Resolved Photoemission Spectroscopy (ARPES) has become one of the most successful experimental tools for elucidating solid state electronic structures, bolstered bycontinual breakthroughs in efficient instrumentation. In contrast, spin-resolved photoemission spectroscopy has lagged behind due to a lack of similar instrumental advances. The power of photoemission spectroscopy and the pertinence of electronic spin in the current research climate combine to make breakthroughs in Spin and Angle Resolved Photoemission Spectroscopy (SARPES) a high priority . This thesis details the development of a unique instrument for efficient SARPES and represents a radical departure from conventional methods. A custom designed spin polarimeter based on low energy exchange scattering is developed, with projected efficiency gains of two orders of magnitude over current state-of-the-art polarimeters. For energy analysis, the popular hemispherical analyzer is eschewed for a custom Time-of-Flight (TOF) analyzer offering an additional order of magnitude gain in efficiency. The combined instrument signifies the breakthrough needed to perform the high resolution SARPES experiments necessary for untangling the complex spin-dependent electronic structures central to today?s condensed matter physics.
Nuclear spin circular dichroism
Vaara, Juha; Rizzo, Antonio; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia
2014-04-07
Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.
Classical gravitational spin-spin interaction
W. B. Bonnor
2002-01-30
I obtain an exact, axially symmetric, stationary solution of Einstein's equations for two massless spinning particles. The term representing the spin-spin interaction agrees with recently published approximate work. The spin-spin force appears to be proportional to the inverse fourth power of the coordinate distance between the particles.
A Review of "Magic and Masculinity in Early Modern English Drama" by Ian McAdam
Tiffany, Grace
2011-01-01
?s mobility in traversing both physical and culturally sanctioned boundaries. Ian McAdam. Magic and Masculinity in Early Modern English Drama. Pittsburgh: Duquesne University Press, 2009. v + 466 pp. $60. Review by grace tiffany, western michigan... university. Ambitiously, Ian McAdam surveys over half a century?s worth of selected plays by seven major authors to advance his thesis regarding the changing significance of magic and magicians to the early modern English intellect. This book?s eight...
Experimental evidences of a large extrinsic spin Hall effect in AuW alloy
Laczkowski, P.; Rojas-Sánchez, J.-C.
2014-04-07
We report an experimental study of a gold-tungsten alloy (7 at. % W concentration in Au host) displaying remarkable properties for spintronics applications using both magneto-transport in lateral spin valve devices and spin-pumping with inverse spin Hall effect experiments. A very large spin Hall angle of about 10% is consistently found using both techniques with the reliable spin diffusion length of 2?nm estimated by the spin sink experiments in the lateral spin valves. With its chemical stability, high resistivity, and small induced damping, this AuW alloy may find applications in the nearest future.
Andersen, John A. (Alburquerque, NM); Flanigan, John J. (Alburquerque, NM); Kindley, Robert J. (Alburquerque, NM)
1978-01-01
The disclosure relates to an apparatus for spin ejecting a body having a flat plate base containing bosses. The apparatus has a base plate and a main ejection shaft extending perpendicularly from the base plate. A compressible cylindrical spring is disposed about the shaft. Bearings are located between the shaft and the spring. A housing containing a helical aperture releasably engages the base plate and surrounds the shaft bearings and the spring. A piston having an aperture follower disposed in the housing aperture is seated on the spring and is guided by the shaft and the aperture. The spring is compressed and when released causes the piston to spin eject the body.
Discovery of TeV gamma-ray emission from the Pulsar Wind Nebula 3C 58 by MAGIC
Bigas, O Blanch; Carmona, E; Pérez-Torres, M A
2015-01-01
The Pulsar Wind Nebula (PWN) 3C 58 is energized by one of the highest spin-down power pulsars known (5% of Crab pulsar) and it has been compared to the Crab Nebula due to their morphological similarities. This object was detected by Fermi-LAT with a spectrum extending beyond 100 GeV. We analyzed 81 hours of 3C 58 data taken with the MAGIC telescopes and we detected VHE gamma-ray emission for the first time at TeV energies with a significance of 5.7 sigma and an integral flux of 0.65% C.U. above 1 TeV. The differential energy spectrum between 400 GeV and 10 TeV is well described by a power-law function $d\\Phi/dE=f_{o}(E/1TeV)^{-\\Gamma}$ with $f_{o}=(2.0\\pm0.4stat\\pm0.6sys) 10^{-13}cm^{-2}s^{-1}TeV^{-1}$ and $\\Gamma=2.4\\pm0.2sta\\pm0.2sys$. This leads 3C 58 to be the least luminous PWN ever detected at VHE and the one with the lowest flux at VHE to date. According to time-dependent models in which electrons up-scatter photon fields, the best representation favors a distance to the PWN of 2 kpc and FIR comparable...
Spin rotation of polarized beams in high energy storage ring
V. G. Baryshevsky
2006-03-23
The equations for spin evolution of a particle in a storage ring are obtained considering contributions from the tensor electric and magnetic polarizabilities of the particle along with the contributions from spin rotation and birefringence effect in polarized matter of an internal target. % Study of the spin rotation and birefringence effects for a particle in a high energy storage ring provides for measurement both the spin-dependent real part of the coherent elastic zero-angle scattering amplitude and tensor electric (magnetic) polarizabilities.
Demand Response Spinning Reserve Demonstration
2007-01-01
F) Enhanced ACP Date RAA ACP Demand Response – SpinningReserve Demonstration Demand Response – Spinning Reservesupply spinning reserve. Demand Response – Spinning Reserve
Description of Excitations in Odd Non-magic Nuclei by the Green's Function Method
A. V. Avdeenkov; S. P. Kamerdzhiev
2000-06-13
General equations for one- particle Green function in non- magic nuclei have been derived where a pairing mechanism, which is analogous to the Bardeen- Cooper- Schrieffer one, has been singled out explicitely. A "refining" procedure for the phenomenological single- particle energies and pairing gaps is formulated to avoid double counting of the phonon mixing if the initial data of the problem are these phenomenological quantities. The general equations obtained have been written in the squared phonon creation amplitude approximation. This corresponds to taking quasiparticle$\\otimes$phonon configurations into account and, as shown in the work, is a good approximation for semi- magic nuclei. Using this approximation the secular equation to calculate excitations of odd non- magic nuclei has been obtained. The equation takes ground state correlations into account completely and contains only the squared energy variable. Distributions of single- particle strength in 119Sn and 121}Sn have been calculated and reasonable agreement with the available experiment has been obtained.
Liquid Crystal Pretilt and Azimuth Angle Study of Stacked Alignment Layers
angles for the liquid crystal. It is based on stacking both photo- aligned polymer and rubbed polyimide comprise of both photo-aligned horizontal polymer and rubbed vertical polyimide. The advantage alignment polyimide JALS2021 form JSR Corporation is spin coated on the substrate. Then it is baked inside
RHIC spin physics: Proceedings. Volume 7
1998-12-01
This proceedings compiles one-page summaries and five transparencies for each talk, with the intention that the speaker should include a web location for additional information in the summary. Also, email addresses are given with the participant list. The order follows the agenda: gluon, polarimetry, accelerator, W production and quark/antiquark polarization, parity violation searches, transversity, single transverse spin, small angle elastic scattering, and the final talk on ep collisions at RHIC. The authors begin the Proceedings with the full set of transparencies from Bob Jaffe`s colloquium on spin, by popular request.
Conversion of pure spin current to charge current in amorphous bismuth
Emoto, H.; Ando, Y.; Shinjo, T.; Shiraishi, M.; Shikoh, E.; Fuseya, Y.
2014-05-07
Spin Hall angle and spin diffusion length in amorphous bismuth (Bi) are investigated by using conversion of a pure spin current to a charge current in a spin pumping technique. In Bi/Ni{sub 80}Fe{sub 20}/Si(100) sample, a clear direct current (DC) electromotive force due to the inverse spin Hall effect of the Bi layer is observed at room temperature under a ferromagnetic resonance condition of the Ni{sub 80}Fe{sub 20} layer. From the Bi thickness dependence of the DC electromotive force, the spin Hall angle and the spin diffusion length of the amorphous Bi film are estimated to be 0.02 and 8?nm, respectively.
OPENING ANGLES OF COLLAPSAR JETS
Mizuta, Akira; Ioka, Kunihito
2013-11-10
We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle is given by ?{sub j} ? 1/5?{sub 0} and infer the initial Lorentz factor of the jet at the central engine, ?{sub 0}, is a few for existing observations of ?{sub j}. The jet keeps the Lorentz factor low inside the star by converging cylindrically via collimation shocks under the cocoon pressure and accelerates at jet breakout before the free expansion to a hollow-cone structure. In this new picture, the GRB duration is determined by the sound crossing time of the cocoon, after which the opening angle widens, reducing the apparent luminosity. Some bursts violating the maximum opening angle ?{sub j,{sub max}} ? 1/5 ? 12° imply the existence of a baryon-rich sheath or a long-acting jet. We can explain the slopes in both Amati and Yonetoku spectral relations using an off-centered photosphere model, if we make only one assumption that the total jet luminosity is proportional to the initial Lorentz factor of the jet. We also numerically calibrate the pre-breakout model (Bromberg et al.) for later use.
An Examination of Magical Beliefs as Predictors of Obsessive-Compulsive Symptom Dimensions
Spears, Lauren
2014-08-31
in front of a stove and repeatedly feeling the knobs to make sure that they are in the right place may require magical thinking, as the individual must continually deny the veracity of visual and other sensory input that they are receiving at the time...
Constraints on the Skyrme Equations of State from Properties of Doubly Magic Nuclei
B. Alex Brown
2013-08-16
I use properties of doubly-magic nuclei to constrain nuclear matter and neutron matter equations of state. I conclude that the data determined the value of the neutron equation of state and the symmetry energy near a density of $\\rho_{on}$ = 0.10 nucleons/fm$^{3}$. The slope at that point is constrained by the value of the neutron skin.
A Dimension Space for Designing Richly Interactive Systems: a Perspective on the MagicBoards
Nigay, Laurence
A Dimension Space for Designing Richly Interactive Systems: a Perspective on the Magic is intended to help designers understand both the physical and virtual entities from which their systems and informational density. The Dimension Space is applied to two new systems developed at Grenoble, exposing design
To Mindstorms and Beyond: Evolution of a Construction Kit for Magical Machines
on technology, the intent is to reveal the process by which we were led along in creating these systems a special relationship to the world of technology we are living in. The magic of technology, so much a part by the wonder of a machine acting like a pet. Designing tools that allow children to add computation
A unit vector for characterizing the spin polarization of free electron
Chun-Fang Li; Yan Wang
2010-08-05
New degrees of freedom having the form of a unit vector are identified for characterizing the spin polarization of free electron. It is shown that when only the spin is considered, the non-commutativity of the Cartesian components of the Pauli vector allows us to use the azimuthal angle of a second direction, denoted by unit vector $\\mathbf I$, with respect to the quantization direction to characterize the spin polarization. The rotation of $\\mathbf I$ through an angle about the quantization axis leads to a rotation of the spin polarization vector through twice the angle about the same axis. Discussions are also made in Heisenberg picture as well. Upon utilizing this approach to a free electron and letting the quantization direction for each plane wave be the wave vector, we arrive at a representation in which the unit vector $\\mathbf I$ functions as an independent index to characterize the spin polarization.
Protein MAS NMR methodology and structural analysis of protein assemblies
Bayro, Marvin J
2010-01-01
Methodological developments and applications of solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, with particular emphasis on the analysis of protein structure, are described in this thesis. ...
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without sidebands. We have adapted it to broad spectra and fast magic-angle spinning by accounting for long pulses (comparable to the dwell time in tsub 1) and short rotation...
Higher Order Amyloid Fibril Structure by MAS NMR and DNP Spectroscopy
Debelouchina, Galia T.
Protein magic angle spinning (MAS) NMR spectroscopy has generated structural models of several amyloid fibril systems, thus providing valuable information regarding the forces and interactions that confer the extraordinary ...
Unitary spin squeezing by interference-based quantum erasure
Mingfeng Wang; Weizhi Qu; Pengxiong Li; Han Bao; Yanhong Xiao
2015-02-06
We propose an all-optical approach for quantum erasure. Unwanted atom-light entanglement in spin squeezing is removed by destructive interference of three successive atom-light interaction process, with only the desired atom-atom interaction left. This scheme allows implementation of unitary one-axis and two-axis twisting spin squeezing using coherent light and cold or warm atomic ensemble. Calculations show that substantial spin squeezing is attainable under moderate experiment conditions. This proposal provides a new angle in using light to efficiently create many-body entanglement state with simple setups, and thus is promising for advancing technologies in quantum metrology and quantum information procession.
Spin - or, actually: Spin and Quantum Statistics
Juerg Froehlich
2008-02-29
The history of the discovery of electron spin and the Pauli principle and the mathematics of spin and quantum statistics are reviewed. Pauli's theory of the spinning electron and some of its many applications in mathematics and physics are considered in more detail. The role of the fact that the tree-level gyromagnetic factor of the electron has the value g = 2 in an analysis of stability (and instability) of matter in arbitrary external magnetic fields is highlighted. Radiative corrections and precision measurements of g are reviewed. The general connection between spin and statistics, the CPT theorem and the theory of braid statistics are described.
Cahaya, Adam B.; Tretiakov, O. A. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Bauer, Gerrit E. W. [Institute for Materials Research and WPI-AIMR, Tohoku University, Sendai 980-8577 (Japan); Kavli Institute of NanoScience, TU Delft Lorentzweg 1, 2628 CJ Delft (Netherlands)
2014-01-27
We derive expressions for the efficiency and figure of merit of two spin caloritronic devices based on the spin Seebeck effect (SSE), i.e., the generation of spin currents by a temperature gradient. The inverse spin Hall effect is conventionally used to detect the SSE and offers advantages for large area applications. We also propose a device that converts spin current into electric one by means of a spin-valve detector, which scales favorably to small sizes and approaches a figure of merit of 0.5 at room temperature.
Experimental observation of magic-wavelength behavior of {sup 87}Rb atoms in an optical lattice
Lundblad, N.; Schlosser, M.; Porto, J. V.
2010-03-15
We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped {sup 87}Rb atoms. Recent progress in metrology exploits so-called magic wavelengths, whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkali metals due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically trapped neutral atoms.
The MAGIC Telescope Project for Gamma Astronomy above 10 GeV
N. Magnussen
1998-05-14
A project to construct a 17 m diameter imaging air Cherenkov telescope, called the MAGIC Telescope, is described. The aim of the project is to close the observation gap in the gamma-ray sky extending from 10 GeV as the highest energy measurable by space-borne experiments to 300 GeV, the lowest energy measurable by the current generation of ground-based Cherenkov telescopes. The MAGIC Telescope will incorporate several new features in order to reach the very low energy threshold. At the same time the new technology will yield an improvement in sensitivity in the energy region where current Cherenkov telescopes are measuring by about an order of magnitude.
Hybrid magic state distillation for universal fault-tolerant quantum computation
Wenqiang Zheng; Yafei Yu; Jian Pan; Jingfu Zhang; Jun Li; Zhaokai Li; Dieter Suter; Xianyi Zhou; Xinhua Peng; Jiangfeng Du
2014-12-11
A set of stabilizer operations augmented by some special initial states known as 'magic states', gives the possibility of universal fault-tolerant quantum computation. However, magic state preparation inevitably involves nonideal operations that introduce noise. The most common method to eliminate the noise is magic state distillation (MSD) by stabilizer operations. Here we propose a hybrid MSD protocol by connecting a four-qubit H-type MSD with a five-qubit T-type MSD, in order to overcome some disadvantages of the previous MSD protocols. The hybrid MSD protocol further integrates distillable ranges of different existing MSD protocols and extends the T-type distillable range to the stabilizer octahedron edges. And it provides considerable improvement in qubit cost for almost all of the distillable range. Moreover, we experimentally demonstrate the four-qubit H-type MSD protocol using nuclear magnetic resonance technology, together with the previous five-qubit MSD experiment, to show the feasibility of the hybrid MSD protocol.
Caustic graphene plasmons with Kelvin angle
Shi, Xihang; Gao, Fei; Xu, Hongyi; Yang, Zhaoju; Zhang, Baile
2015-01-01
A century-long argument made by Lord Kelvin that all swimming objects have an effective Mach number of 3, corresponding to the Kelvin angle of 19.5 degree for ship waves, has been recently challenged with the conclusion that the Kelvin angle should gradually transit to the Mach angle as the ship velocity increases. Here we show that a similar phenomenon can happen for graphene plasmons. By analyzing the caustic wave pattern of graphene plasmons stimulated by a swift charged particle moving uniformly above graphene, we show that at low velocities of the charged particle, the caustics of graphene plasmons form the Kelvin angle. At large velocities of the particle, the caustics disappear and the effective semi-angle of the wave pattern approaches the Mach angle. Our study introduces caustic wave theory to the field of graphene plasmonics, and reveals a novel physical picture of graphene plasmon excitation during electron energy-loss spectroscopy measurement.
Instantons As Unitary Spin Maker
Mauro Napsuciale; Andreas Wirzba; Mariana Kirchbach
2001-11-06
We investigate the relevance of the instanton-induced determinantal 't Hooft interaction to the eta-nucleon coupling within the framework of a three-flavor linear sigma model in the OZI-rule-respecting basis. Instantons, in combination with the spontaneous breaking of chiral symmetry, are shown to provide the major mechanism for the ideal mixing between pseudoscalar strange and non-strange quarkonia. As long as 't Hooft's interaction captures most of the basic features of the axial QCD gluon anomaly, we identify the anomaly as the main culprit for the appearance of octet flavor symmetry in the anomalous sectors of the pseudoscalar (and axial vector) mesons. Within this context, unitary spin is shown to be an accidental symmetry due to anomalous gluon dynamics rather than a fundamental symmetry in its own right. Though we find the eta-nucleon coupling constant to obey a Goldberger-Treiman like relation, the latter does not take its origin from a pole dominance of the induced pseudoscalar form factor of the octet axial current, but from a subtle flavor-mixing mechanism that is traced back to instanton dynamics. The model presented allows for possible generalizations to non-ideal mixing angles and different values of the meson decay constants in the strange and non-strange sectors, respectively. Finally, we discuss the issue as to what extent the eta meson may be considered as a Goldstone boson under the constraints of the anomaly-produced unitary spin.
Optical detection of spin Hall effect in metals
Erve, O. M. J. van ‘t, E-mail: Olaf.Vanterve@nrl.navy.mil; Hanbicki, A. T.; McCreary, K. M.; Li, C. H.; Jonker, B. T. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)
2014-04-28
Optical techniques have been widely used to probe the spin Hall effect in semiconductors. In metals, however, only electrical methods such as nonlocal spin valve transport, ferromagnetic resonance, or spin torque transfer experiments have been successful. These methods require complex processing techniques and measuring setups. We show here that the spin Hall effect can be observed in non-magnetic metals such as Pt and ?-W, using a standard bench top magneto-optical Kerr system with very little sample preparation. Applying a square wave current and using Fourier analysis significantly improve our detection level. One can readily determine the angular dependence of the induced polarization on the bias current direction (very difficult to do with voltage detection), the orientation of the spin Hall induced polarization, and the sign of the spin Hall angle. This optical approach is free from the complications of various resistive effects, which can compromise voltage measurements. This opens up the study of spin Hall effect in metals to a variety of spin dynamic and spatial imaging experiments.
ETEAPOT: symplectic orbit/spin tracking code for all-electric storage rings
Talman, Richard M
2015-01-01
Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring "trap". At the "magic" kinetic energy of 232.792 MeV, proton spins are "frozen", for example always parallel to the instantaneous particle momentum. This paper describes an accelerator simulation code, ETEAPOT, a new component of the Unified Accelerator Libraries (UAL), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the non-constant particle velocity in electric rings give them significantly different properties, especially in weak focusing rings. Like the earlier code TEAPOT (for magnetic ring simulation) this code performs \\emph{exact tracking in an idealized (approximate) lattice} rather than the more conventional approach, which is \\emph{approximate tracking in a more nearly exact lattice.} The BMT equation des...
Limiting Emission Angle for Improved Solar Cell
Limiting Emission Angle for Improved Solar Cell Performance While direct light enters a solar cell will explore the potential benefits to limiting the emission angles of realistic solar cells, with efficiencies cooling, waste heat recovery and solar electricity generation, low values of the thermoelectric figure
Temperature dependence of the photo-induced inverse spin Hall effect in Au/InP hybrid structures
Khamari, Shailesh K. Porwal, S.; Dixit, V. K.; Sharma, T. K.
2014-01-27
Photo-induced Inverse Spin Hall Effect (ISHE) measurements on Au/InP hybrid structures are performed over a temperature range of 45 to 300?K. Dependence of the spin current density on the degree of circular polarization and also on the angle of incidence of laser beam confirms the ISHE origin of measured signal. The magnitude of ISHE increases with sample cooling. A numerical model based on the spin relaxation of non-equilibrium spin-polarized electrons is proposed for predicting the temperature dependence of ISHE. Our results indicate that the proposed device can be used as a spin photodetector over a wide temperature range.
Gong, Xingao
Adsorption of a carbon atom on the Ni38 magic cluster and three low-index nickel surfaces in the catalytic growth of carbon C nanotubes on clusters of transition metal catalysts. Here we focus by studying a C atom on a nickel Ni magic cluster (Ni38), which preserves fcc geometry, and three low
Spin caloritronics in graphene
Ghosh, Angsula; Frota, H. O.
2015-06-14
Spin caloritronics, the combination of spintronics with thermoelectrics, exploiting both the intrinsic spin of the electron and its associated magnetic moment in addition to its fundamental electronic charge and temperature, is an emerging technology mainly in the development of low-power-consumption technology. In this work, we study the thermoelectric properties of a Rashba dot attached to two single layer/bilayer graphene sheets as leads. The temperature difference on the two graphene leads induces a spin current, which depends on the temperature and chemical potential. We demonstrate that the Rashba dot behaves as a spin filter for selected values of the chemical potential and is able to filter electrons by their spin orientation. The spin thermopower has also been studied where the effects of the chemical potential, temperature, and also the Rashba term have been observed.
Torczynski, John R. (Albuquerque, NM)
2000-01-01
A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.
Spin Transport Shingo Katsumoto
Iye, Yasuhiro
-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan According to DARPA's definition, "Spintronics"[1] means "Spin Transport Electronics". The issue "Spin Trans- port" thus covers all the fields of spintronics and one devices. In semiconductor spintronics devices, we therefore utilize the differences in n, , m for up
Nan Zhao; Jan Honert; Berhard Schmid; Junichi Isoya; Mathew Markham; Daniel Twitchen; Fedor Jelezko; Ren-Bao Liu; Helmut Fedder; Jörg Wrachtrup
2012-04-29
Sensing single nuclear spins is a central challenge in magnetic resonance based imaging techniques. Although different methods and especially diamond defect based sensing and imaging techniques in principle have shown sufficient sensitivity, signals from single nuclear spins are usually too weak to be distinguished from background noise. Here, we present the detection and identification of remote single C-13 nuclear spins embedded in nuclear spin baths surrounding a single electron spins of a nitrogen-vacancy centre in diamond. With dynamical decoupling control of the centre electron spin, the weak magnetic field ~10 nT from a single nuclear spin located ~3 nm from the centre with hyperfine coupling as weak as ~500 Hz is amplified and detected. The quantum nature of the coupling is confirmed and precise position and the vector components of the nuclear field are determined. Given the distance over which nuclear magnetic fields can be detected the technique marks a firm step towards imaging, detecting and controlling nuclear spin species external to the diamond sensor.
Yoo, S. J. Ben
Spin Coating of Photoresists Revised: 2009-11-05 Source: www.microchemicals.eu e-Mail: sales@microchemicals.eu Basics of Spin Coating During spincoating, the centrifugal force the substrate. Advantages: The high resist film thickness homogeneity as well as the short coating times make
Towards a more accurate extraction of the SPICE netlist from MAGIC based layouts
Geronimo, G.D.
1998-08-01
The extraction of the SPICE netlist form MAGIC based layouts is investigated. It is assumed that the layout is fully coherent with the corresponding mask representation. The process of the extraction can be made in three steps: (1) extraction of .EXT file from layout, through MAGIC command extract; (2) extraction of the netlist from .EXT file through ext2spice extractor; and (3) correction of the netlist through ext2spice.corr program. Each of these steps introduces some approximations, most of which can be optimized, and some errors, most of which can be corrected. Aim of this work is the description of each step, of the approximations and errors on each step, and of the corresponding optimizations and corrections to be made in order to improve the accuracy of the extraction. The HP AMOS14TB 0.5 {micro}m process with linear capacitor and silicide block options and the corresponding SCN3MLC{_}SUBM.30.tech27 technology file will be used in the following examples.
The Magellanic Inter-Cloud Project (MAGIC) II: Slicing up the Bridge
Noel, Noelia E D; Read, Justin I; Dolphin, Andrew; Rix, Hans-Walter
2015-01-01
The origin of the gas in between the Magellanic Clouds (MCs), known as the Magellanic Bridge (MB), has always been the subject of controversy. To shed light into this, we present the results from the MAGIC II project aimed at probing the stellar populations in ten large fields located perpendicular to the main ridge-line of HI in the Inter-Cloud region. We secured these observations of the stellar populations in between the MCs using the WFI camera on the 2.2 m telescope in La Silla. Using colour-magnitude diagrams (CMDs), we trace stellar populations across the Inter-Cloud region. In good agreement with MAGIC I, we find significant intermediate-age stars in the Inter-Cloud region as well as young stars of a similar age to the last pericentre passage in between the MCs (~200 Myr ago). We show here that the young, intermediate-age and old stars have distinct spatial distributions. The young stars correlate well with the HI gas suggesting that they were either recently stripped from the SMC or formed in-situ. T...
Transverse Spin Physics: Recent Developments
Yuan, Feng
2009-01-01
that the transverse spin physics is playing a very importantrole in the strong interaction physics forhadronic spin physics. We will learn more about QCD dynamics
05Mar09 ANALYSISIn crisis, GE finds its deep bench not so magical By James B. Kelleher
Kuzmanovic, Aleksandar
05Mar09 ANALYSISIn crisis, GE finds its deep bench not so magical By James B. Kelleher CHICAGO, March 5 (Reuters) Crotonville, we have a problem. The travails of General Electric Co GE and expensive training program credited with creating those managers. In recent weeks, GE executives have
Nuclear Spins in Nanostructures
W. A. Coish; J. Baugh
2009-07-22
We review recent theoretical and experimental advances toward understanding the effects of nuclear spins in confined nanostructures. These systems, which include quantum dots, defect centers, and molecular magnets, are particularly interesting for their importance in quantum information processing devices, which aim to coherently manipulate single electron spins with high precision. On one hand, interactions between confined electron spins and a nuclear-spin environment provide a decoherence source for the electron, and on the other, a strong effective magnetic field that can be used to execute local coherent rotations. A great deal of effort has been directed toward understanding the details of the relevant decoherence processes and to find new methods to manipulate the coupled electron-nuclear system. A sequence of spectacular new results have provided understanding of spin-bath decoherence, nuclear spin diffusion, and preparation of the nuclear state through dynamic polarization and more general manipulation of the nuclear-spin density matrix through "state narrowing". These results demonstrate the richness of this physical system and promise many new mysteries for the future.
Overview of Processes Involved in Spin Transfer Collisions
Buttimore, N. H.
2008-04-30
An outline is provided of methods for polarizing antiprotons that include the possible use of channelling in a bent crystal and also the technique of scattering off leptons or protons at a suitably small angle. In the method of channelling it is suggested that the angular dependence of the analysing power of the incident particle is cubic in the angle for single scattering in the crystal when this takes place within the region of electromagnetic hadronic interference as is most likely for channelled particles. Polarization transfer in the scattering of antiprotons off leptons or protons is discussed in addition where emphasis is laid on the angular integrals over spin observables appropriate for spin filtering.
Measurement of the Kerr spin parameter by observation of a compact object's shadow
Hioki, Kenta; Maeda, Kei-ichi
2009-07-15
A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study how to determine the spin parameter and the inclination angle by observing the apparent shape of the shadow, which is distorted mainly by those two parameters. Defining some observables characterizing the apparent shape (its radius and distortion parameter), we find that the spin parameter and inclination angle of a Kerr black hole can be determined by the observation. This technique is also extended to the case of a Kerr naked singularity.
Angular dependence of the spin textures in two-dimensional chiral magnets
Tang, Dan; Qi, Yang
2015-05-28
The angular dependence of spin textures in thin helimagnetic films is investigated by a Monte Carlo simulation. When an external field is applied at an angle relative to the film normal, we find that the skyrmion states with broken axis-symmetric structure are able to persist over a wide range of angles by changing the spin orientation. In addition, the uniaxial anisotropy is able to stabilize the distorted skyrmions. This behavior reflects the robust topological stability of skyrmion states in helimagnets and favors their application in spintronic devices.
Spin splittings among charmed hadrons
Randy Lewis; Nilmani Mathur; R. M. Woloshyn
2001-09-19
The mass differences between spin-1/2 and spin-3/2 baryons are compared to the mass differences between spin-0 and spin-1 mesons. Results of simulations for charmed hadrons in the quenched approximation from a tadpole-improved anisotropic action are discussed in the context of other lattice calculations, quark model predictions, heavy quark symmetry predictions and experimental data.
Small Angle X-Ray Scattering Detector
Hessler, Jan P.
2004-06-15
A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.
Microscopic studies of nonlocal spin dynamics and spin transport (invited)
Adur, Rohan; Du, Chunhui; Cardellino, Jeremy; Scozzaro, Nicolas; Wolfe, Christopher S.; Wang, Hailong; Herman, Michael; Bhallamudi, Vidya P.; Pelekhov, Denis V.; Yang, Fengyuan; Hammel, P. Chris
2015-05-07
Understanding the behavior of spins coupling across interfaces in the study of spin current generation and transport is a fundamental challenge that is important for spintronics applications. The transfer of spin angular momentum from a ferromagnet into an adjacent normal material as a consequence of the precession of the magnetization of the ferromagnet is a process known as spin pumping. We find that, in certain circumstances, the insertion of an intervening normal metal can enhance spin pumping between an excited ferromagnetic magnetization and a normal metal layer as a consequence of improved spin conductance matching. We have studied this using inverse spin Hall effect and enhanced damping measurements. Scanned probe magnetic resonance techniques are a complementary tool in this context offering high resolution magnetic resonance imaging, localized spin excitation, and direct measurement of spin lifetimes or damping. Localized magnetic resonance studies of size-dependent spin dynamics in the absence of lithographic confinement in both ferromagnets and paramagnets reveal the close relationship between spin transport and spin lifetime at microscopic length scales. Finally, detection of ferromagnetic resonance of a ferromagnetic film using the photoluminescence of nitrogen vacancy spins in neighboring nanodiamonds demonstrates long-range spin transport between insulating materials, indicating the complexity and generality of spin transport in diverse, spatially separated, material systems.
Ship wakes: Kelvin or Mach angle?
Rabaud, Marc
2013-01-01
From the analysis of a set of airborne images of ship wakes, we show that the wake angles decrease as $U^{-1}$ at large velocities, in a way similar to the Mach cone for supersonic airplanes. This previously unnoticed Mach-like regime is in contradiction with the celebrated Kelvin prediction of a constant angle of $19.47\\degree$ independent of the ship's speed. We propose here a model, confirmed by numerical simulations, in which the finite size of the disturbance explains this transition between the Kelvin and Mach regimes at a Froude number $Fr = U/\\sqrt{gL} \\simeq 0.5$, where $L$ is the hull ship length.
Filter design for hybrid spin gates
Andreas Albrecht; Martin B. Plenio
2015-04-14
The impact of control sequences on the environmental coupling of a quantum system can be described in terms of a filter. Here we analyze how the coherent evolution of two interacting spins subject to periodic control pulses, at the example of a nitrogen vacancy center coupled to a nuclear spin, can be described in the filter framework in both the weak and the strong coupling limit. A universal functional dependence around the filter resonances then allows for tuning the coupling type and strength. Originally limited to small rotation angles, we show how the validity range of the filter description can be extended to the long time limit by time-sliced evolution sequences. Based on that insight, the construction of tunable, noise decoupled, conditional gates composed of alternating pulse sequences is proposed. In particular such an approach can lead to a significant improvement in fidelity as compared to a strictly periodic control sequence. Moreover we analyze the decoherence impact, the relation to the filter for classical noise known from dynamical decoupling sequences, and we outline how an alternating sequence can improve spin sensing protocols.
R. Annabestani; D. G. Cory; J. Emerson
2015-03-03
Any ensemble of quantum particles exhibits statistical fluctuations known as spin noise. Here, we provide a description of spin noise in the language of open quantum systems. The description unifies the signatures of spin noise under both strong and weak measurements. Further, the model accounts for arbitrary spin dynamics from an arbitrary initial state. In all cases we can find both the spin noise and its time correlation function.
Performance improvement study of a relativistic magnetron using MAGIC-3D
Maurya, S.; Singh, V.V.P., E-mail: smaurya@ceeri.ernet.in [Central Electronics Engineering Research Institute, Council of Scientific and Industrial Research, Pilani (India); Jain, R.K. [Center of Research in Microwave Tubes, Institute of Technology, Banaras Hindu University, Varanasi (India)
2011-07-01
A three dimensional particle-in-cell (PlC) code, MAGIC3D, is used to examine the performance improvement in a relativistic magnetron by perturbing technique. Asymmetrical metal rods of different length have been used to perturb the magnetic field in the annular sector of the resonant system. Enhancement up to 45% in the radiated output power has been obtained in the perturbed magnetic field case over the unperturbed one. It has also been found in the simulation that oscillation start up time is reduced by 16 %, and the amplitude of the nearest competing mode goes down 9dB compared to unperturbed case. Perturbed magnetic field also reduces the end caps current improving the efficiency. (author)
Atomic mass measurements of short-lived nuclides around the doubly-magic 208Pb
C. Weber; G. Audi; D. Beck; K. Blaum; G. Bollen; F. Herfurth; A. Kellerbauer; H. -J. Kluge; D. Lunney; S. Schwarz
2008-01-14
Accurate atomic mass measurements of neutron-deficient and neutron-rich nuclides around the doubly-magic 208Pb and of neutron-rich cesium isotopes were performed with the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. The masses of 145,147Cs, 181,183Tl, 186Tlm, 187Tl, 196Tlm, 205Tl, 197Pbm, 208Pb, 190 to 197Bi, 209,215,216Bi, 203,205,229Fr, and 214,229,230Ra were determined. The obtained relative mass uncertainty in the range of $2 \\cdot 10^{-7}$ to $2 \\cdot 10^{-8}$ is not only required for safe identification of isomeric states but also allows mapping the detailed structure of the mass surface. A mass adjustment procedure was carried out and the results included into the Atomic Mass Evaluation. The resulting separation energies are discussed and the mass spectrometric and laser spectroscopic data are examined for possible correlations.
Recent progress of GaAsP HPD development for the MAGIC telescope project
T. Y. Saito; M. Shayduk; M. V. Fonseca; M. Hayashida; E. Lorenz; K. Mannheim; R. Mirzoyan; T. Schweizer; M. Teshima
2007-09-13
Today the Hybrid Photon Detector (HPD) is one of the few low light level (LLL) sensors that can provide an excellent single and multiple photoelectron (ph.e.) amplitude resolution. The recently developed HPDs for the MAGIC telescope project with a GaAsP photocathode, namely the R9792U-40, provide a peak quantum efficiency (QE) of more than 50% and a pulse width of ~2 nsec. In addition, the afterpulsing rate of these tubes is very low compared to that of conventional photomultiplier tubes (PMTs), i.e. the value is ~300 times lower. Photocathode aging measurements showed life time of more than 10 years under standard operating conditions of the Cherenkov Telescopes. Here we want to report on the recent progress with the above mentioned HPDs.
Spin photonics and spin-photonic devices with dielectric metasurfaces
Liu, Yachao; Ke, Yougang; Zhou, Xinxing; Luo, Hailu; Wen, Shuangchun
2015-01-01
Dielectric metasurfaces with spatially varying birefringence and high transmission efficiency can exhibit exceptional abilities for controlling the photonic spin states. We present here some of our works on spin photonics and spin-photonic devices with metasurfaces. We develop a hybrid-order Poincare sphere to describe the evolution of spin states of wave propagation in the metasurface. Both the Berry curvature and the Pancharatnam-Berry phase on the hybrid-order Poincare sphere are demonstrated to be proportional to the variation of total angular momentum. Based on the spin-dependent property of Pancharatnam-Berry phase, we find that the photonic spin Hall effect can be observed when breaking the rotational symmetry of metasurfaces. Moreover, we show that the dielectric metasurfaces can provide great flexibility in the design of novel spin-photonic devices such as spin filter and spin-dependent beam splitter.
Manipulating topological states by imprinting non-collinear spin textures
Streubel, Robert; Han, Luyang; Im, Mi -Young; Kronast, Florian; Rößler, Ulrich K.; Radu, Florin; Abrudan, Radu; Schmidt, Oliver G.; Fischer, Peter; Makarov, Denys
2015-03-05
Topological magnetic states, such as chiral skyrmions, are of great scientific interest and show huge potential for novel spintronics applications, provided their topological charges can be fully controlled. So far skyrmionic textures have been observed in noncentrosymmetric crystalline materials with low symmetry and at low temperatures. We propose theoretically and demonstrate experimentally the design of spin textures with topological charge densities that can be tailored at ambient temperatures. Tuning the interlayer coupling in vertically stacked nanopatterned magnetic heterostructures, such as a model system of a Co/Pd multilayer coupled to Permalloy, the in-plane non-collinear spin texture of one layer can be imprinted into the out-of-plane magnetised material. We observe distinct spin textures, e.g. vortices, magnetic swirls with tunable opening angle, donut states and skyrmion core configurations. We show that applying a small magnetic field, a reliable switching between topologically distinct textures can be achieved at remanence
Manipulating topological states by imprinting non-collinear spin textures
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Streubel, Robert; Han, Luyang; Im, Mi -Young; Kronast, Florian; Rößler, Ulrich K.; Radu, Florin; Abrudan, Radu; Lin, Gungun; Schmidt, Oliver G.; Fischer, Peter; et al
2015-03-05
Topological magnetic states, such as chiral skyrmions, are of great scientific interest and show huge potential for novel spintronics applications, provided their topological charges can be fully controlled. So far skyrmionic textures have been observed in noncentrosymmetric crystalline materials with low symmetry and at low temperatures. We propose theoretically and demonstrate experimentally the design of spin textures with topological charge densities that can be tailored at ambient temperatures. Tuning the interlayer coupling in vertically stacked nanopatterned magnetic heterostructures, such as a model system of a Co/Pd multilayer coupled to Permalloy, the in-plane non-collinear spin texture of one layer can bemore »imprinted into the out-of-plane magnetised material. We observe distinct spin textures, e.g. vortices, magnetic swirls with tunable opening angle, donut states and skyrmion core configurations. We show that applying a small magnetic field, a reliable switching between topologically distinct textures can be achieved at remanence« less
LUBRICATION APPROXIMATION WITH PRESCRIBED NONZERO CONTACT ANGLE
Otto, Felix
LUBRICATION APPROXIMATION WITH PRESCRIBED NONZERO CONTACT ANGLE Felix Otto Department--time existence for a weak solution s(t; x) â?? 0 of the lubrication approximation @ t s + @ x (s @ 3 x s) = 0 in fs will later motivate the way we construct approximate solutions for the lubrication approximation we are going
Imaging properties of supercritical angle fluorescence optics
Enderlein, Jörg
Imaging properties of supercritical angle fluorescence optics J¨org Enderlein,1,4, Ingo Gregor,1.ruckstuhl@pci.uzh.ch 4http://www.joerg-enderlein.de enderlein@physik3.gwdg.de Abstract: In recent years, new optical the detection volume within one wavelength to an interface. For conventional optical systems with high numerical
Azimuthal angle dependence of dijet production in unpolarized hadron scattering
Lu Zhun; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile) and Center of Subatomic Physics, Valparaiso (Chile)
2008-08-01
We study the azimuthal angular dependence of back-to-back dijet production in unpolarized hadron scattering H{sub A}+H{sub B}{yields}J{sub 1}+J{sub 2}+X, arising from the product of two Boer-Mulders functions, which describe the transverse spin distribution of quarks inside an unpolarized hadron. We find that when the dijet is of two identical quarks (J{sub q}+J{sub q}) or a quark-antiquark pair (J{sub q}+J{sub q}), there is a cos{delta}{phi} angular dependence of the dijet, with {delta}{phi}={phi}{sub 1}-{phi}{sub 2}, and {phi}{sub 1} and {phi}{sub 2} are the azimuthal angles of the two individual jets. In the case of J{sub q}+J{sub q} production, we find that there is a color factor enhancement in the gluonic cross section, compared with the result from the standard generalized parton model. We estimate the cos{delta}{phi} asymmetry of dijet production at RHIC, showing that the color factor enhancement in the angular dependence of J{sub q}+J{sub q} production will reverse the sign of the asymmetry.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Fanelli, Cristiano V.
2015-10-06
Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The WACS polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of ?Pcm = 70°. The longitudinal transfer KLL, measured to be 0.645 ± 0.059 ± 0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton.more »However, the observed value is ~3 times larger than predicted by the GPD-based calculations, which indicates a significant unknown contribution to the scattering amplitude.« less
Geometric phase for collinear conical intersections. I. Geometric phase angle and vector potentials
Li Xuan [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019 (United States); Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); Brue, Daniel A.; Blandon, Juan D.; Parker, Gregory A. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019 (United States); Kendrick, Brian K. [Theoretical Division (T-1, MS B268), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2011-02-14
We present a method for properly treating collinear conical intersections in triatomic systems. The general vector potential (gauge theory) approach for including the geometric phase effects associated with collinear conical intersections in hyperspherical coordinates is presented. The current study develops an introductory method in the treatment of collinear conical intersections by using the phase angle method. The geometric phase angle, {eta}, in terms of purely internal coordinates is derived using the example of a spin-aligned quartet lithium triatomic system. A numerical fit and thus an analytical form for the associated vector potentials are explicitly derived for this triatomic A{sub 3} system. The application of this methodology to AB{sub 2} and ABC systems is also discussed.
Coherent heteronuclear spin dynamics in an ultracold spin-1 mixture
Li, Xiaoke; He, Xiaodong; Wang, Fudong; Guo, Mingyang; Xu, Zhi-Fang; Zhang, Shizhong; Wang, Dajun
2015-01-01
We report the observation of coherent heteronuclear spin dynamics driven by inter-species spin-spin interaction in an ultracold spinor mixture, which manifests as periodical and well correlated spin oscillations between two atomic species. In particular, we investigate the magnetic field dependence of the oscillations and find a resonance behavior which depends on {\\em both} the linear and quadratic Zeeman effects and the spin-dependent interaction. We also demonstrate a unique knob for controlling the spin dynamics in the spinor mixture with species-dependent vector light shifts. Our finds are in agreement with theoretical simulations without any fitting parameters.
Angle Coverage in Wireless Sensor Networks Chow Kit Yee
Tam, Vincent W. L.
. We study the scheduling problem to monitor a target continuously with full angle coverage. Several
Sandia Energy - Spontaneous Coherence and Spin Texture
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Spontaneous Coherence and Spin Texture Home Energy Research EFRCs Solid-State Lighting Science EFRC Spontaneous Coherence and Spin Texture Spontaneous Coherence and Spin...
Marie-Anne Bouchiat; Claude Bouchiat
2010-11-05
We derive the general formula giving the Berry phase for an arbitrary spin, having both magnetic-dipole and electric-quadrupole couplings with external time-dependent fields. We assume that the effective E and B fields remain orthogonal during the quantum cycles. This mild restriction has many advantages. It provides simple symmetries leading to selection rules and the Hamiltonian-parameter and density-matrix spaces coincide for S=1. This implies the identity of the Berry and Aharonov-Anandan phases, which is lost for S>1. We have found that new features of Berry phases emerge for integer spins>2. We provide explicit numerical results of Berry phases for S=2,3,4. We give a precise analysis of the non-adiabatic corrections. The accuracy for satisfying adiabaticity is greatly improved if one chooses for the time derivatives of the parameters a time-dependence having a Blackman pulse shape. This has the effect of taming the non-adiabatic oscillation corrections which could be generated by a linear ramping. For realistic experimental conditions, the non-adibatic corrections can be kept reversal of the angular velocity can be cancelled exactly if the quadrupole to dipole coupling ratio takes a "magic" value. The even ones are cancelled by subtraction of the phases relative to opposite velocities. As a possible application of the results of this paper we suggest a route to holonomic entanglement of N non-correlated 1/2-spins by performing adiabatic cycles governed by a Hamiltonian which is a non-linear function of the total spin operator S defined as the sum of the N spin operators. The case N=4 and Sz=1 is treated explicitly and maximum entanglement is achieved.
Analytical formula for numerical evaluations of the Wigner rotation matrices at high spins
Tajima, Naoki
2015-01-01
The Wigner d function, which is the essential part of an irreducible representation of SU(2) and SO(3) parameterized with Euler angles, has been know to suffer from a serious numerical errors at high spins, if it is calculated by means of the Wigner formula as a polynomial of cos and sin of half of the second Euler angle. This paper shows a way to avoid this problem by expressing the d functions as the Fourier series of the half angle. A precise numerical table of the coefficients of the series is obtainable from a web site.
Analytical formula for numerical evaluations of the Wigner rotation matrices at high spins
Naoki Tajima
2015-01-26
The Wigner d function, which is the essential part of an irreducible representation of SU(2) and SO(3) parameterized with Euler angles, has been know to suffer from a serious numerical errors at high spins, if it is calculated by means of the Wigner formula as a polynomial of cos and sin of half of the second Euler angle. This paper shows a way to avoid this problem by expressing the d functions as the Fourier series of the half angle. A precise numerical table of the coefficients of the series is obtainable from a web site.
The contact angle in inviscid fluid mechanics
P N Shankar; R Kidambi
2005-08-17
We show that in general, the specification of a contact angle condition at the contact line in inviscid fluid motions is incompatible with the classical field equations and boundary conditions generally applicable to them. The limited conditions under which such a specification is permissible are derived; however, these include cases where the static meniscus is not flat. In view of this situation, the status of the many `solutions' in the literature which prescribe a contact angle in potential flows comes into question. We suggest that these solutions which attempt to incorporate a phenomenological, but incompatible, condition are in some, imprecise sense `weak-type solutions'; they satisfy or are likely to satisfy, at least in the limit, the governing equations and boundary conditions everywhere except in the neighbourhood of the contact line. We discuss the implications of the result for the analysis of inviscid flows with free surfaces.
Miller, Jan D; Hupka, Jan; Aranowski, Robert
2012-11-20
A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.
Performance studies of the new stereoscopic Sum-Trigger-II of MAGIC after one year of operation
Dazzi, F; Lopez, M; Nakajima, D; Garcia, J Rodriguez; Schweizer, T
2015-01-01
MAGIC is a stereoscopic system of two Imaging Air Cherenkov Telescopes (IACTs) located at La Palma (Canary Islands, Spain) and working in the field of very high energy gamma-ray astronomy. It makes use of a traditional digital trigger with an energy threshold of around 55 GeV. A novel trigger strategy, based on the analogue sum of signals from partially overlapped patches of pixels, leads to a lower threshold. In 2008, this principle was proven by the detection of the Crab Pulsar at 25 GeV by MAGIC in single telescope operation. During Winter 2013/14, a new system, based on this concept, was implemented for stereoscopic observations after several years of development. In this contribution the strategy of the operative stereoscopic trigger system, as well as the first performance studies, are presented. Finally, some possible future improvements to further reduce the energy threshold of this trigger are addressed.
Wide Angle Effects in Galaxy Surveys
Yoo, Jaiyul
2013-01-01
Current and future galaxy surveys cover a large fraction of the entire sky with a significant redshift range, and the recent theoretical development shows that general relativistic effects are present in galaxy clustering on very large scales. This trend has renewed interest in the wide angle effect in galaxy clustering measurements, in which the distant-observer approximation is often adopted. Using the full wide-angle formula for computing the redshift-space correlation function, we show that compared to the sample variance, the deviation in the redshift-space correlation function from the simple Kaiser formula with the distant-observer approximation is negligible in the SDSS and is completely irrelevant in future galaxy surveys such as Euclid and the BigBOSS, if the theoretical prediction from the Kaiser formula is averaged over the survey volume and the non-uniform distribution of cosine angle between the line-of-sight and the pair separation directions is properly considered. We also find small correctio...
Spin Precession and Quantum Vacuum
F. Kheirandish; M. Amooshahi
2005-09-18
The effect of quantum vacuum on spin precession is investigated. The radiation reaction is obtained and the time of spin flip (up state to down state) or spontaneous decay, is calculated.
Spin Systems and Computational Complexity
Daniel Gottesman
2009-11-30
I give a very brief non-technical introduction to the intersection of the fields of spin systems and computational complexity. The focus is on spin glasses and their relationship to NP-complete problems.
Palacio, J; Acosta, M Vazquez; Colin, P; Maggio, C; Rico, J
2015-01-01
We present preliminary results on Dark Matter searches from observations of the Perseus galaxy cluster with the MAGIC Telescopes. MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. Galaxy clusters are the largest known gravitationally bound structures in the Universe, with masses of ~10^15 Solar masses. There is strong evidence that galaxy clusters are Dark Matter dominated objects, and therefore promising targets for Dark Matter searches, particularly for decay signals. MAGIC has taken almost 300 hours of data on the Perseus Cluster between 2009 and 2015, the deepest observational campaign on any galaxy cluster performed so far in the very high energy range of the electromagnetic spectrum. We analyze here a small sample of this data and search for signs of dark matter in the mass range between 100 GeV and 20 TeV. We apply a likelihood analysis optimized for the spectral and morphological features expected in the dark matter decay signals. This i...
Pair Creation at Large Inherent Angles
Chen, P.; Tauchi, T.; Schroeder, D.V.; /SLAC
2007-04-25
In the next-generation linear colliders, the low-energy e{sup +}e{sup -} pairs created during the collision of high-energy e{sup +}e{sup -} beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al[1]. At energies where the beamstrahlung parameter {Upsilon} lies approximately in the range 0.6 {approx}< {Upsilon} {approx}< 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen[2]. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. One source of transverse momentum is from the kick by the field of the oncoming beam which results in an outcoming angle {theta} {proportional_to} 1/{radical}x, where x is the fractional energy of the particle relative to the initial beam particle energy[2,3]. As was shown in Ref. 131, there in fact exists an energy threshold for the coherent pairs, where x{sub th} {approx}> 1/2{Upsilon}. Thus within a tolerable exiting angle, there exists an upper limit for {Upsilon} where all coherent pairs would leave the detector through the exhaust port[4]. A somewhat different analysis has been done by Schroeder[5]. In the next generation of linear colliders, as it occurs, the coherent pairs can be exponentially suppressed[2] by properly choosing the {Upsilon}({approx}< 0.6). When this is achieved, the incoherent pairs becomes dominant. Since the central issue is the transverse momentum for particles with large angles, we notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. This issue was first studied in Ref. [1]. In this paper we reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer[6].
Morris, William
2012-01-01
4 mm (outside diameter) zirconia rotors. The magic angle was4 mm (outside diameter) zirconia rotors. The magic angle was4 mm (outside diameter) zirconia rotors. The magic angle was
Spin Transport in Semiconductor heterostructures
Domnita Catalina Marinescu
2011-02-22
The focus of the research performed under this grant has been the investigation of spin transport in magnetic semiconductor heterostructures. The interest in these systems is motivated both by their intriguing physical properties, as the physical embodiment of a spin-polarized Fermi liquid, as well as by their potential applications as spintronics devices. In our work we have analyzed several different problems that affect the spin dynamics in single and bi-layer spin-polarized two-dimensional (2D) systems. The topics of interests ranged from the fundamental aspects of the electron-electron interactions, to collective spin and charge density excitations and spin transport in the presence of the spin-orbit coupling. The common denominator of these subjects is the impact at the macroscopic scale of the spin-dependent electron-electron interaction, which plays a much more subtle role than in unpolarized electron systems. Our calculations of several measurable parameters, such as the excitation frequencies of magneto-plasma modes, the spin mass, and the spin transresistivity, propose realistic theoretical estimates of the opposite-spin many-body effects, in particular opposite-spin correlations, that can be directly connected with experimental measurements.
Microwave generation by spin Hall nanooscillators with nanopatterned spin injector
Zholud, A., E-mail: azholud@emory.edu; Urazhdin, S. [Department of Physics, Emory University, Atlanta, Georgia 30322 (United States)
2014-09-15
We experimentally study spin Hall nano-oscillators based on Pt/ferromagnet bilayers with nanopatterned Pt spin injection layer. We demonstrate that both the spectral characteristics and the electrical current requirements can be simultaneously improved by reducing the spin injection area. Moreover, devices with nanopatterned Pt spin injector exhibit microwave generation over a wide temperature range that extends to room temperature. Studies of devices with additional Pt spacers under the device electrodes show that the oscillation characteristics are affected not only by the spin injection geometry but also by the effects of Pt/ferromagnet interface on the dynamical properties of the ferromagnet.
Yelena Prok
2010-05-01
Inelastic scattering using polarized nucleon targets and polarized charged lepton beams allows the extraction of double and single spin asymmetries that provide information about the helicity structure of the nucleon. A program designed to study such processes at low and intermediate $Q^2$ for the proton and deuteron has been pursued by the CLAS Collaboration at Jefferson Lab since 1998. Our inclusive data with high statistical precision and extensive kinematic coverage allow us to better constrain the polarized parton distributions and to accurately determine various moments of spin structure function $g_1$ as a function of $Q^2$. The latest results will be shown, illustrating our contribution to the world data, with comparisons of the data with NLO global fits, phenomenological models, chiral perturbation theory and the GDH and Bjorken sum rules. The semi-inclusive measurements of single and double spin asymmetries for charged and neutral pions are also show, indicating the importance of the orbital motion of quarks in understanding the spin structure of the nucleon.
Spin Operators for Massive Particles
Taeseung Choi; Sam Young Cho
2014-10-02
How to define a proper relativistic spin operator, as a long-standing problem, has by now become a central task for providing proper concepts and applications of spin in relativistic and non-relativistic quantum mechanics as well as solving emergent inconsistencies in rapidly developing research areas. We rigorously {\\it derive} a relativistic spin operator for an arbitrary spin massive particle on the two requirements that a proper spin operator should satisfy (i) the $\\mathfrak{su}(2)$ algebra and (ii) the Lorentz-transformation properties as a second-rank spin tensor. These requirements lead to two spin operators, properly giving the second Casimir invariant operator in the Poincar\\'e (inhomogeneous Lorentz) group, that provide the two inequivalent representations of Poincar\\'e group. We find that the two inequivalent representations are the left-handed and the right-handed representations. Each of the two spin operators generates a Wigner little group whose representation space is composed of spin-$s$ spin states. In the case that the Poincar\\'e group is extended by parity, only nonchiral $(s,s)$ representations and direct-sum $(s,s') \\oplus (s',s)$ representations are allowed. In the $(1/2,0)\\oplus (0,1/2)$ representation, we redrive the covariant Dirac equation by using the covariant parity operator defined by the two spin operators. This derivation deepens our understanding how the Dirac equation describes the spin-$1/2$ massive relativistic particle successfully. We have also discussed some important properties of our relativistic spin operators with arbitrary spin.
Enhancement of nonlocal spin-valve signal using spin accumulation in local spin-valve configuration
Otani, Yoshichika
because of additional spin functionalities. Recently, a class of spintronic devices, such as spin battery properties is essential to realizing such spintronic devices. Vertical structures are suitable to observe to keep spin information. Such lateral struc- tures can be applied to develop multiterminal spintronic de
SMB, Small Angle X-Ray Scattering
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-Throughput Analysis of Protein1-0845*RV 14800Small Angle X-Ray Scattering Home Â»
Anomalous pairing vibration in neutron-rich Sn isotopes beyond the N=82 magic number
Hirotaka Shimoyama; Masayuki Matsuo
2011-06-09
Two-neutron transfer associated with the pair correlation in superfluid neutron-rich nuclei is studied with focus on low-lying $0^+$ states in Sn isotopes beyond the N=82 magic number. We describe microscopically the two-neutron addition and removal transitions by means of the Skyrme-Hartree-Fock-Bogoliubov mean-field model and the continuum quasiparticle random phase approximation formulated in the coordinate space representation. It is found that the pair transfer strength for the transitions between the ground states becomes significantly large for the isotopes with $A \\ge 140$, reflecting very small neutron separation energy and long tails of the weakly bound $3p$ orbits. In $^{132-140}$Sn, a peculiar feature of the pair transfer is seen in transitions to low-lying excited $0^+$ states. They can be regarded as a novel kind of pair vibrational mode which is characterized by an anomalously long tail of the transition density extending to far outside of the nuclear surface, and a large strength comparable to that of the ground-state transitions. The presence of the weakly bound neutron orbits plays a central role for these anomalous behaviors.
Oleg Achakovskiy; Sergei Kamerdzhiev; Victor Tselyaev; Mikhail Shitov
2015-11-03
The neutron capture cross sections and average radiative widths of neutron resonances for two double-magic nuclei 132Sn and 208Pb have been calculated using the microscopic photon strength functions, which were obtained within the microscopic self-consistent version of the extended theory of finite Fermi systems in the time blocking approximation. For the first time, the microscopic PSFs have been obtained within the fully self-consistent approach with exact accounting for the single particle continuum (for 208Pb). The approach includes phonon coupling effects in addition to the standard RPA approach. The known Skyrme force has been used. The calculations of nuclear reaction characteristics have been performed with the EMPIRE 3.1 nuclear reaction code. Here, three nuclear level density (NLD) models have been used: the so-called phenomenological GSM, the EMPIRE specific (or Enhanced GSM) and the microscopical combinatorial HFB NLD models. For both considered characteristics we found a significant disagreement between the results obtained with the GSM and HFB NLD models. For 208Pb, a reasonable agreement has been found with systematics for the average radiative widths values with HFB NLD and with the experimental data for the HFB NLD average resonance spacing D0, while for these two quantities the differences between the values obtained with GSM and HFB NLD are of several orders of magnitude. The discrepancies between the results with the phenomenological EGLO PSF and microscopic RPA or TBA are much less for the same NLD model.
Optimized dark matter searches in deep observations of Segue 1 with MAGIC
Aleksi?, J.; Blanch, O.; Ansoldi, S.; Antonelli, L.A.; Bonnoli, G.; Antoranz, P.; Babic, A.; Bangale, P.; De Almeida, U. Barres; Bock, R.K.; Borracci, F.; Barrio, J.A.; Bonnefoy, S.; González, J. Becerra; Berger, K.; Bednarek, W.; Bernardini, E.; Biland, A.; Bretz, T.; Carmona, E. E-mail: jrico@ifae; and others
2014-02-01
We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ? 500 GeV dark matter particle annihilating into ?{sup +}?{sup ?}, and is of order (?{sub ann}v) ? 1.2 × 10{sup ?24} cm{sup 3} s{sup ?1} — a factor ? 40 above the (?{sub ann}v) ? thermal value.
Small Angle X-ray Scattering (SAXS) Laboratory Learning Experiences
Meagher, Mary
.A. & Svergun D.I. (1987). Structure Analysis by Small-Angle X-Ray and Neutron Scattering. NY: Plenum PressSmall Angle X-ray Scattering (SAXS) Laboratory Learning Experiences o - Use of small angle X-ray scattering instrumentation o - Programs that you will use SAXS (BRUKER AXS) PRIMUS (Konarev, Volkov, Koch
Tetrahedral Mesh Generation with Good Dihedral Angles Using Point Lattices
O'Brien, James F.
be of good quality; in partic- ular there should be no plane or dihedral angle close to 0 or 180 degreesTetrahedral Mesh Generation with Good Dihedral Angles Using Point Lattices by FrancÂ¸ois Labelle B Tetrahedral Mesh Generation with Good Dihedral Angles Using Point Lattices by FrancÂ¸ois Labelle Doctor
Medium energy pitch angle distribution during substorm injected electron clouds
Bergen, Universitetet i
Medium energy pitch angle distribution during substorm injected electron clouds A. AÂ° snes,1 J, N. Ã?stgaard, and M. Thomsen (2005), Medium energy pitch angle distribution during substorm injected to obtain pitch angle resolved electron distribution data for measurements at energies 10 eV to 47 keV. [3
Prestgard, Megan C.; Tiwari, Ashutosh
2014-03-24
The inverse spin Hall effect (ISHE) is a newly discovered, quantum mechanical phenomenon where an applied spin current results in the generation of an electrical voltage in the transverse direction. It is anticipated that the ISHE can provide a more simple way of measuring spin currents in spintronic devices. The ISHE was first observed in noble metals that exhibit strong spin-orbit coupling. However, recently, the ISHE has been detected in conventional semiconductors (such as Si and Ge), which possess weak spin-orbit coupling. This suggests that large-spin orbit coupling is not a requirement for observing the ISHE. In this paper, we are reporting the observation of the ISHE in an alternative semiconductor material, zinc oxide (ZnO) using all-electrical means. In our study, we found that when a spin-polarized current is injected into the ZnO film from a NiFe ferromagnetic injector via an MgO tunnel barrier layer, a voltage transverse to both the direction of the current as well as its spin-polarization is generated in the ZnO layer. The polarity of this voltage signal was found to flip on reversing the direction of the injected current as well as on reversing the polarization of the current, consistent with the predictions of the ISHE process. Through careful analysis of the ISHE data, we determined a spin-Hall angle of approximately 1.651 × 10{sup ?2} for ZnO, which is two orders of magnitude higher than that of silicon. Observation of a detectable room-temperature ISHE signal in ZnO via electrical injection and detection is a groundbreaking step that opens a path towards achieving transparent spin detectors for next-generation spintronic device technology.
Xiang-Song Chen; Wei-Min Sun; Fan Wang; T. Goldman
2011-05-31
We analyze the problem of spin decomposition for an interacting system from a natural perspective of constructing angular momentum eigenstates. We split, from the total angular momentum operator, a proper part which can be separately conserved for a stationary state. This part commutes with the total Hamiltonian and thus specifies the quantum angular momentum. We first show how this can be done in a gauge-dependent way, by seeking a specific gauge in which part of the total angular momentum operator vanishes identically. We then construct a gauge-invariant operator with the desired property. Our analysis clarifies what is the most pertinent choice among the various proposals for decomposing the nucleon spin. A similar analysis is performed for extracting a proper part from the total Hamiltonian to construct energy eigenstates.
Wu, C. N.; Hung, H. Y.; Lin, H. Y.; Lin, P. H.; Kwo, J. E-mail: raynien@phys.nthu.edu.tw; Lin, Y. H.; Fanchiang, Y. T.; Hong, M. E-mail: raynien@phys.nthu.edu.tw; Lin, J. G.; Lee, S. F.
2015-05-07
Spin pumping effect in Bi{sub 2}Se{sub 3}/Fe{sub 3}Si and Fe/Bi{sub 2}Te{sub 3} heterostructures was studied. High quality films of Bi{sub 2}Se{sub 3}(001) on ferromagnetic Fe{sub 3}Si(111) layer and Fe(111) films on Bi{sub 2}Te{sub 3}(001) layer were grown epitaxially by molecular beam epitaxy. Using a microwave cavity source, large voltages due to the Inverse Spin Hall Effect (V{sub ISHE}) were detected in Bi{sub 2}Se{sub 3}(001)/Fe{sub 3}Si(111) bi-layer at room temperature. V{sub ISHE} of up to 63.4?±?4.0??V at 100 mW microwave power (P{sub MW}) was observed. In addition, Fe(111)/Bi{sub 2}Te{sub 3}(001) bi-layer also showed a large V{sub ISHE} of 3.0?±?0.1??V at P{sub MW} of 25 mW. V{sub ISHE} of both structures showed microwave linear power dependence in accordance with the theoretical model of spin pumping. The spin Hall angle was calculated to be 0.0053?±?0.002 in Bi{sub 2}Se{sub 3} and was estimated to be 0.0068?±?0.003 in Bi{sub 2}Te{sub 3}. The charge current density (J{sub c}) of Bi{sub 2}Se{sub 3}/Fe{sub 3}Si and Fe/Bi{sub 2}Te{sub 3} structures are comparable and are about 2–5 times higher than the Fe{sub 3}Si/normal metal and Fe{sub 3}Si/GaAs results. The significant enhancement of spin current in topological insulator/ferromagnetic metal (TI/FM) and FM/TI bilayers is attributed to strong spin-orbit coupling inherent of TIs and demonstrates the high potential of exploiting TI-based structures for spintronic applications.
Impedance Scaling for Small Angle Transitions
Stupakov, G.; Bane, Karl; /SLAC; Zagorodnov, I.; /DESY; ,
2010-10-27
Based on the parabolic equation approach to Maxwell's equations we have derived scaling properties of the high frequency impedance/short bunch wakefields of structures. For the special case of small angle transitions we have shown the scaling properties are valid for all frequencies. Using these scaling properties one can greatly reduce the calculation time of the wakefield/impedance of long, small angle, beam pipe transitions, like one often finds in insertion regions of storage rings. We have tested the scaling with wakefield simulations of 2D and 3D models of such transitions, and found that the scaling works well. In modern ring-based light sources one often finds insertion devices having extremely small vertical apertures (on the order of millimeters) to allow for maximal undulator fields reaching the beam. Such insertion devices require that there be beam pipe transitions from these small apertures to the larger cross-sections (normally on the order of centimeters) found in the rest of the ring. The fact that there may be many such transitions, and that these transitions introduce beam pipe discontinuities very close to the beam path, means that their impedance will be large and, in fact, may dominate the impedance budget of the entire ring. To reduce their impact on impedance, the transitions are normally tapered gradually over a long distance. The accurate calculation of the impedance or wakefield of these long transitions, which are typically 3D objects (i.e. they do not have cylindrical symmetry), can be quite a challenging numerical task. In this report we present a method of obtaining the impedance of a long, small angle transition from the calculation of a scaled, shorter one. Normally, the actual calculation is obtained from a time domain simulation of the wakefield in the structure, where the impedance can be obtained by performing a Fourier transform. We shall see that the scaled calculation reduces the computer time and memory requirements significantly, especially for 3D problems, and can make the difference between being able to solve a problem or not. The method is based on the parabolic equation approach to solving Maxwell's equation developed in Refs. [1, 2].
The effect of knee separation and backrest angle on lumbar lordosis angle in various seated postures
Bolen, Bradley Kyle
1999-01-01
.08, 20.32, and 35.56 cm) and three different angles of backrest inclination (90, 105, and 120-deg). Descriptive statistics and one-way ANOVA were used to evaluate the results. Tukey's test was used to compare significant differences among means...
Clouds, Precipitation, and Marine Boundary Layer Structure during the MAGIC Field Campaign
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhou, Xiaoli; Kollias, Pavlos; Lewis, Ernie R.
2015-03-01
The recent ship-based MAGIC (Marine ARM GCSS Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds) field campaign with the marine-capable Second ARM Mobile Facility (AMF2) deployed on the Horizon Lines cargo container M/V Spirit provided nearly 200 days of intraseasonal high-resolution observations of clouds, precipitation, and marine boundary layer (MBL) structure on multiple legs between Los Angeles, California, and Honolulu, Hawaii. During the deployment, MBL clouds exhibited a much higher frequency of occurrence than other cloud types and occurred more often in the warm season than in the cold season. MBL clouds demonstrated a propensity to produce precipitation, which often evaporatedmore »before reaching the ocean surface. The formation of stratocumulus is strongly correlated to a shallow MBL with a strong inversion and a weak transition, while cumulus formation is associated with a much weaker inversion and stronger transition. The estimated inversion strength is shown to depend seasonally on the potential temperature at 700 hPa. The location of the commencement of systematic MBL decoupling always occurred eastward of the locations of cloud breakup, and the systematic decoupling showed a strong moisture stratification. The entrainment of the dry warm air above the inversion appears to be the dominant factor triggering the systematic decoupling, while surface latent heat flux, precipitation, and diurnal circulation did not play major roles. MBL clouds broke up over a short spatial region due to the changes in the synoptic conditions, implying that in real atmospheric conditions the MBL clouds do not have enough time to evolve as in the idealized models. (auth)« less
Clouds, Precipitation, and Marine Boundary Layer Structure during the MAGIC Field Campaign
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhou, Xiaoli [McGill Univ., Montreal, Quebec (Canada); Dept. of Atmospheric and Oceanic Sciences; Kollias, Pavlos [McGill Univ., Montreal, Quebec (Canada); Dept. of Atmospheric and Oceanic Sciences; Lewis, Ernie R. [Brookhaven National Lab., Upton, NY (United States). Biological, Environmental, and Climate Sciences Dept.
2015-03-01
The recent ship-based MAGIC (Marine ARM GCSS Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds) field campaign with the marine-capable Second ARM Mobile Facility (AMF2) deployed on the Horizon Lines cargo container M/V Spirit provided nearly 200 days of intraseasonal high-resolution observations of clouds, precipitation, and marine boundary layer (MBL) structure on multiple legs between Los Angeles, California, and Honolulu, Hawaii. During the deployment, MBL clouds exhibited a much higher frequency of occurrence than other cloud types and occurred more often in the warm season than in the cold season. MBL clouds demonstrated a propensity to produce precipitation, which often evaporated before reaching the ocean surface. The formation of stratocumulus is strongly correlated to a shallow MBL with a strong inversion and a weak transition, while cumulus formation is associated with a much weaker inversion and stronger transition. The estimated inversion strength is shown to depend seasonally on the potential temperature at 700 hPa. The location of the commencement of systematic MBL decoupling always occurred eastward of the locations of cloud breakup, and the systematic decoupling showed a strong moisture stratification. The entrainment of the dry warm air above the inversion appears to be the dominant factor triggering the systematic decoupling, while surface latent heat flux, precipitation, and diurnal circulation did not play major roles. MBL clouds broke up over a short spatial region due to the changes in the synoptic conditions, implying that in real atmospheric conditions the MBL clouds do not have enough time to evolve as in the idealized models. (auth)
Multifrequency spin resonance in diamond
Childress, Lilian; McIntyre, Jean
2010-09-15
Magnetic resonance techniques provide a powerful tool for controlling spin systems, with applications ranging from quantum information processing to medical imaging. Nevertheless, the behavior of a spin system under strong excitation remains a rich dynamical problem. In this paper, we examine spin resonance of the nitrogen-vacancy center in diamond under conditions outside the regime where the usual rotating-wave approximation applies, focusing on effects of multifrequency excitation and excitation with orientation parallel to the spin quantization axis. Strong-field phenomena such as multiphoton transitions and coherent destruction of tunneling are observed in the spectra and analyzed via numerical and analytic theory. In addition to illustrating the response of a spin system to strong multifrequency excitation, these observations may inform techniques for manipulating electron-nuclear spin quantum registers.
Inductance due to spin current
Chen, Wei
2014-03-21
The inductance of spintronic devices that transport charge neutral spin currents is discussed. It is known that in a media that contains charge neutral spins, a time-varying electric field induces a spin current. We show that since the spin current itself produces an electric field, this implies existence of inductance and electromotive force when the spin current changes with time. The relations between the electromotive force and the corresponding flux, which is a vector calculated by the cross product of electric field and the trajectory of the device, are clarified. The relativistic origin generally renders an extremely small inductance, which indicates the advantage of spin current in building low inductance devices. The same argument also explains the inductance due to electric dipole current and applies to physical dipoles consist of polarized bound charges.
Feedback control of spin systems
Claudio Altafini
2006-01-03
The feedback stabilization problem for ensembles of coupled spin 1/2 systems is discussed from a control theoretic perspective. The noninvasive nature of the bulk measurement allows for a fully unitary and deterministic closed loop. The Lyapunov-based feedback design presented does not require spins that are selectively addressable. With this method, it is possible to obtain control inputs also for difficult tasks, like suppressing undesired couplings in identical spin systems.
Heat generation by electronic current in a quantum dot spin-valve
Chi, Feng; Sun, Lian-Liang; Guo, Yu
2014-10-28
Electric-current-induced heat generation in an interacting single-level quantum dot connected to ferromagnetic leads with noncollinear magnetizations is theoretically investigated. We find that when the two leads' spin polarization rates are identical and much smaller than unit, the magnitude of the heat generation is almost monotonously enhanced as the angle between the leads' magnetic moments is varied from zero to ?, while the magnitude of the electric current is continuously suppressed. Moreover, the properties of the heat generation depend on the lead's spin polarization rate in different ways when the angle is varied. If at least one of the leads' spin polarization rate approaches to unit, the spin-valve effect of the heat generation is identical to that of the electric current. Now the previously found negative differential of the heat generation disappears when the angle approaches to ?. As compared to the current, the heat generation is more sensitive to the system's asymmetry when one of the electrodes is half-metallic in noncollinear configurations.
Ballistic spin-dependent transport of Rashba rings with multi-leads
Huang Guangyao [State Key Laboratory of Optoelectronic Material and Technology and School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Liang Shidong, E-mail: stslsd@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Material and Technology and School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)
2011-05-15
Research Highlights: > Transmission coefficients of each outgoing lead in multi-lead mesoscopic Rashba rings. > Spin polarizations of each outgoing lead in multi-lead mesoscopic Rashba rings. > Resonant and antiresonant conditions of spin polarization in multi-lead Rashba rings. > Symmetries of conductance and spin polarization of symmetric multi-lead Rashba rings. - Abstract: Using the Landauer-Buettiker formula with the transfer matrix technique, we develop a formalism of the ballistic spin-dependent electron transport in the multi-lead Rashba rings. We give analytic formulas of the total conductance G{sub j}, spin-{sigma} conductance g{sub j}{sup {sigma}} and spin polarization P{sub j} of each outgoing lead j, and their resonant and antiresonant conditions. Analytic studying with numerical investigating Rashba rings with several symmetric and asymmetric leads, we find that G{sub j}, g{sub j}{sup {sigma}} and P{sub j} oscillate with the incoming electron energy and the spin-orbit interaction (SOI) strength, and their antiresonances depend on the incoming electron energy, the SOI strength and the outgoing-lead angle with the incoming lead. For the symmetric-lead rings, G{sub j}, g{sub j}{sup {sigma}} and P{sub j} have some symmetries, G{sub j}=G{sub N-j},g{sub j}{sup {sigma}}=g{sub N-j}{sup -{sigma}}, and P{sub j} = -P{sub N-j} for symmetric leads, j and N - j, where the angles between the symmetric outgoing leads j and N - j and the incoming lead are {gamma}{sub N-j} = 2{pi} - {gamma}{sub j}. The spin polarization of the outgoing lead with {gamma}{sub j} = {pi} is exactly zero for even-N-symmetric-lead rings. These symmetries originate from the lead symmetry and time reversal invariance. For asymmetry-lead rings these symmetries vanish.
Demand Response Spinning Reserve Demonstration
2007-01-01
Within 10 Minutes After Sudden Failure Of Two Generators inafter sudden failure of two generators in Texas. SpinningIn contrast, failure of a large generator to provide
Lipscombe, O. J.; Chen, G. F.; Fang, Chen; Perring, T. G.; Abernathy, Douglas L; Christianson, Andrew D; Egami, Takeshi; Wang, Nanlin; Hu, Jiangping; Dai, Pengcheng
2011-01-01
We use neutron scattering to show that spin waves in the iron chalcogenide Fe{sub 1.05}Te display novel dispersion clearly different from both the first principles density functional calculations and recent observations in the related iron pnictide CaFe{sub 2}As{sub 2}. By fitting to a Heisenberg Hamiltonian, we find that although the nearest-neighbor exchange couplings in the two systems are quite different, their next-nearest-neighbor (NNN) couplings are similar. This suggests that superconductivity in the pnictides and chalcogenides share a common magnetic origin that is intimately associated with the NNN magnetic coupling between the irons.
Spin-noise correlations and spin-noise exchange driven by low-field spin-exchange collisions
A. T. Dellis; M. Loulakis; I. K. Kominis
2014-09-28
The physics of spin exchange collisions have fueled several discoveries in fundamental physics and numerous applications in medical imaging and nuclear magnetic resonance. We here report on the experimental observation and theoretical justification of spin-noise exchange, the transfer of spin-noise from one atomic species to another. The signature of spin-noise exchange is an increase of the total spin-noise power at low magnetic fields, on the order of 1 mG, where the two-species spin-noise resonances overlap. The underlying physical mechanism is the two-species spin-noise correlation induced by spin-exchange collisions.
Rotatable spin-polarized electron source for inverse-photoemission experiments
Stolwijk, S. D. Wortelen, H.; Schmidt, A. B.; Donath, M.
2014-01-15
We present a ROtatable Spin-polarized Electron source (ROSE) for the use in spin- and angle-resolved inverse-photoemission (SR-IPE) experiments. A key feature of the ROSE is a variable direction of the transversal electron beam polarization. As a result, the inverse-photoemission experiment becomes sensitive to two orthogonal in-plane polarization directions, and, for nonnormal electron incidence, to the out-of-plane polarization component. We characterize the ROSE and test its performance on the basis of SR-IPE experiments. Measurements on magnetized Ni films on W(110) serve as a reference to demonstrate the variable spin sensitivity. Moreover, investigations of the unoccupied spin-dependent surface electronic structure of Tl/Si(111) highlight the capability to analyze complex phenomena like spin rotations in momentum space. Essentially, the ROSE opens the way to further studies on complex spin-dependent effects in the field of surface magnetism and spin-orbit interaction at surfaces.
Hidden pseudospin and spin symmetries and their origins in atomic nuclei
Haozhao Liang; Jie Meng; Shan-Gui Zhou
2014-11-25
Symmetry plays a fundamental role in physics. The quasi-degeneracy between single-particle orbitals $(n, l, j = l + 1/2)$ and $(n-1, l + 2, j = l + 3/2)$ indicates a hidden symmetry in atomic nuclei, the so-called pseudospin symmetry (PSS). Since the introduction of the concept of PSS in atomic nuclei, there have been comprehensive efforts to understand its origin. Both splittings of spin doublets and pseudospin doublets play critical roles in the evolution of magic numbers in exotic nuclei discovered by modern spectroscopic studies with radioactive ion beam facilities. Since the PSS was recognized as a relativistic symmetry in 1990s, many special features, including the spin symmetry (SS) for anti-nucleon, and many new concepts have been introduced. In the present Review, we focus on the recent progress on the PSS and SS in various systems and potentials, including extensions of the PSS study from stable to exotic nuclei, from non-confining to confining potentials, from local to non-local potentials, from central to tensor potentials, from bound to resonant states, from nucleon to anti-nucleon spectra, from nucleon to hyperon spectra, and from spherical to deformed nuclei. Open issues in this field are also discussed in detail, including the perturbative nature, the supersymmetric representation with similarity renormalization group, and the puzzle of intruder states.
Spin noise spectroscopy of ZnO
Horn, H.; Berski, F.; Hübner, J.; Oestreich, M.; Balocchi, A.; Marie, X.; Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A.
2013-12-04
We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.
Co', G; Anguiano, M; Bernard, R N; Lallena, A M
2015-01-01
We present a model which describes the properties of odd-even nuclei with one nucleon more, or less, with respect to the magic number. In addition to the effects related to the unpaired nucleon, we consider those produced by the excitation of the closed shell core. By using a single particle basis generated with Hartree-Fock calculations, we describe the polarization of the doubly magic-core with Random Phase Approximation collective wave functions. In every step of the calculation, and for all the nuclei considered, we use the same finite-range nucleon-nucleon interaction. We apply our model to the evaluation of electric quadrupole and magnetic dipole moments of odd-even nuclei around oxygen, calcium, zirconium, tin and lead isotopes. Our Random Phase Approximation description of the polarization of the core improves the agreement with experimental data with respect to the predictions of the independent particle model. We compare our results with those obtained in first-order perturbation theory, with those ...
G. Co'; V. De Donno; M. Anguiano; R. N. Bernard; A. M. Lallena
2015-09-08
We present a model which describes the properties of odd-even nuclei with one nucleon more, or less, with respect to the magic number. In addition to the effects related to the unpaired nucleon, we consider those produced by the excitation of the closed shell core. By using a single particle basis generated with Hartree-Fock calculations, we describe the polarization of the doubly magic-core with Random Phase Approximation collective wave functions. In every step of the calculation, and for all the nuclei considered, we use the same finite-range nucleon-nucleon interaction. We apply our model to the evaluation of electric quadrupole and magnetic dipole moments of odd-even nuclei around oxygen, calcium, zirconium, tin and lead isotopes. Our Random Phase Approximation description of the polarization of the core improves the agreement with experimental data with respect to the predictions of the independent particle model. We compare our results with those obtained in first-order perturbation theory, with those produced by Hartree-Fock-Bogolioubov calculations and with those generated within the Landau-Migdal theory of finite Fermi systems. The results of our universal, self-consistent, and parameter free approach have the same quality of those obtained with phenomenological approaches where the various terms of the nucleon-nucleon interaction are adapted to reproduce some specific experimental data. A critical discussion on the validity of the model is presented.
Emission angle distribution and flavor transformation of supernova neutrinos
Wei Liao
2009-06-28
Using moment equations we analyze collective flavor transformation of supernova neutrinos. We study the convergence of moment equations and find that numerical results using a few moment converge quite fast. We study effects of emission angle distribution of neutrinos on neutrino sphere. We study scaling law of the amplitude of neutrino self-interaction Hamiltonian and find that it depends on model of emission angle distribution of neutrinos. Dependence of neutrino oscillation on different models of emission angle distribution is studied.
Recent Development in Proton Spin Physics
Yuan, Feng
2009-01-01
Development in Proton Spin Physics Feng YUAN [8] H. Jackson,investigations. These important physics, together with otherthat the transverse spin physics is playing a very important
The generalized Mackenzie distribution: disorientation angle distributions for arbitrary textures
Mason, J. K.
A general formulation for the disorientation angle distribution function is derived. The derivation employs the hyperspherical harmonic expansion for orientation distributions, and an explicit solution is presented for ...
Identification of high angle structures controlling the geothermal...
Identification of high angle structures controlling the geothermal system at Rye Patch, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper:...
Measurements of integral muon intensity at large zenith angles
A. N. Dmitrieva; D. V. Chernov; R. P. Kokoulin; K. G. Kompaniets; G. Mannocchi; A. A. Petrukhin; O. Saavedra; V. V. Shutenko; D. A. Timashkov; G. Trinchero; I. I. Yashin
2006-11-28
High-statistics data on near-horizontal muons collected with Russian-Italian coordinate detector DECOR are analyzed. Precise measurements of muon angular distributions in zenith angle interval from 60 to 90 degrees have been performed. In total, more than 20 million muons are selected. Dependences of the absolute integral muon intensity on zenith angle for several threshold energies ranging from 1.7 GeV to 7.2 GeV are derived. Results for this region of zenith angles and threshold energies have been obtained for the first time. The dependence of integral intensity on zenith angle and threshold energy is well fitted by a simple analytical formula.
Local Uniqueness for the Fixed Energy Fixed Angle Inverse Problem ...
Abstract. We prove local uniqueness for the inverse problem in obstacle scattering at a fixed energy and fixed incident angle. We consider the inverse problem of ...
Squeezing in Multivariate Spin Systems
Swarnamala Sirsi
2005-09-18
In contrast to the canonically conjugate variates $q$,$p$ representing the position and momentum of a particle in the phase space distributions, the three Cartesian components, $J_{x}$,$J_{y}$, $J_{z}$ of a spin-$j$ system constitute the mutually non-commuting variates in the quasi-probabilistic spin distributions. It can be shown that a univariate spin distribution is never squeezed and one needs to look into either bivariate or trivariate distributions for signatures of squeezing. Several such distributions result if one considers different characteristic functions or moments based on various correspondence rules. As an example, discrete probability distribution for an arbitrary spin-1 assembly is constructed using Wigner-Weyl and Margenau-Hill correspondence rules. It is also shown that a trivariate spin-1 assembly resulting from the exposure of nucleus with non-zero quadrupole moment to combined electric quadrupole field and dipole magnetic field exhibits squeezing in cerain cases.
Superconducting magnetic Wollaston prism for neutron spin encoding
Li, F., E-mail: fankli@indiana.edu; Parnell, S. R.; Wang, T.; Baxter, D. V. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States)] [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Hamilton, W. A. [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)] [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Maranville, B. B. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Semerad, R. [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany)] [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany); Cremer, J. T. [Adelphi Technology Inc., Redwood City, California 94063 (United States)] [Adelphi Technology Inc., Redwood City, California 94063 (United States); Pynn, R. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States) [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)
2014-05-15
A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ?30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ?98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 ?m. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.
Konstantine Zelator
2012-08-01
Let ABC be a triangle with a,b,and c being its three sidelengths. In a 1976 article by Wynne William Wilson in the Mathematical Gazette(see reference[2]), the author showed that angleB is twice angleA, if and only if b^2=a(a+c). We offer our own proof of this result in Proposition1.Using Proposition1 and Lemma2, we establish Proposition 2: Let a,b,c be positive reals. Then a triangle ABC having a,b,c as its sidelengths can be formed if,and onlyif, b^2=a(a+c) and either cintegral triangles, that is; a,b, and c bieng positive integers.In 2002, in a paper published in the Mathematical Gazette(see[2]), author M.N.Deshpande provided two-parameter formulas that describe some integral triangles with (angle)B=2(angle)A. In Result2 in Section5, we offer 3-parameter formulas that describe the entire family of integral triangles ABC with angleA=2angleB. Using Result1, we then parametrically describe the entire family of integral triangles with angle A=2angleB; and with the bisector of angleB also of integral length. This is done in Reult2 in Section6. In Section7, we conclude this article with two closing remarks.
Design, Fabrication and Testing of Angled Fiber Suspension for Electrostatic Actuators
Schubert, Bryan Edward
2011-01-01
carbon nanotubes (CNTs) fabricated on nickel by angled, dc,carbon nanotubes (CNTs) fabricated on nickel by angled, dc,
Aqueous Synthesis of Zinc Blende CdTe/CdS Magic-Core/Thick-Shell
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications TraditionalWithAntiferromagnetic Spins DoApply forAprilAprilTetrahedral
Cell separation using tilted-angle standing surface acoustic waves
Dao, Ming
Cell separation using tilted-angle standing surface acoustic waves Xiaoyun Dinga,1 , Zhangli Pengb for studying cell properties, disease diagnostics, and therapeutics. Cell sorting by acoustic waves offers diagnostics. In this work, we introduce a unique configuration of tilted-angle standing surface acoustic waves
Steiner Minimal Trees, Twist Angles, and the Protein Folding Problem
Smith, J. MacGregor
Steiner Minimal Trees, Twist Angles, and the Protein Folding Problem J. MacGregor Smith, Yunho Jang. These properties should be ultimately useful in the ab ini- tio protein folding prediction. Proteins 2007;66:889 902. VVC 2006 Wiley-Liss, Inc. Key words: Steiner trees; twist angles; protein fold- ing; side chain
Delayed Afterglow Onset Interpreted as Baryon-Poor Viewing Angle
David Eichler
2005-03-24
We have suggested previously that baryons in GRB fireballs infiltrate from the surrounding walls that collimate the fireball. The efficiency $\\epsilon_b$ for generating blast energy can then be angle dependent. Delayed onset of afterglow can be interpreted as being due to a baryon-poor viewing angle.
First Measurements of Spin Correlation Using Semi-leptonic $t\\bar{t}$ Events at ATLAS
Boris Lemmer; for the ATLAS Collaboration
2014-11-20
The top quark decays before it hadronizes. Before its spin state can be changed in a process of strong interaction, it is directly transferred to the top quark decay products. The top quark spin can be deduced by studying angular distributions of the decay products. The Standard Model predicts the top/anti-top quark ($t\\bar{t}$) pairs to have correlated spins. The degree is sensitive to the spin and the production mechanisms of the top quark. Measuring the spin correlation allows to test the predictions. New physics effects can be reflected in deviations from the prediction. The measurement of the spin correlation of $t\\bar{t}$ pairs, produced at the LHC with a center-of-mass energy of $\\sqrt{s} = 7$ TeV and reconstructed with the ATLAS detector, is presented. The dataset corresponds to an integrated luminosity of 4.6 $\\textrm{fb}^{-1}$. $t\\bar{t}$ pairs are reconstructed in the $\\ell$+jets channel using a kinematic likelihood fit offering the identification of light up- and down-type quarks from the $t \\rightarrow bW \\rightarrow bq\\bar{q}'$ decay. The spin correlation is measured via the distribution of the azimuthal angle $\\Delta \\phi$ between two top quark spin analyzers in the laboratory frame. It is expressed as the degree of $t\\bar{t}$ spin correlation predicted by the Standard Model, $f_{\\textrm{SM}}$. The result of $f_{\\textrm{SM}}= 1.12 \\pm 0.11\\,\\text{(stat.)} \\pm 0.22\\,\\text{(syst.)}$ is consistent with the Standard Model prediction of $f_{\\textrm{SM}}= 1.0$.
Putting the Spin on Graphite: Observing the Spins of Impurity...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
such a tube can be used as a nanoscale x-ray detector. With the recent advance of "spintronics" - an area of science and technology which proposes to use the spin of electrons to...
Spin Contamination in Inorganic Chemistry Calculations
Schlegel, H. Bernhard
R EVISED PAG E PR O O FS ia617 Spin Contamination in Inorganic Chemistry Calculations Jason L . In such cases, 0 is said to be spin contaminated owing to incorporation of higher spin state character of IronSulfur ia618 Clusters). It is important to note that while spin-contaminated and broken
RESEARCH PLAN FOR SPIN PHYSICS AT RHIC.
AIDALA, C.; BUNCE, G.; ET AL.
2005-02-01
In this report we present the research plan for the RHIC spin program. The report covers (1) the science of the RHIC spin program in a world-wide context; (2) the collider performance requirements for the RHIC spin program; (3) the detector upgrades required, including timelines; (4) time evolution of the spin program.
Spin-s wave functions with algebraic order Onuttom Narayan and B. Sriram Shastry
California at Santa Cruz, University of
Spin-s wave functions with algebraic order Onuttom Narayan and B. Sriram Shastry Department November 2004) We generalize the Gutzwiller wave function for s= 1 2 spin chains to construct a family of wave functions for all s 1 2. Through numerical simulations, we demonstrate that the spin spin
Spin-current-induced dynamics in ferromagnetic nanopillars of lateral spin-valve structures
Otani, Yoshichika
Spin-current-induced dynamics in ferromagnetic nanopillars of lateral spin-valve structures J 4 February 2009 Under electrical injection, spin accumulation occurs in lateral spin valves in a lateral spin valve while simultaneously sweeping an external magnetic field. We observe changes
Large Spin Accumulation in a Permalloy-Silver Lateral Spin Valve T. Kimura and Y. Otani
Otani, Yoshichika
Large Spin Accumulation in a Permalloy-Silver Lateral Spin Valve T. Kimura and Y. Otani Institute accumulation due to the electrical spin injection has been observed in Permalloy-silver lateral spin-valve structures. The observed resistance change is the largest among the reported metallic lateral spin valves
Switched Control of Electron Nuclear Spin Systems
Navin Khaneja
2007-07-11
In this article, we study control of electron-nuclear spin dynamics at magnetic field strengths where the Larmor frequency of the nucleus is comparable to the hyperfine coupling strength. The quantization axis for the nuclear spin differs from the static B_0 field direction and depends on the state of the electron spin. The quantization axis can be switched by flipping the state of electron spin, allowing for universal control on nuclear spin states. We show that by performing a sequence of flips (each followed by a suitable delay), we can perform any desired rotation on the nuclear spins, which can also be conditioned on the state of the electron spin. These operations, combined with electron spin rotations can be used to synthesize any unitary transformation on the coupled electron-nuclear spin system. We discuss how these methods can be used for design of experiments for transfer of polarization from the electron to the nuclear spins.
Spin Filtering in Storage Rings
N. N. Nikolaev; F. F. Pavlov
2005-12-05
The spin filtering in storage rings is based on the multiple passage of a stored beam through a polarized internal gas target. Apart from the polarization by transmission, a unique geometrical feature of interaction with the target in such a filtering process, pointed out by H.O. Meyer \\cite{Meyer}, is a scattering of stored particles within the beam. A rotation of the spin in the scattering process affects the polarization buildup. We derive here a quantum-mechanical evolution equation for the spin-density matrix of the stored beam which incorporates scattering within the beam. We show how the interplay of transmission and scattering with the beam changes from polarized electrons to polarized protons in the atomic target. After discussions of the FILTEX results on the filtering of stored protons \\cite{FILTEX}, we comment on the strategy of spin filtering of antiprotons for the PAX experiment at GSI FAIR \\cite{PAX-TP}.
Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young; Kim, Dong-Jun; Park, Byong-Guk
2015-01-19
Ta-layer thickness (t{sub Ta}) dependence of the measured DC voltage V from the inverse-spin Hall effect (ISHE) in Ta/CoFeB bilayer structure is experimentally investigated using the ferromagnetic resonance in the TE{sub 011} resonant cavity. The ISHE signals excluding the spin-rectified effect (SRE) were separated from the fitted curve of V against t{sub Ta}. For t{sub Ta}????{sub Ta} (Ta-spin diffusion length?=?2.7?nm), the deviation in ISHE voltage V{sub ISH} between the experimental and theoretical values is significantly increased because of the large SRE contribution, which also results in a large deviation in the spin Hall angle ?{sub SH} (from 10% to 40%). However, when t{sub Ta} ? ?{sub Ta}, the V{sub ISH} values are consistent with theoretical values because the SRE terms become negligible, which subsequently improves the accuracy of the obtained ?{sub SH} within 4% deviation. The results will provide an outline for an accurate estimation of the ?{sub SH} for materials with small ? value, which would be useful for utilizing the spin Hall effect in a 3-terminal spintronic devices in which magnetization can be controlled by in-plane current.
{gamma} spectroscopy around doubly magic {sup 48}Ca by heavy-ion transfer reactions
Leoni, Silvia
2012-10-20
{gamma} spectroscopy of neutron-rich nuclei around {sup 48}Ca is performed by the heavy-ion transfer reaction {sup 48}Ca on {sup 64}Ni at 282 MeV, with the PRISMA-CLARA setup at Legnaro Laboratory. Angular distributions, polarizations and lifetimes analysis probe spin and parities of several excited states, shading lights on their configuration. In the one neutron transfer channels, {sup 49}Ca and {sup 47}Ca, states arising by coupling a single particle to the 3{sup -} phonon of {sup 48}Ca are observed, showing the robustness of nuclear collectivity in rather light systems. The work demonstrates the feasibility of complete in-beam {gamma}-spectroscopy with heavy-ion transfer reactions and provides a method that can be further exploited in the future with heavy targets and radioactive beams.
Probing the Short Range Spin Dependent Interactions by Polarized $^{3}He$ Atom Beams
H. Yan
2014-09-16
Experiments using polarized $^{3}He$ atom beams to search for short range spin dependent forces are proposed. High intensity, high polarization, small beam size $^{3}He$ atom beams have been successfully produced and used in surface science researches. By incorporating background reduction designs as combination shielding by $\\mu$-metal and superconductor and double beam pathes, the precision of spin rotation angle per unit length could be improved by a factor of $\\sim10^{4}$. By this precision, in combination with using a high density and low magnetic susceptibility sample source mass,and reversing one beam path if necessary, sensitivities on three different types of spin dependent interactions could be possibly improved by as much as $\\sim10^{2}$ to $\\sim10^{8}$ over the current experiments at the millimeter range.
Spin transport in lateral spin valves and across a metal- insulator transition in V?O? /
Erekhinsky, Mikhail
2013-01-01
34] E.I. Rashba, Theory of electrical spin injection: Tunnel3.2 qualitative theory of electrical spin injection isIntroduction The basic theory of electrical spin injection
Spin-dependent boundary resistance in the lateral spin-valve structure T. Kimura,a)
Otani, Yoshichika
such as a spin transistor,3 spin battery,4 etc. However, it has been difficult to detect spin-dependent signals 1(a) and 1(b) show scanning-electron-microscope (SEM) images of the final device. First, we
Nonvanishing spin Hall currents in disordered spin-orbit coupling systems
Nomura, K.; Sinova, Jairo; Jungwirth, T.; Niu, Q.; MacDonald, A. H.
2005-01-01
Spin-orbit coupling-induced spin Hall currents are generic in metals and doped semiconductors. It has recently been argued that the spin Hall conductivity can be dominated by an intrinsic contribution that follows from ...
SU-E-I-56: Scan Angle Reduction for a Limited-Angle Intrafraction Verification (LIVE) System
Ren, L; Zhang, Y; Yin, F [Duke University Medical Center, Durham, NC (United States)
2014-06-01
Purpose: To develop a novel adaptive reconstruction strategy to further reduce the scanning angle required by the limited-angle intrafraction verification (LIVE) system for intrafraction verification. Methods: LIVE acquires limited angle MV projections from the exit fluence of the arc treatment beam or during gantry rotation between static beams. Orthogonal limited-angle kV projections are also acquired simultaneously to provide additional information. LIVE considers the on-board 4D-CBCT images as a deformation of the prior 4D-CT images, and solves the deformation field based on deformation models and data fidelity constraint. LIVE reaches a checkpoint after a limited-angle scan, and reconstructs 4D-CBCT for intrafraction verification at the checkpoint. In adaptive reconstruction strategy, a larger scanning angle of 30° is used for the first checkpoint, and smaller scanning angles of 15° are used for subsequent checkpoints. The onboard images reconstructed at the previous adjacent checkpoint are used as the prior images for reconstruction at the current checkpoint. As the algorithm only needs to reconstruct the small deformation occurred between adjacent checkpoints, projections from a smaller scan angle provide enough information for the reconstruction. XCAT was used to simulate tumor motion baseline drift of 2mm along sup-inf direction at every subsequent checkpoint, which are 15° apart. Adaptive reconstruction strategy was used to reconstruct the images at each checkpoint using orthogonal 15° kV and MV projections. Results: Results showed that LIVE reconstructed the tumor volumes accurately using orthogonal 15° kV-MV projections. Volume percentage differences (VPDs) were within 5% and center of mass shifts (COMS) were within 1mm for reconstruction at all checkpoints. Conclusion: It's feasible to use an adaptive reconstruction strategy to further reduce the scan angle needed by LIVE to allow faster and more frequent intrafraction verification to minimize the treatment errors in lung cancer treatments. Grant from Varian Medical System.
A bulk-flow model of angled injection Lomakin bearings
Soulas, Thomas Antoine Theo
2001-01-01
A bulk-flow model for determination of the leakage and dynamic force characteristics of angled injection Lomakin bearings is presented. Zeroth- and first-order equations describe the equilibrium flow for a centered bearing and the perturbed flow...
The Matrix of Unitarity Triangle Angles for Quarks
P. F. Harrison; S. Dallison; W. G. Scott
2009-10-18
In the context of quark (as for lepton) mixing, we introduce the concept of the matrix of unitarity triangle angles $\\Phi$, emphasising that it carries equivalent information to the complex mixing matrix $V$ itself. The angle matrix $\\Phi$ has the added advantage, with respect to $V$, of being both basis-and phase-convention independent and consequently observable (indeed several $\\Phi$-matrix entries, eg. $\\Phi_{cs}=\\alpha$, $\\Phi_{us}=\\beta$ etc. are already long-studied as directly measurable/measured in $B$-physics experiments). We give complete translation formulae between the mixing-matrix and angle-matrix representations. We go on to consider briefly the present state of the experimental data on the full angle matrix and some of the prospects for the future, with reference to both the quark and lepton cases.
Contact angle hysteresis: a review of fundamentals and applications
’t Mannetje, D. J. C. M.
Contact angle hysteresis is an important physical phenomenon. It is omnipresent in nature and also plays a crucial role in various industrial processes. Despite its relevance, there is a lack of consensus on how to incorporate ...
Tatara, Gen; Nakabayashi, Noriyuki
2014-05-07
Emergent electromagnetic field which couples to electron's spin in ferromagnetic metals is theoretically studied. Rashba spin-orbit interaction induces spin electromagnetic field which is in the linear order in gradient of magnetization texture. The Rashba-induced effective electric and magnetic fields satisfy in the absence of spin relaxation the Maxwell's equations as in the charge-based electromagnetism. When spin relaxation is taken into account besides spin dynamics, a monopole current emerges generating spin motive force via the Faraday's induction law. The monopole is expected to play an important role in spin-charge conversion and in the integration of spintronics into electronics.
Spin transport in lateral spin valves and across a metal- insulator transition in V?O? /
Erekhinsky, Mikhail
2013-01-01
J. Ansermet, Spin-dependent Peltier effect of perpendicularB. van Wees, Interplay of Peltier and Seebeck Effects inspin Seebeck coefficient. Peltier or spin blockade effects
Contact angle of sessile drops in Lennard-Jones systems
Stefan Becker; Herbert M. Urbassek; Martin Horsch; Hans Hasse
2015-07-25
Molecular dynamics simulation is used for studying the contact angle of nanoscale sessile drops on a planar solid wall in a system interacting via the truncated and shifted Lennard-Jones potential. The entire range between total wetting and dewetting is investigated by varying the solid--fluid dispersive interaction energy. The temperature is varied between the triple point and the critical temperature. A correlation is obtained for the contact angle in dependence of the temperature and the dispersive interaction energy. Size effects are studied by varying the number of fluid particles at otherwise constant conditions, using up to 150 000 particles. For particle numbers below 10 000, a decrease of the contact angle is found. This is attributed to a dependence of the solid-liquid surface tension on the droplet size. A convergence to a constant contact angle is observed for larger system sizes. The influence of the wall model is studied by varying the density of the wall. The effective solid-fluid dispersive interaction energy at a contact angle of 90 degrees is found to be independent of temperature and to decrease linearly with the solid density. A correlation is developed which describes the contact angle as a function of the dispersive interaction, the temperature and the solid density. The density profile of the sessile drop and the surrounding vapor phase is described by a correlation combining a sigmoidal function and an oscillation term.
Accepted Manuscript Using Small Angle Solution Scattering Data in Xplor-NIH Structure Calcula-
Clore, G. Marius
and wide angle X-ray and small angle neutron scattering for biomolecular structure calculation using and wide angle X-ray scattering (SAXS/WAXS) and small angle neutron scattering (SANS) data, on the otherAccepted Manuscript Using Small Angle Solution Scattering Data in Xplor-NIH Structure Calcula
Antiferromagnetic Spins Do The Twist
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications TraditionalWithAntiferromagnetic Spins Do The Twist Antiferromagnetic Spins
A New Spin on Photoemission Spectroscopy
Jozwiak, Chris
2010-01-01
18. Wolf, S. A. et al. Spintronics: A Spin-Based Electronicsthe electron spin (spintronics 17,18 ) explicitly relies onand crossed. Applied to spintronics materials and de- vices,
Vladimir Baryshevsky
2002-02-14
Spin rotation and oscillation phenomena of particles captured in a gas target through which beam of high energy particles passes is discussed. Such experiment arrangement make it realizable for storage ring and allows to study zero-angle scattering amplitude at highest possible energies.
How ARCO drills high-angle wells offshore Indonesia
Tjondrodiputro, B.; Eddyarso, H.; Jones, K. (Atlantic Richfield Indonesia, Inc., Jakarta (Indonesia))
1993-03-01
Atlantic Richfield Indonesia, Inc. (ARII) drilled and completed 28 high-angle wells since early 1986 in Bima, Papa and FF fields in the Offshore North West Java Sea (ONWJ) contract area. Early wells were drilled with conventional rotary bottomhole assemblies (BHAs); introduction of a steerable tool and MWD subsequently increased efficiency and reduced drilling costs. Both lignosulfonate and dispersed pac polymer muds have been used with good success. Cost to drill a high-angle well has been only marginally more than that of a 45[degree] directional well. Elimination of open hole logging and use of preperforated liners have reduced drilling costs by 10%. Production performance for wells has been higher than for vertical or low-angle wells. High-angle wells in Bima have outperformed offset vertical wells and are classified as a success. However, horizontal wells in Papa, which has a strong bottom-water drive, have not shown any improved recovery over conventional wells. The new well in FF field is still being evaluated. In this first of a two-part report, high-angle drilling operations including well planning, BHA selection, casing and mud programs, hole cleaning and logging are described. Specific wells in the Bima area are discussed as examples.
Spin-to-Orbital Angular Momentum Conversion and Spin-Polarization Filtering in Electron Beams
Marrucci, Lorenzo
Spin-to-Orbital Angular Momentum Conversion and Spin-Polarization Filtering in Electron Beams-variant Wien filter for electron beams that induces a spin half-turn and converts the corresponding spin-polarized electron beam, such a device can generate an electron vortex beam, carrying orbital angular momentum. When
Detection of atomic spin labels in a lipid bilayer using a single-spin nanodiamond probe
Scholten, Robert
Detection of atomic spin labels in a lipid bilayer using a single-spin nanodiamond probe Stefan conditions using a single-spin nanodiamond sensor. Changes in the spin relaxation time of the sensor located in a nanodiamondwhich is situated in the target structure itself and acts as a nanoscopic magnetic field detector
Inverse spin Hall effect induced by spin pumping into semiconducting ZnO
Lee, Jung-Chuan [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Huang, Leng-Wei [Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan (China); Hung, Dung-Shing, E-mail: dshung@mail.mcu.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Department of Information and Telecommunications Engineering, Ming Chuan University, Taipei 111, Taiwan (China); Chiang, Tung-Han [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Huang, J. C. A., E-mail: jcahuang@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Liang, Jun-Zhi [Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Physics, Fu Jen Catholic University, Taipei 242, Taiwan (China); Lee, Shang-Fan, E-mail: leesf@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan (China)
2014-02-03
The inverse spin Hall effect (ISHE) of n-type semiconductor ZnO thin films with weak spin-orbit coupling has been observed by utilizing the spin pumping method. In the ferromagnetic resonance condition, the spin pumping driven by the dynamical exchange interaction of a permalloy film injects a pure spin current into the adjacent ZnO layer. This spin current gives rise to a DC voltage through the ISHE in the ZnO layer, and the DC voltage is proportional to the microwave excitation power. The effect is sizeable even when the spin backflow is considered.
Quantum Spin Hall Eect May 9, 2011
Hall Eect Quantum Spin Hall Eect in Graphene QSHE in quantum well QSHE in strained semiconductor Tim Quantum Spin Hall Eect in Graphene QSHE in quantum well QSHE in strained semiconductor Tim Hsieh Quantum Hsieh Quantum Spin Hall Eect #12;Integer Quantum Hall Eect (IQHE) 2D electron gas at low temperature
Vivapure Metal Chelate Maxi spin columns
Lebendiker, Mario
® Vivapure Metal Chelate Maxi spin columns Hisn Technical data and operating instructions. For in vitro use only. #12;2 Handling overview Vivapure Metal Chelate Maxi spin columns - for the purification of proteins with poly-histidine tags Storage conditions Vivapure Metal Chelate Maxi spin columns can be stored
Vivapure Metal Chelate Mini spin columns
Lebendiker, Mario
® Vivapure Metal Chelate Mini spin columns Hisn Technical data and operating instructions. For in vitro use only. #12;2 Handling overview Vivapure Metal Chelate Mini spin columns - for the purification of proteins with poly-histidine tags Storage conditions Vivapure Metal Chelate Mini spin columns can be stored
Vivapure Metal Chelate Mega spin columns
Lebendiker, Mario
®® Vivapure Metal Chelate Mega spin columns Hisn Technical data and operating instructions. For in vitro use only. #12;2 Handling overview Vivapure Metal Chelate Mega spin columns - for the purification of proteins with poly-histidine tags Storage conditions Vivapure Metal Chelate Mega spin columns can be stored
Vivapure Metal Chelate Mini spin columns
Lebendiker, Mario
® Vivapure Metal Chelate Mini spin columns Hisn #12;E. coli cell lysates containing a recombinant Hisn-tagged protein were purified using Vivapure Metal Chelate Mini spin columns and competitor products. The Vivapure Metal Chelate Mini spin columns were pre- loaded with different metal ions
High-spin nuclear spectroscopy
Diamond, R.M.
1986-07-01
High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given. (DWL)
Switzner, Nathan; Henry, Dick
2009-03-20
In a second development order, spin-forming equipment was again evaluated using the test shape, a hemispherical shell. In this second development order, pure vanadium and alloy titanium (Ti-6Al-4V) were spin-formed, as well as additional copper and 21-6-9 stainless. In the first development order the following materials had been spin-formed: copper (alloy C11000 ETP), 6061 aluminum, 304L stainless steel, 21-6-9 stainless steel, and tantalum-2.5% tungsten. Significant challenges included properly adjusting the rotations-per-minute (RPM), cracking at un-beveled edges and laser marks, redressing of notches, surface cracking, non-uniform temperature evolution in the titanium, and cracking of the tailstock. Lessons learned were that 300 RPM worked better than 600 RPM for most materials (at the feed rate of 800 mm/min); beveling the edges to lower the stress reduces edge cracking; notches, laser marks, or edge defects in the preform doom the process to cracking and failure; coolant is required for vanadium spin-forming; increasing the number of passes to nine or more eliminates surface cracking for vanadium; titanium develops a hot zone in front of the rollers; and the tailstock should be redesigned to eliminate the cylindrical stress concentrator in the center.
SPINNING THE SEMANTIC WEB INTRODUCTION
Wahlster, Wolfgang - Deutsche Forschungszentrum für Künstliche Intelligenz & FR 6.2
SPINNING THE SEMANTIC WEB INTRODUCTION Dieter Fensel, Jim Hendler, Henry Lieberman, and Wolfgang Wahlster The World Wide Web (WWW) has drastically changed the availability of electronically accessible (http://www.w3c.org) expects around a billion Web users and an even higher number of available documents
S. J. Balian; M. B. A. Kunze; M. H. Mohammady; G. W. Morley; W. M. Witzel; C. W. M. Kay; T. S. Monteiro
2012-10-08
We present pulsed electron-nuclear double resonance (ENDOR) experiments which enable us to characterize the coupling between bismuth donor spin qubits in Si and the surrounding spin bath of 29Si impurities which provides the dominant decoherence mechanism (nuclear spin diffusion) at low temperatures (expansion simulations show near-complete suppression of spin diffusion, at optimal working points. The suppression takes the form of sharply peaked divergences of the spin diffusion coherence time, in contrast with previously identified broader regions of insensitivity to classical fluctuations. ENDOR data suggest that anisotropic contributions are comparatively weak, so the form of the divergences is largely independent of crystal orientation.
Zhou, Benhu Zeng, Yangsu; Zhou, Benliang; Zhou, Guanghui; Ouyang, Tao
2015-03-14
We theoretically investigate spin-dependent Seebeck effects for a system consisting of a narrow graphene nanoribbon (GNR) contacted to square lattice ferromagnetic (FM) electrodes with noncollinear magnetic moments. Both zigzag-edge graphene nanoribbons (ZGNRs) and armchair-edge graphene nanoribbons (AGNRs) were considered. Compared with our previous work with two-dimensional honeycomb-lattice FM leads, a more realistic model of two-dimensional square-lattice FM electrodes is adopted here. Using the nonequilibrium Green's function method combining with the tight-binding Hamiltonian, it is demonstrated that both the charge Seebeck coefficient S{sub C} and the spin-dependent Seebeck coefficient S{sub S} strongly depend on the geometrical contact between the GNR and the leads. In our previous work, S{sub C} for a semiconducting 15-AGNR system near the Dirac point is two orders of magnitude larger than that of a metallic 17-AGNR system. However, S{sub C} is the same order of magnitude for both metallic 17-AGNR and semiconducting 15-AGNR systems in the present paper because of the lack of a transmission energy gap for the 15-AGNR system. Furthermore, the spin-dependent Seebeck coefficient S{sub S} for the systems with 20-ZGNR, 17-AGNR, and 15-AGNR is of the same order of magnitude and its maximum absolute value can reach 8??V/K. The spin-dependent Seebeck effects are not very pronounced because the transmission coefficient weakly depends on spin orientation. Moreover, the spin-dependent Seebeck coefficient is further suppressed with increasing angle between the relative alignments of magnetization directions of the two leads. Additionally, the spin-dependent Seebeck coefficient can be strongly suppressed for larger disorder strength. The results obtained here may provide valuable theoretical guidance in the experimental design of heat spintronic devices.
Spinning Reserve From Responsive Loads
Kirby, B.J.
2003-04-08
Responsive load is the most underutilized reliability resource available to the power system today. It is currently not used at all to provide spinning reserve. Historically there were good reasons for this, but recent technological advances in communications and controls have provided new capabilities and eliminated many of the old obstacles. North American Electric Reliability Council (NERC), Federal Energy Regulatory Commission (FERC), Northeast Power Coordinating Council (NPCC), New York State Reliability Council (NYSRC), and New York Independent System Operator (NYISO) rules are beginning to recognize these changes and are starting to encourage responsive load provision of reliability services. The Carrier ComfortChoice responsive thermostats provide an example of these technological advances. This is a technology aimed at reducing summer peak demand through central control of residential and small commercial air-conditioning loads. It is being utilized by Long Island Power Authority (LIPA), Consolidated Edison (ConEd), Southern California Edison (SCE), and San Diego Gas and Electric (SDG&E). The technology is capable of delivering even greater response in the faster spinning reserve time frame (while still providing peak reduction). Analysis of demand reduction testing results from LIPA during the summer of 2002 provides evidence to back up this claim. It also demonstrates that loads are different from generators and that the conventional wisdom, which advocates for starting with large loads as better ancillary service providers, is flawed. The tempting approach of incrementally adapting ancillary service requirements, which were established when generators were the only available resources, will not work. While it is easier for most generators to provide replacement power and non-spinning reserve (the slower response services) than it is to supply spinning reserve (the fastest service), the opposite is true for many loads. Also, there is more financial reward for supplying spinning reserve than for supplying the other reserve services as a result of the higher spinning reserve prices. The LIPAedge program (LIPA's demand reduction program using Carrier ComfortChoice thermostats) provides an opportunity to test the use of responsive load for spinning reserve. With potentially 75 MW of spinning reserve capability already installed, this test program can also make an important contribution to the capacity needs of Long Island during the summer of 2003. Testing could also be done at ConEd ({approx}30 MW), SCE ({approx}15 MW), and/or SDG&E ({approx}15 MW). This paper is divided into six chapters. Chapter 2 discusses the contingency reserve ancillary services, their functions in supporting power system reliability, and their technical requirements. It also discusses the policy and tariff requirements and attempts to distinguish between ones that are genuinely necessary and ones that are artifacts of the technologies that were historically used to provide the services. Chapter 3 discusses how responsive load could provide contingency reserves (especially spinning reserve) for the power system. Chapter 4 specifically discusses the Carrier ComfortChoice responsive thermostat technology, the LIPAedge experience with that technology, and how the technology could be used to supply spinning reserve. Chapter 5 discusses a number of unresolved issues and suggests areas for further research. Chapter 6 offers conclusions and recommendations.
Extremal Higher Spin Black Holes
Máximo Bañados; Alejandra Castro; Alberto Faraggi; Juan I. Jottar
2015-11-30
The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require nor implies the existence of supersymmetry, we exemplify its consequences in the context of sl(3|2) + sl(3|2) Chern-Simons theory. Remarkably, while as usual not all extremal solutions preserve supersymmetries, we find that the higher spin setup allows for non-extremal supersymmetric black hole solutions as well. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) + sl(3|2) Chern-Simons theory and two-dimensional CFTs with W_{(3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W_{(3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.
Winding angle distributions for two-dimensional collapsing polymers
Arturo Narros; Aleksander L Owczarek; Thomas Prellberg
2015-10-28
We provide numerical support for a long-standing prediction of universal scaling of winding angle distributions. Simulations of interacting self-avoiding walks show that the winding angle distribution for $N$-step walks is compatible with the theoretical prediction of a Gaussian with a variance growing asymptotically as $C\\log N$, with $C=2$ in the swollen phase (previously verified), and $C=24/7$ at the $\\theta$-point. At low temperatures weaker evidence demonstrates compatibility with the same scaling and a value of $C=4$ in the collapsed phase, also as theoretically predicted.
Winding angle distributions for two-dimensional collapsing polymers
Arturo Narros; Aleksander L Owczarek; Thomas Prellberg
2015-11-03
We provide numerical support for a long-standing prediction of universal scaling of winding angle distributions. Simulations of interacting self-avoiding walks show that the winding angle distribution for $N$-step walks is compatible with the theoretical prediction of a Gaussian with a variance growing asymptotically as $C\\log N$, with $C=2$ in the swollen phase (previously verified), and $C=24/7$ at the $\\theta$-point. At low temperatures weaker evidence demonstrates compatibility with the same scaling and a value of $C=4$ in the collapsed phase, also as theoretically predicted.
Cerchiai, Bianca L; Bertini, S.; Cacciatori, Sergio L.
2005-10-20
In this paper we reconsider the problem of the Euler parametrization for the unitary groups. After constructing the generic group element in terms of generalized angles, we compute the invariant measure on SU(N) and then we determine the full range of the parameters, using both topological and geometrical methods. In particular, we show that the given parametrization realizes the group SU(N+1) as a fibration of U(N) over the complex projective space CP{sup n}. This justifies the interpretation of the parameters as generalized Euler angles.
Ohta, Shigemi
NSAC Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 RHIC SPIN: Experimental Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 Spin Physics at RHIC o Spin Structure Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 Parton Distribution functions (PDF
Colin, Pierre; Acosta, Monica Vazquez; Pfrommer, Christoph; Pinzke, Anders
2015-01-01
Galaxy clusters are the largest and most massive gravitationally bound structures known in the Universe. Cosmic-Ray (CR) hadrons accelerated at structure formation shocks and injected by galaxies, are confined in galaxy clusters where they accumulate for cosmological times. The presence of diffuse synchrotron radio emission in several clusters proves the existence of high-energy electrons, and magnetic fields. However, a direct proof of CR proton acceleration is missing. The presence of CR protons can be probe through the diffuse gamma-ray emission induced by their hadronic interaction with the Intra-Cluster Medium (ICM). The Perseus cluster, a nearby cool-core cluster, has been identified to be among the best candidates to detect such emission. We present here the results of a very deep observation of the Perseus cluster with the MAGIC telescopes, accumulating about 250 hours of data from 2009 to 2014. No evidence of large-scale very-high-energy gamma-ray emission from CR-ICM interactions has been detected. ...
Noeel, N. E. D.; Read, J. I. [ETH Zuerich, Institute for Astronomy, Wolfgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland); Conn, B. C.; Rix, H.-W. [Max Planck Institut fuer Astronomie, Koenigstuhl 17, D-69117, Heidelberg (Germany); Carrera, R. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38200, La Laguna, Tenerife (Spain); Dolphin, A., E-mail: noelia@phys.ethz.ch [Raytheon Company, P.O. Box 11337, Tucson, AZ 85734-1337 (United States)
2013-05-10
The origin of the gas in between the Magellanic Clouds (MCs)-known as the ''Magellanic Bridge'' (MB)-is puzzling. Numerical simulations suggest that the MB formed from tidally stripped gas and stars in a recent interaction between the MCs. However, the apparent lack of stripped intermediate- or old-age stars associated with the MB is at odds with this picture. In this paper, we present the first results from the MAGellanic Inter-Cloud program (MAGIC) aimed at probing the stellar populations in the inter-Cloud region. We present observations of the stellar populations in two large fields located in between the Large and Small Magellanic Clouds (LMC/SMC), secured using the WFI camera on the 2.2 m telescope in La Silla. Using a synthetic color-magnitude diagram technique, we present the first quantitative evidence for the presence of intermediate-age and old stars in the inter-Cloud region. The intermediate-age stars-which make up {approx}28% of all stars in the region-are not present in fields at a similar distance from the SMC in a direction pointing away from the LMC. This provides potential evidence that these intermediate-age stars could have been tidally stripped from the SMC. However, spectroscopic studies will be needed to confirm or rule out the tidal origin for the inter-Cloud gas and stars.
2002-01-01
by using small angle neutron scattering Winnie Yong †‡ ,technique of small angle neutron scattering has been used tois small angle neutron scattering (SANS). SANS experiments
Rapid and robust spin state amplification
Tom Close; Femi Fadugba; Simon C. Benjamin; Joseph Fitzsimons; Brendon W. Lovett
2011-05-24
Electron and nuclear spins have been employed in many of the early demonstrations of quantum technology (QT). However applications in real world QT are limited by the difficulty of measuring single spins. Here we show that it is possible to rapidly and robustly amplify a spin state using a lattice of ancillary spins. The model we employ corresponds to an extremely simple experimental system: a homogenous Ising-coupled spin lattice in one, two or three dimensions, driven by a continuous microwave field. We establish that the process can operate at finite temperature (imperfect initial polarisation) and under the effects of various forms of decoherence.
Universality in higher order spin noise spectroscopy
Li, Fuxiang
2015-01-01
Higher order time-correlators of spontaneous spin fluctuations reveal the information about spin interactions. We argue that in a broad class of spin systems one can justify a phenomenological approach to explore such correlators. Thus, we predict that the 3rd and 4th order spin cumulants are described by a universal function that can be parametrized by a small set of parameters. We show that the fluctuation theorem constrains this function so that such correlators are fully determined by lowest nonlinear corrections to the free energy and the mean and variance of microscopic spin currents. We also provide an example of microscopic calculations for conduction electrons.
Spin-Spin Coupling in the Solar System
Batygin, Konstantin
2015-01-01
The richness of dynamical behavior exhibited by the rotational states of various solar system objects has driven significant advances in the theoretical understanding of their evolutionary histories. An important factor that determines whether a given object is prone to exhibiting non-trivial rotational evolution is the extent to which such an object can maintain a permanent aspheroidal shape, meaning that exotic behavior is far more common among the small body populations of the solar system. Gravitationally bound binary objects constitute a substantial fraction of asteroidal and TNO populations, comprising systems of triaxial satellites that orbit permanently deformed central bodies. In this work, we explore the rotational evolution of such systems with specific emphasis on quadrupole-quadrupole interactions, and show that for closely orbiting, highly deformed objects, both prograde and retrograde spin-spin resonances naturally arise. Subsequently, we derive capture probabilities for leading order commensur...
Geometric spin manipulation in semiconductor quantum dots
Prabhakar, Sanjay Melnik, Roderick; Inomata, Akira
2014-04-07
We propose a method to flip the spin completely by an adiabatic transport of quantum dots. We show that it is possible to flip the spin by inducing a geometric phase on the spin state of a quantum dot. We estimate the geometric spin flip time (approximately 2 ps) which turned out to be much shorter than the experimentally reported decoherence time (approximately 100 ns) that would provide an alternative means of fliping the spin before reaching decoherence. It is important that both the Rashba coupling and the Dresselhaus coupling are present for inducing a phase necessary for spin flip. If one of them is absent, the induced phase is trivial and irrelevant for spin-flip.
Rueda, D.R.; Garcia-Gutierrez, M.C.; Nogales, A.; Capitan, M.J.; Ezquerra, T.A.; Labrador, A.; Fraga, E.; Beltran, D.; Juanhuix, J.; Herranz, J.F.; Bordas, J. [Instituto de Estructura de la Materia, CSIC, Serrano 119, 28006 Madrid (Spain); LLS, BM16-ESRF, 6 rue Jules Horowitz, BP220, 38043 Grenoble (France)
2006-03-15
Here we present a novel, simple, and versatile experimental setup aimed to perform wide angle x-ray scattering (WAXS) measurements alone or in simultaneous combination with small angle x-ray scattering measurements. The design of the WAXS goniometer allows one to obtain high resolution diffraction patterns in a broad angular range. The setup can incorporate a hot stage in order to evaluate temperature resolved experiments. The performance of the equipment has been verified in the BM16 beam line of the European Synchrotron Radiation Facility with different well known samples such as alumina, isotropic film of high density polyethylene (HDPE), and oriented HPDE fiber.
Wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence
Bitter, M.; Hill, K. W.; Scott, S.; Feder, R.; Ko, Jinseok; Ince-Cushman, A.; Rice, J. E.
2008-10-15
The paper describes a new scheme for wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence by a matched pair of spherically bent crystals to eliminate the astigmatism, which is a well-known imaging error of spherical mirrors. In addition to x rays, the scheme should be applicable to a very broad spectrum of the electromagnetic radiation, including microwaves, infrared and visible light, as well as UV and extreme UV radiation, if the crystals are replaced with appropriate spherical reflectors. The scheme may also be applicable to the imaging with ultrasound.
Experimental Evaluation of an Angle Based Indoor Localization System
Nasipuri, Asis
Experimental Evaluation of an Angle Based Indoor Localization System Asis Nasipuri and Ribal El available off-the-shelf components. Wireless sensor nodes equipped with photo sensors determine is required at the sensor nodes. The system also does not involve any centralized server or off
Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation
Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation Clemens Jauch Risø National Laboratory Wind Energy Department P.O. Box 49 DK-4000 Roskilde, Denmark clemens.jauch@risoe.dk Abstract: In this paper it is investigated how active-stall wind turbines can contribute to the stabilisation of the power
Brook Trout Angling in Maine 2009 Survey Results
Thomas, Andrew
Brook Trout Angling in Maine 2009 Survey Results Marc Edwards University of Maine Cooperative Extension Franklin County Office A Cooperative Project between the University of Maine Cooperative Extension and Maine Department of Inland Fisheries and Wildlife #12;2 Background In a meeting at University of Maine
Application of High-Angle Annular Dark Field Scanning Transmission
Utsunomiya, Satoshi
Application of High-Angle Annular Dark Field Scanning Transmission Electron Microscopy, Scanning Transmission Electron Microscopy-Energy Dispersive X-ray Spectrometry, and Energy-Filtered Transmission at the nanoscale. Atomic-scale techniques, such as conventional transmission electron microscopy, although powerful
PRTAD: A DATABASE FOR PROTEIN RESIDUE TORSION ANGLE DISTRIBUTIONS
PRTAD: A DATABASE FOR PROTEIN RESIDUE TORSION ANGLE DISTRIBUTIONS By Xiaoyong Sun Di Wu RobertÂ0436 Phone: 612-624-6066 Fax: 612-626-7370 URL: http://www.ima.umn.edu #12;PRTAD: A Database for Protein@iastate.edu Abstract PRTAD is a dedicated database and structural bioinformatics system for protein analysis
Real-Time Security Assessment of Angle Stability Using Synchrophasors
-time operations, be it angle stability or voltage stability. PMU deployment is becoming a common practice across of ap- plications to make use of PMU data has not been at the same pace. This project also analyzes how PMU data can be used to
SANS -Small Angle Neutron Scattering Tcnica de difrao
Loh, Watson
SANS - Small Angle Neutron Scattering Técnica de difração informações sobre tamanho e forma de- Neutrons are created in the centre of the target station when the beam of high energy protons collides by evaporating nuclear particles, mainly neutrons, in all directions. Each proton produces approximately 15
Azimuthal angle dependence of di-jet production in unpolarized hadron scattering
Lu Zhun; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Valparaiso (Chile) and Center of Subatomic Physics, Valparaiso (Chile)
2009-08-04
We study the azimuthal asymmetry of back-to-back di-jet production in unpolarized hadron scattering, arising from the product of two Boer-Mulders functions, which describe the transverse spin distribution of quarks inside an unpolarized hadron. We find that there is a cos {delta}{phi} angular dependence of the di-jet, with {delta}{phi} the difference of the azimuthal angle of tow jets respectively. In the case of J{sub q}+J{sub q} production, we find that there is a color factor enhancement in the gluonic cross-section due to the multiple initial-/final-state interactions, compared with the result from the standard generalized parton model. We estimate the cos {delta}{phi} asymmetry of the total di-jet production at RHIC, showing that the color factor enhancement in the azimuthal asymmetric cross section of J{sub q}+J{sub q} production will reverse the sign of the asymmetry.
Realization of tunable spin-dependent splitting in intrinsic photonic spin Hall effect
Ling, Xiaohui [SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Laboratory for spin photonics, College of Physics and Microelectronic Science, Hunan University, Changsha 410082 (China); Department of Physics and Electronic Information Science, Hengyang Normal University, Hengyang 421002 (China); Yi, Xunong [SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Zhou, Xinxing; Liu, Yachao; Shu, Weixing; Wen, Shuangchun [Laboratory for spin photonics, College of Physics and Microelectronic Science, Hunan University, Changsha 410082 (China); Luo, Hailu, E-mail: hailuluo@hnu.edu.cn [SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Laboratory for spin photonics, College of Physics and Microelectronic Science, Hunan University, Changsha 410082 (China)
2014-10-13
We report the realization of tunable spin-dependent splitting in intrinsic photonic spin Hall effect. By breaking the rotational symmetry of a cylindrical vector beam, the intrinsic vortex phases that the two spin components of the vector beam carries, which is similar to the geometric Pancharatnam-Berry phase, are no longer continuous in the azimuthal direction, and leads to observation of spin accumulation at the opposite edge of the beam. Due to the inherent nature of the phase and independency of light-matter interaction, the observed photonic spin Hall effect is intrinsic. Modulating the topological charge of the vector beam, the spin-dependent splitting can be enhanced and the direction of spin accumulation is switchable. Our findings may provide a possible route for generation and manipulation of spin-polarized photons, and enables spin-based photonics applications.
Pumice-pumice collisions and the effect of the impact angle B. Cagnoli and M. Manga
Manga, Michael
results show that the rebound angle, the ratios of the components of velocities and the energy loss vary observed relatively larger rebound angles at small and large impact angles and smaller values in between the impact angle increases. Furthermore, the ratio of the kinetic energy after to that before collisions
Lichtenegger, Helga C.
Variation of Cellulose Microfibril Angles in Softwoods and Hardwoods-- A Possible Strategy beech). The tilt angle of the cellulose fibrils in the wood cell wall versus the longitudinal cell axis Words: cellulose; hardwood; microfibril angle; small-angle scattering; softwood; wood; X
Small-Angle Neutron Scattering Studies of Charged Carboxyl-Terminated Dendrimers in Solutions
Dubin, Paul D.
Small-Angle Neutron Scattering Studies of Charged Carboxyl-Terminated Dendrimers in Solutions Q. R-angle neutron scattering was used to characterize the solution behavior of charged carboxylic acid terminated- copy,16 small-angle X-ray scattering,17 and small-angle neutron scattering (SANS),18-25 have been used
Demand Response Spinning Reserve Demonstration
Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.
2007-05-01
The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.
Ab initio non-relativistic spin dynamics
Ding, Feizhi; Goings, Joshua J.; Li, Xiaosong; Frisch, Michael J.
2014-12-07
Many magnetic materials do not conform to the (anti-)ferromagnetic paradigm where all electronic spins are aligned to a global magnetization axis. Unfortunately, most electronic structure methods cannot describe such materials with noncollinear electron spin on account of formally requiring spin alignment. To overcome this limitation, it is necessary to generalize electronic structure methods and allow each electron spin to rotate freely. Here, we report the development of an ab initio time-dependent non-relativistic two-component spinor (TDN2C), which is a generalization of the time-dependent Hartree-Fock equations. Propagating the TDN2C equations in the time domain allows for the first-principles description of spin dynamics. A numerical tool based on the Hirshfeld partitioning scheme is developed to analyze the time-dependent spin magnetization. In this work, we also introduce the coupling between electron spin and a homogenous magnetic field into the TDN2C framework to simulate the response of the electronic spin degrees of freedom to an external magnetic field. This is illustrated for several model systems, including the spin-frustrated Li{sub 3} molecule. Exact agreement is found between numerical and analytic results for Larmor precession of hydrogen and lithium atoms. The TDN2C method paves the way for the ab initio description of molecular spin transport and spintronics in the time domain.
Observation of strongly enhanced inverse spin Hall voltage in Fe{sub 3}Si/GaAs structures
Hung, H. Y.; Kwo, J., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw, E-mail: leesf@phys.sinica.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Chiang, T. H. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Syu, B. Z.; Fanchiang, Y. T.; Hong, M., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw, E-mail: leesf@phys.sinica.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Lin, J. G. [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Lee, S. F., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw, E-mail: leesf@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China)
2014-10-13
We performed spin pumping experiment on high quality, epitaxial Fe{sub 3}Si/GaAs structures grown by molecular beam epitaxy. By tailoring the thickness and doping (n, p) level of the conducting GaAs epi-layer, thermal heating common of ferromagnetic metal/semiconductor heterostructure was removed effectively. A large inverse spin Hall Effect (ISHE) voltage up to 49.2??V was observed for Fe{sub 3}Si/p-GaAs. Smaller ISHE voltage (V{sub ISHE}) by a factor of ?0.4 was obtained for Fe{sub 3}Si/n-GaAs, as scaled with its resistivity. By taking into account of the “self-induced” ISHE apparently observed in our samples, the minimum value of spin Hall angle ?{sub ISHE} for n-GaAs and p-GaAs was estimated to be 1.9 × 10{sup ?4} and 2.8 × 10{sup ?5}, respectively.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; et al
2012-05-24
A measurement of spin correlation in tt¯ production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb?¹. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to Ahelicity=0.40+0.09-0.08, in agreement with the next-to-leading-order standard model prediction. The hypothesis of zero spin correlation ismore »excluded at 5.1 standard deviations.« less
Spin-dependent transport in a nanopillar non-local spin valve J.-B. Laloe a,, T. Yang a
Otani, Yoshichika
Spin-dependent transport in a nanopillar non-local spin valve J.-B. Lalo¨e a,Ã, T. Yang a , T: Lateral spin-valve Spin current a b s t r a c t We investigate the injection of a pure spin current into a non-magnetic Cu wire in a lateral spin valve. We detect the spin accumulation occurring
Two-Step Nucleation and Growth of InP Quantum Dots via Magic-Sized Cluster Intermediates
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gary, Dylan C.; Terban, Maxwell W.; Billinge, Simon J. L.; Cossairt, Brandi M.
2015-01-30
We report on the role of magic-sized clusters (MSCs) as key intermediates in the synthesis of indium phosphide quantum dots (InP QDs) from molecular precursors. These observations suggest that previous efforts to control nucleation and growth by tuning precursor reactivity have been undermined by formation of these kinetically persistent MSCs prior to QD formation. The thermal stability of InP MSCs is influenced by the presence of exogenous bases as well as choice of the anionic ligand set. Addition of a primary amine, a common additive in previous InP QD syntheses, to carboxylate terminated MSCs was found to bypass the formationmore »of MSCs, allowing for homogeneous growth of InP QDs through a continuum of isolable sizes. Substitution of the carboxylate ligand set for a phosphonate ligand set increased the thermal stability of one particular InP MSC to 400°C. The structure and optical properties of the MSCs with both carboxylate and phosphonate ligand sets were studied by UV-Vis absorption spectroscopy, powder XRD analysis, and solution ³¹P{¹H} and ¹H NMR spectroscopy. Finally, the carboxylate terminated MSCs were identified as effective single source precursors (SSPs) for the synthesis of high quality InP QDs. Employing InP MSCs as SSPs for QDs effectively decouples the formation of MSCs from the subsequent second nucleation event and growth of InP QDs. The concentration dependence of this SSP reaction, as well as the shape uniformity of particles observed by TEM suggests that the stepwise growth from MSCs directly to QDs proceeds via a second nucleation event rather than an aggregative growth mechanism.« less
Tidal deformations of a spinning compact object
Pani, Paolo; Maselli, Andrea; Ferrari, Valeria
2015-01-01
The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole mom...
Cavity cooling of an ensemble spin system
Christopher J. Wood; Troy W. Borneman; David G. Cory
2014-02-24
We describe how sideband cooling techniques may be applied to large spin ensembles in magnetic resonance. Using the Tavis-Cummings model in the presence of a Rabi drive, we solve a Markovian master equation describing the joint spin-cavity dynamics to derive cooling rates as a function of ensemble size. Our calculations indicate that the coupled angular momentum subspaces of a spin ensemble containing roughly $10^{11}$ electron spins may be polarized in a time many orders of magnitude shorter than the typical thermal relaxation time. The described techniques should permit efficient removal of entropy for spin-based quantum information processors and fast polarization of spin samples. The proposed application of a standard technique in quantum optics to magnetic resonance also serves to reinforce the connection between the two fields, which has recently begun to be explored in further detail due to the development of hybrid designs for manufacturing noise-resilient quantum devices.
Nuclear spin noise in NMR revisited
Ferrand, Guillaume; Luong, Michel; Desvaux, Hervé
2015-01-01
The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite, preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR resonance linewidth as a function of the transmission line phase, nuclear spin-noise signals appearing as a "bump" or as a "dip" superimposed on the average electronic noise level even for a spin system and probe at the same temperature, pure in-phase Lorentzian spin-noise signals exhibiting non-vanishing frequency shifts. Extensive comparison to experimental measurements validate the model predictions, and define the conditions for obtaining pure in-phase Lorentzian-shape nuclear spin noise with a vanishing frequency shift, in other words, the conditions for simultaneously obtaining the Spin-Noise and Frequency-Shift Tuning Optima.
Upper bound on parity-violating neutron spin rotation in {sup 4}He
Snow, W. M.; Luo, D.; Walbridge, S. B.; Crawford, B. E.; Gan, K.; Micherdzinska, A. M.; Opper, A. K.; Heckel, B. R.; Swanson, H. E.; Sharapov, E. I.; Zhumabekova, V.
2011-02-15
We report an upper bound on parity-violating neutron spin rotation in {sup 4}He. This experiment is the most sensitive search for neutron-weak optical activity yet performed and represents a significant advance in precision in comparison to past measurements in heavy nuclei. The experiment was performed at the NG-6 slow-neutron beamline at the National Institute of Standards and Technology (NIST) Center for Neutron Research. Our result for the neutron spin rotation angle per unit length in {sup 4}He is d{phi}/dz=[+1.7{+-}9.1(stat.){+-}1.4(sys.)]x10{sup -7} rad/m. The statistical uncertainty is smaller than current estimates of the range of possible values of d{phi}/dz in n+{sup 4}He.
Small angle neutron scattering in materials science: Recent practical applications
Melnichenko, Yuri B [ORNL; Wignall, George D [ORNL
2007-01-01
Modern materials science and engineering relies increasingly on detailed knowledge of the structure and interactions in 'soft' and 'hard' materials, but there have been surprisingly few microscopic techniques for probing the structures of bulk samples of these substances. Small-angle neutron scattering (SANS) was first recognized in Europe as a major technique for this purpose and, over the past several decades, has been a growth area in both academic and industrial materials research to provide structural information on length scales {approx}10-1000 Angstroms (or 1-100 nm). The technique of ultrahigh resolution small-angle neutron scattering (USANS) raises the upper resolution limit for structural studies by more than two orders of magnitude and (up to {approx}30 {micro}m) and hence overlaps with light scattering and microscopy. This review illustrates the ongoing vitality of SANS and USANS in materials research via a range of current practical applications from both soft and hard matter nanostructured systems.
Guidance system for low angle silicon ribbon growth
Jewett, David N. (Harvard, MA); Bates, Herbert E. (Ashby, MA); Milstein, Joseph B. (Denver, CO)
1986-07-08
In a low angle silicon sheet growth process, a puller mechanism advances a seed crystal and solidified ribbon from a cooled growth zone in a melt at a low angle with respect to the horizontal. The ribbon is supported on a ramp adjacent the puller mechanism. Variations in the vertical position of the ribbon with respect to the ramp are isolated from the growth end of the ribbon by (1) growing the ribbon so that it is extremely thin, preferably less than 0.7 mm, (2) maintaining a large growth zone, preferably one whose length is at least 5.0 cm, and (3) spacing the ramp from the growth zone by at least 15 cm.
Metal oxide morphology in argon-assisted glancing angle deposition
Sorge, J. B.; Taschuk, M. T.; Wakefield, N. G.; Sit, J. C.; Brett, M. J. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4 (Canada); Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4 (Canada) and NRC National Institute for Nanotechnology, Edmonton, AB T6G 2M9 (Canada)
2012-03-15
Glancing angle deposition (GLAD) is a thin film deposition technique capable of fabricating columnar architectures such as posts, helices, and chevrons with control over nanoscale film features. Argon bombardment during deposition modifies the GLAD process, producing films with new morphologies which have shown promise for sensing and photonic devices. The authors report modification of column tilt angle, film density, and specific surface area for 12 different metal oxide and fluoride film materials deposited using Ar-assisted GLAD. For the vapor flux/ion beam geometry and materials studied here, with increasing argon flux, the column tilt increases, film density increases, and specific surface area decreases. With a better understanding of the nature of property modification and the mechanisms responsible, the Ar-assisted deposition process can be more effectively targeted towards specific applications, including birefringent thin films or photonic crystal square spirals.
Polar rotation angle identifies elliptic islands in unsteady dynamical systems
Mohammad Farazmand; George Haller
2015-03-20
We propose rotation inferred from the polar decomposition of the flow gradient as a diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical systems. We consider here two- and three-dimensional systems, in which polar rotation can be characterized by a single angle. For this polar rotation angle (PRA), we derive explicit formulas using the singular values and vectors of the flow gradient. We find that closed level sets of the PRA reveal elliptic islands in great detail, and singular level sets of the PRA uncover centers of such islands. Both features turn out to be objective (frame-invariant) for two-dimensional systems. We illustrate the diagnostic power of PRA for elliptic structures on several examples.
Polar rotation angle identifies elliptic islands in unsteady dynamical systems
Farazmand, Mohammad
2015-01-01
We propose rotation inferred from the polar decomposition of the flow gradient as a diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical systems. We consider here two- and three-dimensional systems, in which polar rotation can be characterized by a single angle. For this polar rotation angle (PRA), we derive explicit formulas using the singular values and vectors of the flow gradient. We find that closed level sets of the PRA reveal elliptic islands in great detail, and singular level sets of the PRA uncover centers of such islands. Both features turn out to be objective (frame-invariant) for two-dimensional systems. We illustrate the diagnostic power of PRA for elliptic structures on several examples.
Pitch-angle scattering of energetic particles with adiabatic focusing
Tautz, R. C. [Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstraße 36, D-10623 Berlin (Germany); Shalchi, A. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Dosch, A., E-mail: robert.c.tautz@gmail.com, E-mail: andreasm4@yahoo.com, E-mail: alexanderm.dosch@gmail.com [Center for Space Plasmas and Aeronomic Research, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States)
2014-10-20
Understanding turbulent transport of charged particles in magnetized plasmas often requires a model for the description of random variations in the particle's pitch angle. The Fokker-Planck coefficient of pitch-angle scattering, which is used to describe scattering parallel to the mean magnetic field, is therefore of central importance. Whereas quasi-linear theory assumes a homogeneous mean magnetic field, such a condition is often not fulfilled, especially for high-energy particles. Here, a new derivation of the quasi-linear approach is given that is based on the unperturbed orbit found for an adiabatically focused mean magnetic field. The results show that, depending on the ratio of the focusing length and the particle's Larmor radius, the Fokker-Planck coefficient is significantly modified but agrees with the classical expression in the limit of a homogeneous mean magnetic field.
The 2mrad Crossing Angle Interaction Region and Extraction Line
Appleby, R.; U., Manchester; Angal-Kalinin, D.; Dadoun, O.; Bambade, P.; Parker, B.; Keller, L.; Moffeit, K.; Nosochkov, Y.; Seryi, A.; Spencer, C.; Carter, J.; Royal Holloway, U.of London; Napoly, O.; /DAPNIA, Saclay
2006-07-12
A complete optics design for the 2mrad crossing angle interaction region and extraction line was presented at Snowmass 2005. Since this time, the design task force has been working on developing and improving the performance of the extraction line. The work has focused on optimizing the final doublet parameters and on reducing the power losses resulting from the disrupted beam transport. In this paper, the most recent status of the 2mrad layout and the corresponding performance are presented.
Studies of transverse spin effects at Jlab
Harutyun Avakian; Peter Bosted; Volker Burkert; Latifa Elouadrhiri
2006-06-01
We present ongoing and future studies of single-spin asymmetries in semi-inclusive electroproduction of pions using the CEBAF polarized electron beam. Kinematic dependences of single-spin asymmetries have been measured in a wide kinematic range at CLAS with a polarized NH{sub 3} target. Significant target-spin sin 2{phi} and sin {phi} asymmetries have been observed, indicating a non-zero Collins fragmentation function and supporting future SIDIS measurements with upgraded JLab.
Applications of Trajectory Solid Angle for Probabilistic Safety Assessment
Wong, Po Kee; Wong, Adam E.; Wong, Anita
2002-07-01
In 1974, a well-known research problem in Statistical Mechanics entitled 'To determine and define the probability function P.sub.2 of a particle hitting a predetermined area, given all its parameters of generation and ejection' was openly solicited for its solution from research and development organizations in U.S.A. One of many proposed solutions of the problem, initiated at that time, is by means of the Trajectory Solid Angle (TSA). TSA is defined as the integral of the dot product of the unit tangent of the particle's trajectory to the vector area divided by the square of the position vector connecting between the point of ejection and that of the surface to be hit. The invention provides: (1) The precise and the unique solution of a previously unsolved P.sub.2 problem: (2) Impacts to the governmental NRC safety standards and DOD weapon systems and many activities in the Department of Energy; (3) Impacts to update the contents of text books of physics and mathematics of all levels; (4) Impacts to the scientific instruments with applications in high technologies. The importance of Trajectory Solid Angle can be quoted from a letter by the late Institute Professor P. M. Morse of MIT who reviewed the DOE proposal P7900450 (reference No. 7) in 1979 and addressed to the inventor. 'If the Trajectory Solid Angle is correct it will provide a revolutionary concept in physics'. (authors)
Impact Angle Control of Interplanetary Shock Geoeffectiveness: A Statistical Study
Oliveira, D M
2015-01-01
We present a survey of interplanetary (IP) shocks using WIND and ACE satellite data from January 1995 to December 2013 to study how IP shock geoeffectiveness is controlled by IP shock impact angles. A shock list covering one and a half solar cycle is compiled. The yearly number of IP shocks is found to correlate well with the monthly sunspot number. We use data from SuperMAG, a large chain with more than 300 geomagnetic stations, to study geoeffectiveness triggered by IP shocks. The SuperMAG SML index, an enhanced version of the familiar AL index, is used in our statistical analysis. The jumps of the SML index triggered by IP shock impacts on the Earth's magnetosphere is investigated in terms of IP shock orientation and speed. We find that, in general, strong (high speed) and almost frontal (small impact angle) shocks are more geoeffective than inclined shocks with low speed. The strongest correlation (correlation coefficient R = 0.70) occurs for fixed IP shock speed and varying the IP shock impact angle. We ...
Precise Measurements of Beam Spin Asymmetries in Semi-Inclusive ?0 production
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aghasyan, M.; Avakian, H.; Rossi, P.; De Sanctis, E.; Hasch, D.; Mirazita, M.; Adikaram, D.; Amaryan, M. J.; Anghinolfi, M.; Baghdasaryan, H.; et al
2011-10-01
We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial sin ?h amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle ?h of the produced neutral pion. The dependence of this amplitude on Bjorken x and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.
Sum rule for the backward spin polarizability of the nucleon from a backward dispersion relation
A. I. L'vov; A. M. Nathan
1998-07-09
A new sum rule for $\\gamma_\\pi$, the backward spin polarizability of the nucleon, is derived from a backward-angle dispersion relation. Taking into account single- and multi-pion photoproduction in the s-channel up to the energy 1.5 GeV and resonances in the t-channel with mass below 1.5 GeV, it is found for the proton and neutron that $[\\gamma_\\pi]_p$ = -39.5 +/- 2.4 and $[\\gamma_\\pi]_n$ = 52.5 +/- 2.4, respectively, in units of 10^{-4} fm^4.
Flipping Photoelectron Spins in Topological Insulators
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and photoelectron spin opens a wide range of possibilities for TIs. Strengthening Spintronics The ability to shine polarized light on a topological insulator (TI) and excite...
Flipping Photoelectron Spins in Topological Insulators
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Spins in Topological Insulators Print Inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science. This new phase of...
Flipping Photoelectron Spins in Topological Insulators
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Flipping Photoelectron Spins in Topological Insulators Print Inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science....
Spin Physics Program at RHIC-PHENIX
K. Aoki; for the PHENIX Collaboration
2007-09-03
Longitudinal spin physics program at RHIC-PHENIX is introduced. Recent results of pi0 cross section and A_LL are presented and discussed.
Top Quark Spin Correlations at the Tevatron
Head, Tim; /Manchester U.
2010-07-01
Recent measurements of the correlation between the spin of the top and the spin of the anti-top quark produced in proton anti-proton scattering at a center of mass energy of {radical}s = 1.96 Tev by the CDF and D0 collaborations are discussed. using up to 4.3 fb{sup -1} of data taken with the CDF and D0 detectors the spin correlation parameter C, the degree to which the spins are correlated, is measured in dileptonic and semileptonic final states. The measurements are found to be in agreement with Standard Model predictions.
Spin caloritronics in graphene with Mn
Torres, Alberto Lima, Matheus P. Fazzio, A.; Silva, Antônio J. R. da
2014-02-17
We show that graphene with Mn adatoms trapped at single vacancies features spin-dependent Seebeck effect, thus enabling the use of this material for spin caloritronics. A gate potential can be used to tune its thermoelectric properties in a way it presents either a total spin polarized current, flowing in one given direction, or currents for both spins flowing in opposite directions without net charge transport. Moreover, we show that the thermal magnetoresistance can be tuned between ?100% and +100% by varying a gate potential.
Spatially Separated Spin Carriers in Spin-Semiconducting Graphene Nanoribbons Z. F. Wang,1
Simons, Jack
a transverse electrical field, the sawtooth graphene nanoribbons become a spin semiconductor whose chargeSpatially Separated Spin Carriers in Spin-Semiconducting Graphene Nanoribbons Z. F. Wang,1 Shuo Jin May 2013; published 29 August 2013) A graphene nanoribbon with sawtooth edges has a ferromagnetic
Time-optimal polarization transfer from an electron spin to a nuclear spin
Haidong Yuan; Robert Zeier; Nikolas Pomplun; Steffen J. Glaser; Navin Khaneja
2015-09-07
Polarization transfers from an electron spin to a nuclear spin are essential for various physical tasks, such as dynamic nuclear polarization in nuclear magnetic resonance and quantum state transformations on hybrid electron-nuclear spin systems. We present time-optimal schemes for electron-nuclear polarization transfers which improve on conventional approaches and will have wide applications.
Simulation of multilevel cell spin transfer switching in a full-Heusler alloy spin-valve nanopillar
Chen, Long-Qing
Simulation of multilevel cell spin transfer switching in a full-Heusler alloy spin-valve nanopillar of multilevel cell spin transfer switching in a full-Heusler alloy spin-valve nanopillar H. B. Huang,1,2 X. Q January 2013; published online 29 January 2013) A multilevel cell spin transfer switching process
Saikin, Semion
Single-electron spin decoherence by nuclear spin bath: Linked-cluster expansion approach S. K develop a theory for decoherence dynamics of a single-electron spin interacting with a nuclear spin bath. The approach yields a simple diagrammatic representation and analytical expressions of different nuclear spin
Skinner, T. D.; Olejnik, K.; Cunningham, L. K.; Kurebayashi, H.; Campion, R. P.; Gallagher, B. L.; Jungwirth, T.; Ferguson, A. J.
2015-03-31
spin Hall effect3 (SHE) is absorbed in the ferromagnet and induces the spin transfer torque4 (STT). In the other pic- ture, a non-equilibrium spin-density is generated via the relativistic inverse spin galvanic effect5 (ISGE) and induces the spin...
Spinning Reserve from Responsive Load
Kueck, John D; Kirby, Brendan J; Laughner, T; Morris, K
2009-01-01
As power system costs rise and capacity is strained demand response can provide a significant system reliability benefit at a potentially attractive cost. The 162 room Music Road Hotel in Pigeon Forge Tennessee agreed to host a spinning reserve test. The Tennessee Valley Authority (TVA) supplied real-time metering and monitoring expertise to record total hotel load during both normal operations and testing. Preliminary testing showed that hotel load can be curtailed by 22% to 37% depending on the outdoor temperature and the time of day. The load drop was very rapid, essentially as fast as the 2 second metering could detect.
Coherent control of dipolar coupled spins in large Hilbert spaces
Sinha, Suddhasattwa
2006-01-01
Controlling the dynamics of a dipolar-coupled spin system is critical to the development of solid-state spin-based quantum information processors. Such control remains challenging, as every spin is coupled to a large number ...
Europium oxide as a perfect electron spin filter
Santos, Tiffany S. (Tiffany Suzanne), 1980-
2007-01-01
Essential to the emergence of spin-based electronics is a source of highly polarized electron spins. Conventional ferromagnets have at best a spin polarization P-50%. Europium monoxide is a novel material capable of ...
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
From October 2012 through September 2013, the second ARM Mobile Facility (AMF2) was deployed on the container ship Spirit, operated by Horizon Lines, for the Marine ARM GPCI* Investigation of Clouds (MAGIC) field campaign. During approximately 20 round trips between Los Angeles, California, and Honolulu, Hawaii, AMF2 obtained continuous on-board measurements of cloud and precipitation, aerosols, and atmospheric radiation; surface meteorological and oceanographic variables; and atmospheric profiles from weather balloons launched every six hours. During two two-week intensive observational periods in January and July 2013, additional instruments were deployed and balloon soundings were be increased to every three hours. These additional data provided a more detailed characterization of the state of the atmosphere and its daily cycle during two distinctly different seasons. The primary objective of MAGIC was to improve the representation of the stratocumulus-to-cumulus transition in climate models. AMF2 data documented the small-scale physical processes associated with turbulence, convection, and radiation in a variety of marine cloud types.
Hysteretic Optimization For Spin Glasses
B. Goncalves; S. Boettcher
2007-12-10
The recently proposed Hysteretic Optimization (HO) procedure is applied to the 1D Ising spin chain with long range interactions. To study its effectiveness, the quality of ground state energies found as a function of the distance dependence exponent, $\\sigma$, is assessed. It is found that the transition from an infinite-range to a long-range interaction at $\\sigma=0.5$ is accompanied by a sharp decrease in the performance . The transition is signaled by a change in the scaling behavior of the average avalanche size observed during the hysteresis process. This indicates that HO requires the system to be infinite-range, with a high degree of interconnectivity between variables leading to large avalanches, in order to function properly. An analysis of the way auto-correlations evolve during the optimization procedure confirm that the search of phase space is less efficient, with the system becoming effectively stuck in suboptimal configurations much earlier. These observations explain the poor performance that HO obtained for the Edwards-Anderson spin glass on finite-dimensional lattices, and suggest that its usefulness might be limited in many combinatorial optimization problems.
Single-parameter spin-pumping in driven metallic rings with spin-orbit coupling
Ramos, J. P.; Apel, V. M.; Foa Torres, L. E. F.; Orellana, P. A.
2014-03-28
We consider the generation of a pure spin-current at zero bias voltage with a single time-dependent potential. To such end we study a device made of a mesoscopic ring connected to electrodes and clarify the interplay between a magnetic flux, spin-orbit coupling, and non-adiabatic driving in the production of a spin and electrical current. By using Floquet theory, we show that the generated spin to charge current ratio can be controlled by tuning the spin-orbit coupling.
Electron beams of cylindrically symmetric spin polarization
Yan Wang; Chun-Fang Li
2011-04-24
Cylindrically symmetric electron beams in spin polarization are reported for the first time. They are shown to be the eigen states of total angular momentum in the $z$ direction. But they are neither the eigen states of spin nor the eigen states of orbital angular momentum in that direction.
Spacetime Warps for Spinning Particles Possible?
T. Dudas
2002-01-04
By incorporating spinning particles into the framework of classical General Relativity, the theory is changed insofar, as, though using holonome coordinates, the connexion becomes asymmetrical. This implies, that partial derivatives do not commute any longer. Hence, the class of functions under consideration has to be extended. A non-minimal extension leads to the possibility of spacetime warps for spinning particles.
Tidal deformations of a spinning compact object
Paolo Pani; Leonardo Gualtieri; Andrea Maselli; Valeria Ferrari
2015-06-30
The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole moments of the central object, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.
Heterostructure unipolar spin transistors M. E. Flatta
Flatte, Michael E.
of integrating the nonvolatility of metallic magnetoelectronics with the gain properties of semiconductor charge12 have been proposed, although the desired material properties needed for these devices have yet semiconductor electronics and spin-based unipolar electronics by considering unipolar spin transistors
Spin Transport in non-inertial frame
Chowdhury, Debashree
2014-01-01
The influence of acceleration and rotation on spintronic applications is theoretically investigated. In our formulation, considering a Dirac particle in a non-inertial frame, different spin related aspects are studied. The spin current appearing due to the inertial spin-orbit coupling (SOC) is enhanced by the interband mixing of the conduction and valence band states. Importantly, one can achieve a large spin current through the $\\vec{k}. \\vec{p}$ method in this non-inertial frame. Furthermore, apart from the inertial SOC term due to acceleration, for a particular choice of the rotation frequency, a new kind of SOC term can be obtained from the spin rotation coupling (SRC). This new kind of SOC is of Dresselhaus type and controllable through the rotation frequency. In the field of spintronic applications, utilizing the inertial SOC and SRC induced SOC term, theoretical proposals for the inertial spin filter, inertial spin galvanic effect are demonstrated. Finally, one can tune the spin relaxation time in semi...
Nuclear spin-density wave theory
Yao Cheng
2009-09-15
Recently [arXiv:0906.5417], we reported a quantum phase transition of 103mRh excited by bremsstrahlung pumping. The long-lived Moessbauer excitation is delocalized as a neutral quasiparticle carrying a spin current. This letter gives a general theory for a nuclear spin-density wave propagating on crystals consisting of identical nuclei with a multipolar transition.
Sherman, EY; Sinova, Jairo.
2005-01-01
spin-field-effect transistor in the diffusive regime possible. We demonstrate that the spin relaxation through the randomness of spin-orbit coupling imposes important physical limitations on the operational properties of these devices....
Influence of Topological Spin Fluctuations on Charge Transport
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Influence of Topological Spin Fluctuations on Charge Transport Influence of Topological Spin Fluctuations on Charge Transport Print Wednesday, 27 April 2005 00:00 Layered...
Theoretical Overview on Recent Developments in Transverse Spin Physics
Yuan, Feng
2009-01-01
reviews on these exciting developments in this physics. Thisthat the transverse spin physics is playing a very importantin the strong interaction physics for hadronic spin physics.
Engineering Nuclear spin has now been associated with Nobel Prizes
Chemical Engineering Nuclear spin has now been associated with Nobel Prizes in Physics, Chemistry, 2013). seminar NMR: Spin without the Politics Dr. Jeffrey A. Reimer Chemical & Biomolecular Engineering
Information storage capacity of discrete spin systems
Beni Yoshida
2012-12-24
Understanding the limits imposed on information storage capacity of physical systems is a problem of fundamental and practical importance which bridges physics and information science. There is a well-known upper bound on the amount of information that can be stored reliably in a given volume of discrete spin systems which are supported by gapped local Hamiltonians. However, all the previously known systems were far below this theoretical bound, and it remained open whether there exists a gapped spin system that saturates this bound. Here, we present a construction of spin systems which saturate this theoretical limit asymptotically by borrowing an idea from fractal properties arising in the Sierpinski triangle. Our construction provides not only the best classical error-correcting code which is physically realizable as the energy ground space of gapped frustration-free Hamiltonians, but also a new research avenue for correlated spin phases with fractal spin configurations.
Swing switching of spin-torque valves
Tom Dunn; Alex Kamenev
2012-10-10
We propose a method for inducing magnetization reversal using an AC spin current polarized perpendicular to the equilibrium magnetization of the free magnetic layer. We show that the critical AC spin current is significantly smaller than the corresponding DC one. The effect is understood as a consequence of the underdamped nature of the spin-torque oscillators. It allows to use the kinetic inertia to overcome the residual energy barrier, rather than suppressing the latter by a large spin current. The effect is similar to a swing which may be set into high amplitude motion by a weak near-resonant push. The optimal AC frequency is identified as the upper bifurcation frequency of the corresponding driven nonlinear oscillator. Together with fast switching times it makes the perpendicular AC method to be the most efficient way to realize spin-torque memory valve.
Electric field induced spin-polarized current
Murakami, Shuichi; Nagaosa, Naoto; Zhang, Shoucheng
2006-05-02
A device and a method for generating an electric-field-induced spin current are disclosed. A highly spin-polarized electric current is generated using a semiconductor structure and an applied electric field across the semiconductor structure. The semiconductor structure can be a hole-doped semiconductor having finite or zero bandgap or an undoped semiconductor of zero bandgap. In one embodiment, a device for injecting spin-polarized current into a current output terminal includes a semiconductor structure including first and second electrodes, along a first axis, receiving an applied electric field and a third electrode, along a direction perpendicular to the first axis, providing the spin-polarized current. The semiconductor structure includes a semiconductor material whose spin orbit coupling energy is greater than room temperature (300 Kelvin) times the Boltzmann constant. In one embodiment, the semiconductor structure is a hole-doped semiconductor structure, such as a p-type GaAs semiconductor layer.
Asymmetric domain walls of small angle in soft ferromagnetic films
Lukas Döring; Radu Ignat
2014-12-07
We focus on a special type of domain walls appearing in the Landau-Lifshitz theory for soft ferromagnetic films. These domain walls are divergence-free $S^2$-valued transition layers that connect two directions in $S^2$ (differing by an angle $2\\theta$) and minimize the Dirichlet energy. Our main result is the rigorous derivation of the asymptotic structure and energy of such "asymmetric" domain walls in the limit $\\theta \\to 0$. As an application, we deduce that a supercritical bifurcation causes the transition from symmetric to asymmetric walls in the full micromagnetic model.
Mira, an angle shot | Argonne Leadership Computing Facility
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGE OFDetectionBenchmarkResultsperi DOElEIA - 00356Miraan angle
Jozwiak, Chris M.; Graff, Jeff; Lebedev, Gennadi; Andresen, Nord; Schmid, Andreas; Fedorov, Alexei; El Gabaly, Farid; Wan, Weishi; Lanzara, Alessandra; Hussain, Zahid
2010-04-13
We describe a spin-resolved electron spectrometer capable of uniquely efficient and high energy resolution measurements. Spin analysis is obtained through polarimetry based on low-energy exchange scattering from a ferromagnetic thin-film target. This approach can achieve a similar analyzing power (Sherman function) as state-of-the-art Mott scattering polarimeters, but with as much as 100 times improved efficiency due to increased reflectivity. Performance is further enhanced by integrating the polarimeter into a time-of-flight (TOF) based energy analysis scheme with a precise and flexible electrostatic lens system. The parallel acquisition of a range of electron kinetic energies afforded by the TOF approach results in an order of magnitude (or more) increase in efficiency compared to hemispherical analyzers. The lens system additionally features a 90 degrees bandpass filter, which by removing unwanted parts of the photoelectron distribution allows the TOF technique to be performed at low electron drift energy and high energy resolution within a wide range of experimental parameters. The spectrometer is ideally suited for high-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES), and initial results are shown. The TOF approach makes the spectrometer especially ideal for time-resolved spin-ARPES experiments.
Quantum Decoherence of the Central Spin in a Sparse System of Dipolar Coupled Spins
Wayne M. Witzel; Malcolm S. Carroll; Lukasz Cywinski; S. Das Sarma
2012-08-02
The central spin decoherence problem has been researched for over 50 years in the context of both nuclear magnetic resonance and electron spin resonance. Until recently, theoretical models have employed phenomenological stochastic descriptions of the bath-induced noise. During the last few years, cluster expansion methods have provided a microscopic, quantum theory to study the spectral diffusion of a central spin. These methods have proven to be very accurate and efficient for problems of nuclear-induced electron spin decoherence in which hyperfine interactions with the central electron spin are much stronger than dipolar interactions among the nuclei. We provide an in-depth study of central spin decoherence for a canonical scale-invariant all-dipolar spin system. We show how cluster methods may be adapted to treat this problem in which central and bath spin interactions are of comparable strength. Our extensive numerical work shows that a properly modified cluster theory is convergent for this problem even as simple perturbative arguments begin to break down. By treating clusters in the presence of energy detunings due to the long-range (diagonal) dipolar interactions of the surrounding environment and carefully averaging the effects over different spin states, we find that the nontrivial flip-flop dynamics among the spins becomes effectively localized by disorder in the energy splittings of the spins. This localization effect allows for a robust calculation of the spin echo signal in a dipolarly coupled bath of spins of the same kind, while considering clusters of no more than 6 spins. We connect these microscopic calculation results to the existing stochastic models. We, furthermore, present calculations for a series of related problems of interest for candidate solid state quantum bits including donors and quantum dots in silicon as well as nitrogen-vacancy centers in diamond.
High-harmonic XUV source for time- and angle-resolved photoemission...
Office of Scientific and Technical Information (OSTI)
High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy Citation Details In-Document Search Title: High-harmonic XUV source for time- and angle-resolved...
Small-Angle X-Ray Scattering From RNA, Proteins, And Protein...
Office of Scientific and Technical Information (OSTI)
Small-Angle X-Ray Scattering From RNA, Proteins, And Protein Complexes Citation Details In-Document Search Title: Small-Angle X-Ray Scattering From RNA, Proteins, And Protein...
Dependence of the intrinsic spin-Hall effect on spin-orbit interaction character RID B-5617-2009
Nomura, K.; Sinova, Jairo; Sinitsyn, NA; MacDonald, AH.
2005-01-01
We report on a comparative numerical study of the spin-Hall conductivity in two dimensions for three different spin-orbit interaction models
G$^0$ Electronics and Data Acquisition (Forward-Angle Measurements)
D. Marchand; J. Arvieux; L. Bimbot; A. Biselli; J. Bouvier; H. Breuer; R. Clark; J. -C. Cuzon; M. Engrand; R. Foglio; C. Furget; X. Grave; B. Guillon; H. Guler; P. M. King; S. Kox; J. Kuhn; Y. Ky; J. Lachniet; J. Lenoble; E. Liatard; J. Liu; E. Munoz; J. Pouxe; G. Quéméner; B. Quinn; J. -S. Réal; O. Rossetto; R. Sellem
2007-03-15
The G$^0$ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for $\\vec{e}p$ elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G$^0$ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G$^0$ forward-angle measurements.
Flavor instabilities in the multi-angle neutrino line model
Abbar, Sajad; Shalgar, Shashank
2015-01-01
Neutrino flavor oscillations in the presence of ambient neutrinos is nonlinear in nature which leads to interesting phenomenology that has not been well understood. It was recently shown that, in the two-dimensional, two-beam neutrino Line model, the inhomogeneous neutrino oscillation modes on small distance scales can become unstable at larger neutrino densities than the homogeneous mode does. We develop a numerical code to solve neutrino oscillations in the multi-angle/beam Line model with a continuous neutrino angular distribution. We show that the inhomogeneous oscillation modes can occur at even higher neutrino densities in the multi-angle model than in the two-beam model. We also find that the inhomogeneous modes on sufficiently small scales can be unstable at smaller neutrino densities with ambient matter than without, although a larger matter density does shift the instability region of the homogeneous mode to higher neutrino densities in the Line model as it does in the one-dimensional supernova Bulb...
Statistical mechanics of nonequilibrium systems of rotators with alternated spins
Andrey Dymov
2014-12-22
We consider a finite region of a d-dimensional lattice of nonlinear Hamiltonian rotators, where neighbouring rotators have opposite spins and are coupled by a small potential of order $\\varepsilon^a,\\, a\\geq1/2$. We weakly stochastically perturb the system in such a way that each rotator interacts with its own stochastic Langevin-type thermostat with a force of order $\\varepsilon$. Then we introduce the action-angle variables for the system of uncoupled rotators ($\\varepsilon=0$) and note that the sum of actions over all nodes is conserved by the purely Hamiltonian dynamics of the system with $\\varepsilon>0$. We investigate the limiting (as $\\varepsilon \\rightarrow 0$) dynamics of actions for solutions of the $\\varepsilon$-perturbed system on time intervals of order $\\varepsilon^{-1}$. It turns out that the limiting dynamics is governed by a certain autonomous (stochastic) equation for the vector of actions. This equation has a completely non-Hamiltonian nature. The $\\varepsilon$-perturbed system has a unique stationary measure $\\widetilde \\mu^\\varepsilon$ and is mixing. Any limiting point of the family $\\{\\widetilde \\mu^\\varepsilon\\}$ of stationary measures as $\\varepsilon\\rightarrow 0$ is an invariant measure of the system of uncoupled integrable rotators. There are plenty of such measures. However, it turns out that only one of them describes the limiting dynamics of the $\\varepsilon$-perturbed system: we prove that a limiting point of $\\{\\widetilde\\mu^\\varepsilon\\}$ is unique, its projection to the space of actions is the unique stationary measure of the autonomous equation above, which turns out to be mixing, and its projection to the space of angles is the normalized Lebesque measure on the torus $\\mathbb{T}^N$. Most of results and convergences we obtain are uniform in the number $N$ of rotators.
Annual Logging Symposium, June 3-6, 2007 QUANTITATIVE STUDIES OF RELATIVE DIP ANGLE AND BED -
Torres-Verdín, Carlos
AND BED - THICKNESS EFFECTS ON LWD DENSITY IMAGES ACQUIRED IN HIGH-ANGLE AND HORIZONTAL WELLS E.A. Uzoh, A (LWD) density images acquired in high-angle and horizontal (HA/HZ) wells can reveal much about to quantify the influence of relative dip angle and bed thickness on LWD density images acquired in HA
Isotropic scattering and crustal imaging with wide-angle prestack migration
. The depth migration method I use is a backprojection of assumed primary re ection amplitudes into a depth34 Chapter 3 Isotropic scattering and crustal imaging with wide-angle prestack migration 3-angle prestack migration of earthquake recordings. #12;35 3.2 Crustal imaging method 3.2.1 Wide-angle prestack
Rotation Angle for the Optimum Tracking of One-Axis Trackers
Marion, W. F.; Dobos, A. P.
2013-07-01
An equation for the rotation angle for optimum tracking of one-axis trackers is derived along with equations giving the relationships between the rotation angle and the surface tilt and azimuth angles. These equations are useful for improved modeling of the solar radiation available to a collector with tracking constraints and for determining the appropriate motor revolutions for optimum tracking.
Design of angle-tolerant multivariate optical elements for chemical imaging
Myrick, Michael Lenn
Design of angle-tolerant multivariate optical elements for chemical imaging Olusola O. Soyemi in imaging applications. We report a method for the design of angle-insensitive MOEs based on modification of Bismarck Brown and Crystal Violet, was designed and its performance simulated. For angles of incidence
Coherent Flow Structures and Suspension Events over Low-angle Dunes: Fraser River,
Venditti, Jeremy G.
Coherent Flow Structures and Suspension Events over Low-angle Dunes: Fraser River, Canada by Ryan) Title of Thesis: Coherent Flow Structures and Suspension Events over Low-angle Dunes: Fraser River Licence #12;iv Abstract It is increasingly obvious that dunes with low-angle lee-sides (
Wide Viewing Angle Multi-domain In-Plane Switching LCD
Wu, Shin-Tson
15 [10,11]. In this paper, we investigate the bending angle effect on a MD IPS using the chevron The bending angle effect on a multi-domain in-plane switching liquid crystal display (MD IPS LCD) using the bending angle of the electrodes increases from 10 to 40 , the threshold voltage is lowered from 1.25 Vrms
hal-00154048,version1-12Jun2007 The new very small angle neutron scattering
Boyer, Edmond
hal-00154048,version1-12Jun2007 The new very small angle neutron scattering spectrometer The design and characteristics of the new very small angle neutron scattering spectrometer under construction in order to fill the gap between light scattering and classical small angle neutron scattering (SANS
Molecular dynamics simulation of the contact angle of liquids on solid surfaces
Zhigilei, Leonid V.
angle is studied as a function of system temperature and the solid/fluid interaction potential. It is shown that the contact angle decreases with increasing system temperature and increases when the potential decreases. At high system temperature pressure , the contact angle drops to zero. The predictions
Controllable spin polarization and spin filtering in a zigzag silicene nanoribbon
Farokhnezhad, Mohsen Esmaeilzadeh, Mahdi Pournaghavi, Nezhat; Ahmadi, Somaieh
2015-05-07
Using non-equilibrium Green's function, we study the spin-dependent electron transport properties in a zigzag silicene nanoribbon. To produce and control spin polarization, it is assumed that two ferromagnetic strips are deposited on the both edges of the silicene nanoribbon and an electric field is perpendicularly applied to the nanoribbon plane. The spin polarization is studied for both parallel and anti-parallel configurations of exchange magnetic fields induced by the ferromagnetic strips. We find that complete spin polarization can take place in the presence of perpendicular electric field for anti-parallel configuration and the nanoribbon can work as a perfect spin filter. The spin direction of transmitted electrons can be easily changed from up to down and vice versa by reversing the electric field direction. For parallel configuration, perfect spin filtering can occur even in the absence of electric field. In this case, the spin direction can be changed by changing the electron energy. Finally, we investigate the effects of nonmagnetic Anderson disorder on spin dependent conductance and find that the perfect spin filtering properties of nanoribbon are destroyed by strong disorder, but the nanoribbon retains these properties in the presence of weak disorder.
Cross-correlation spin noise spectroscopy of heterogeneous interacting spin systems
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Roy, Dibyendu; Yang, Luyi; Crooker, Scott A.; Sinitsyn, Nikolai A.
2015-04-30
Interacting multi-component spin systems are ubiquitous in nature and in the laboratory. As such, investigations of inter-species spin interactions are of vital importance. Traditionally, they are studied by experimental methods that are necessarily perturbative: e.g., by intentionally polarizing or depolarizing one spin species while detecting the response of the other(s). Here, we describe and demonstrate an alternative approach based on multi-probe spin noise spectroscopy, which can reveal inter-species spin interactions - under conditions of strict thermal equilibrium - by detecting and cross-correlating the stochastic fluctuation signals exhibited by each of the constituent spin species. Specifically, we consider a two-component spinmore »ensemble that interacts via exchange coupling, and we determine cross-correlations between their intrinsic spin fluctuations. The model is experimentally confirmed using “two-color” optical spin noise spectroscopy on a mixture of interacting Rb and Cs vapors. Noise correlations directly reveal the presence of inter-species spin exchange, without ever perturbing the system away from thermal equilibrium. These non-invasive and noise-based techniques should be generally applicable to any heterogeneous spin system in which the fluctuations of the constituent components are detectable.« less
Instantons As Unitary Spin Maker
Napsuciale, M; Kirchbach, M; Napsuciale, Mauro; Wirzba, Andreas; Kirchbach, Mariana
2002-01-01
The instanton-induced determinantal 't Hooft interaction is built into a three-flavor linear sigma model which is considered in the OZI-rule-respecting basis. The mixing of the strange and non-strange quarkonia, which is due to the presence of instantons in combination with the spontaneous breaking of chiral symmetry, is shown to be ideal thus leading to the formation of an octet-flavor state. We study the impact of 't Hooft's interaction on the eta NN coupling finding the usual SU(3) results for this coupling, however, with possible generalizations to non-ideal mixing angles and different values of the meson decay constants in the strange and non-strange sectors, respectively.
Controlling spin relaxation with a cavity
A. Bienfait; J. J. Pla; Y. Kubo; X. Zhou; M. Stern; C. C. Lo; C. D. Weis; T. Schenkel; D. Vion; D. Esteve; J. J. L. Morton; P. Bertet
2015-08-27
Spontaneous emission of radiation is one of the fundamental mechanisms by which an excited quantum system returns to equilibrium. For spins, however, spontaneous emission is generally negligible compared to other non-radiative relaxation processes because of the weak coupling between the magnetic dipole and the electromagnetic field. In 1946, Purcell realized that the spontaneous emission rate can be strongly enhanced by placing the quantum system in a resonant cavity -an effect which has since been used extensively to control the lifetime of atoms and semiconducting heterostructures coupled to microwave or optical cavities, underpinning single-photon sources. Here we report the first application of these ideas to spins in solids. By coupling donor spins in silicon to a superconducting microwave cavity of high quality factor and small mode volume, we reach for the first time the regime where spontaneous emission constitutes the dominant spin relaxation mechanism. The relaxation rate is increased by three orders of magnitude when the spins are tuned to the cavity resonance, showing that energy relaxation can be engineered and controlled on-demand. Our results provide a novel and general way to initialise spin systems into their ground state, with applications in magnetic resonance and quantum information processing. They also demonstrate that, contrary to popular belief, the coupling between the magnetic dipole of a spin and the electromagnetic field can be enhanced up to the point where quantum fluctuations have a dramatic effect on the spin dynamics; as such our work represents an important step towards the coherent magnetic coupling of individual spins to microwave photons.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zachariou, N.; Ilieva, Y.; Ivanov, N. Ya.; Sargsian, M. M.; Avakian, R.; Feldman, G.; Nadel-Turonski, P.
2015-05-01
The beam-spin asymmetry, ?, for the reaction ?d???pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, ?c.m., between 25° and 160°. These are the first measurements of beam-spin asymmetries at ?c.m.=90° for photon-beam energies above 1.6 GeV, and the first measurements for angles other than ?c.m.=90°. The angular and energy dependence of ? is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition regionmore »between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.« less
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zachariou, Nicholas; et. al.,
2015-05-01
The beam-spin asymmetry, Sigma, for the reaction ?d-->pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, thetac.m., between 25degrees and 160degrees. These are the first measurements of beam-spin asymmetries at thetac.m.=90degrees for photon-beam energies above 1.6 GeV, and the first measurements for angles other than thetac.m.=90degrees. The angular and energy dependence of Sigma is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition regionmore »between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.« less
Zachariou, Nicholas; Ivanov, Nikolay Ya; Sargsian, Misak M; Avakian, Robert; Feldman, Gerald; Nadel-Turonski, Pawel; Adhikari, K P; Adikaram, D; Anderson, M D; Pereira, S Anefalos; Avakian, H; Badui, R A; Baltzell, N A; Battaglieri, M; Baturin, V; Bedlinskiy, I; Biselli, A S; Briscoe, W J; Brooks, W K; Burkert, V D; Cao, T; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Compton, N; Contalbrigo, M; Cortes, O; Crede, V; D'Angelo, A; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Forest, T A; Fradi, A; Gevorgyan, N; Ghandilyan, Y; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Glazier, D I; Golovatch, E; Gothe, R W; Griffioen, K A; Guidal, M; Hafidi, K; Hanretty, C; Harrison, N; Hattawy, M; Hicks, K; Ho, D; Holtrop, M; Hughes, S M; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jiang, H; Jo, H S; Joo, K; Keller, D; Khachatryan, G; Khandaker, M; Kim, A; Kim, W; Klein, F J; Kubarovsky, V; Lenisa, P; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mattione, P T; McKinnon, B; Mineeva, T; Mirazita, M; Mokeeev, V I; Montgomery, R A; Moutarde, H; Camacho, C Munoz; Net, L A; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Phelps, W; Phillips, J J; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Puckett, A J R; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Senderovich, I; Sharabian, Y G; Skorodumina, Iu; Smith, G D; Sober, D I; Sokhan, D; Sparveris, N; Stepanyan, S; Strauch, S; Sytnik, V; Taiuti, M; Tian, Ye; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K; Watts, D; Wei, X; Wood, M H; Zana, L; Zhang, J; Zhao, Z W; Zonta, I
2015-01-01
The beam-spin asymmetry, $\\Sigma$, for the reaction $\\gamma d\\rightarrow pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, $\\theta_{c.m.}$, between $25^\\circ$ and $160^\\circ$. These are the first measurements of beam-spin asymmetries at $\\theta_{c.m.}=90^\\circ$ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than $\\theta_{c.m.}=90^\\circ$. The angular and energy dependence of $\\Sigma$ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.
Nicholas Zachariou; Yordanka Ilieva; Nikolay Ya. Ivanov; Misak M Sargsian; Robert Avakian; Gerald Feldman; Pawel Nadel-Turonski; K. P. Adhikari; D. Adikaram; M. D. Anderson; S. Anefalos Pereira; H. Avakian; R. A. Badui; N. A. Baltzell; M. Battaglieri; V. Baturin; I. Bedlinskiy; A. S. Biselli; W. J. Briscoe; W. K. Brooks; V. D. Burkert; T. Cao; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; L. Colaneri; P. L. Cole; N. Compton; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; G. Fedotov; S. Fegan; A. Filippi; J. A. Fleming; T. A. Forest; A. Fradi; N. Gevorgyan; Y. Ghandilyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; D. I. Glazier; E. Golovatch; R. W. Gothe; K. A. Griffioen; M. Guidal; K. Hafidi; C. Hanretty; N. Harrison; M. Hattawy; K. Hicks; D. Ho; M. Holtrop; S. M. Hughes; D. G. Ireland; B. S. Ishkhanov; E. L. Isupov; H. Jiang; H. S. Jo; K. Joo; D. Keller; G. Khachatryan; M. Khandaker; A. Kim; W. Kim; F. J. Klein; V. Kubarovsky; P. Lenisa; K. Livingston; H. Y. Lu; I . J . D. MacGregor; N. Markov; P. T. Mattione; B. McKinnon; T. Mineeva; M. Mirazita; V. I. Mokeeev; R. A. Montgomery; H. Moutarde; C. Munoz Camacho; L. A. Net; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A. I. Ostrovidov; K. Park; E. Pasyuk; W. Phelps; J. J. Phillips; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; Y. Prok; D. Protopopescu; A. J. R. Puckett; M. Ripani; A. Rizzo; G. Rosner; P. Rossi; P. Roy; F. Sabatié; C. Salgado; D. Schott; R. A. Schumacher; E. Seder; I. Senderovich; Y. G. Sharabian; Iu. Skorodumina; G. D. Smith; D. I. Sober; D. Sokhan; N. Sparveris; S. Stepanyan; S. Strauch; V. Sytnik; M. Taiuti; Ye Tian; M. Ungaro; H. Voskanyan; E. Voutier; N. K. Walford; D. Watts; X. Wei; M. H. Wood; L. Zana; J. Zhang; Z. W. Zhao; I. Zonta; for the CLAS collaboration
2015-03-18
The beam-spin asymmetry, $\\Sigma$, for the reaction $\\gamma d\\rightarrow pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, $\\theta_{c.m.}$, between $25^\\circ$ and $160^\\circ$. These are the first measurements of beam-spin asymmetries at $\\theta_{c.m.}=90^\\circ$ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than $\\theta_{c.m.}=90^\\circ$. The angular and energy dependence of $\\Sigma$ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zachariou, Nicholas [University of South Carolina; et. al.,
2015-05-01
The beam-spin asymmetry, Sigma, for the reaction ?d-->pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, thetac.m., between 25degrees and 160degrees. These are the first measurements of beam-spin asymmetries at thetac.m.=90degrees for photon-beam energies above 1.6 GeV, and the first measurements for angles other than thetac.m.=90degrees. The angular and energy dependence of Sigma is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.
Green, Sara
2011-01-01
loudly. A MAN WITH AN OLD FEDORA comes out of one of theThe Man with the Old Fedora comes out of the flower shopup, the Man with the Old Fedora comes out of the grocery
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
with all the changes, the accelerator can be made to work. Beam Since my first serious introduction to nuclear and particle physics - when I worked for a few weeks one summer at...
Spin Glasses: Old and New Complexity
Stein, D. L.
2011-09-22
Spin glasses are disordered magnetic systems that exhibit a variety of properties that are characteristic of 'complex systems'. After a brief review of the systems themselves, I will discuss how spin glass concepts have found use in and, in some cases, further advanced areas such as computer science, biology, and other fields: what one might term 'old complexity'. I will then turn to a discussion of more recent concepts and ideas that have flowed from studies of spin glasses, and using these introduce a proposal for a kind of 'new complexity'.
Nonequilibrium Spin Magnetization Quantum Transport Equations
Buot, F A; Otadoy, R E S; Villarin, D L
2011-01-01
The classical Bloch equations of spin magnetization transport is extended to fully time-dependent and highly-nonlinear nonequilibrium quantum distribution function (QDF) transport equations. The leading terms consist of the Boltzmann kinetic equation with spin-orbit coupling in a magnetic field together with spin-dependent scattering terms which do not have any classical analogue, but should incorporate the spatio-temporal-dependent phase-space dynamics of Elliot-Yafet and D'yakonov-Perel scatterings. The resulting magnetization QDF transport equation serves as a foundation for computational spintronic and nanomagnetic device applications, in performing simulation of ultrafast-switching-speed/low-power performance and reliability analyses.
Dussaux, A.; Rache Salles, B.; Jenkins, A. S.; Bortolotti, P.; Grollier, J.; Cros, V.; Fert, A.; Khvalkovskiy, A. V.; Kubota, H.; Fukushima, A.; Yakushiji, K.; Yuasa, S.
2014-07-14
We investigate the microwave response of a spin transfer vortex based oscillator in a magnetic tunnel junction with an in-plane reference layer combined with a spin valve with an out-of-plane magnetization spin polarizing layer. The main advantage of this perpendicular spin polarizer is to induce a large spin transfer force even at zero magnetic field, thus leading to a record emitted power (up to 0.6??W) associated to a very narrow spectral linewidth of a few hundreds of kHz. The characteristics of this hybrid vortex based spin transfer nano-oscillator obtained at zero field and room temperature are of great importance for applications based on rf spintronic devices as integrated and tunable microwave source and/or microwave detector.
Dynamic control of spin wave spectra using spin-polarized currents
Wang, Qi; Zhang, Huaiwu Tang, Xiaoli; Bai, Feiming; Zhong, Zhiyong; Fangohr, Hans
2014-09-15
We describe a method of controlling the spin wave spectra dynamically in a uniform nanostripe waveguide through spin-polarized currents. A stable periodic magnetization structure is observed when the current flows vertically through the center of nanostripe waveguide. After being excited, the spin wave is transmitted at the sides of the waveguide. Numerical simulations of spin-wave transmission and dispersion curves reveal a single, pronounced band gap. Moreover, the periodic magnetization structure can be turned on and off by the spin-polarized current. The switching process from full rejection to full transmission takes place within less than 3?ns. Thus, this type magnonic waveguide can be utilized for low-dissipation spin wave based filters.
Noncollinear ferromagnetic easy axes in Py/Ru/FeCo/IrMn spin valves induced by oblique deposition
Bueno, T. E. P.; Parreiras, D. E.; Gomes, G. F. M.; Krambrock, K.; Paniago, R. [Departamento de Física, ICEx, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG (Brazil); Michea, S.; Rodríguez-Suárez, R. L. [Centro de Investigación en Nanotecnología y Materiales Avanzados “CIEN-UC,” Pontifícia Universidad Católica de Chile, Casilla 306, Santiago (Chile); Filho, M. S. Araújo; Macedo, W. A. A. [Laboratório de Física Aplicada, Centro de Desenvolvimento da Tecnologia Nuclear, 30123-970 Belo Horizonte, MG (Brazil)
2014-06-16
We present an investigation on the magnetic properties of Py/Ru/FeCo/IrMn spin valves grown by dc magnetron sputtering. The sample fabrication setup has two important features, (i) the five magnetron sputtering sources are placed in a cluster flange 72° from each other, and (ii) each source is tilted with respect to the sample normal. In-plane angular dependence of the ferromagnetic resonance (FMR) was used to obtain the relevant magnetic anisotropies, such as uniaxial and exchange bias fields. The oblique deposition geometry employed has induced non-collinear easy axes of the two ferromagnetic (FM) layers, with high uniaxial field strengths. The symmetry shift of the angular dependence of the FMR resonances of the two FM layers gives us directly the angle between the easy axes of FM{sub 1} (Py) and FM{sub 2} (FeCo), which turned out to be the angle between two adjacent sputtering sources. The observations of the present study suggest that, by combining oblique deposition and appropriate angles of incidence of the deposition flux, the uniaxial (and unidirectional) axes of individual FM layers can be precisely engineered in spin valve fabrication.
Germanium Nanowire Spin-Valve Device (DMR-0819860)
Petta, Jason
Germanium Nanowire Spin-Valve Device (DMR-0819860) E-S Liu, J. Nah, K.Varahramyan, and E. Tutuc (Univ. of Texas at Austin) Figure 1 The spin-valve device comprised of a Ge nanowire bracketed by two in direction, the spin current is suppressed (spin-valve action). An applied magnetic field By is used
Coherent spinor dynamics in a spin-1 Bose condensate
Loss, Daniel
ARTICLES Coherent spinor dynamics in a spin-1 Bose condensate MING-SHIEN CHANG, QISHU QIN, WENXIAN, for example, a BoseEinstein condensate or a degenerate Fermi gas, the phase space accessible to low of coherent spin-changing collisions in a gas of spin-1 bosons. Starting with condensates occupying two spin
Clifford Algebras and Spin Groups Math G4344, Spring 2012
Woit, Peter
Clifford Algebras and Spin Groups Math G4344, Spring 2012 We'll now turn from the general theory construction. The Lie algebras spin(n, R) and so(n, R) are isomorphic, and the complex simple Lie algebra group corresponding to the Lie algebra spin(n, R). It's compact real form is our Spin(n, R). Note
The origin of wide-angle tailed radio galaxies
Irini Sakelliou; Michael R. Merrifield
1999-09-30
To investigate the origins of wide-angle tailed radio sources (WATs), we have compiled a sample of these systems in Abell clusters for which X-ray data exist. Contrary to conventional wisdom, the WATs are found to be significantly displaced from the X-ray centroids of their host clusters. The bends in the WATs' radio jets are found to be oriented preferentially such that they point directly away from or toward the cluster centre, with more of the former than the latter. If this morphology is attributed to ram pressure, then the WATs are on primarily radial orbits, with more approaching the X-ray centroid than receding. There is also some evidence that the in-coming WATs are on average further from the X-ray centroid than the out-going ones. All of these observations strongly support a scenario in which WATs are created in cluster mergers.
Control of Spin Waves in a Thin Film Ferromagnetic Insulator through Interfacial Spin Scattering
of high-power spin waves. DOI: 10.1103/PhysRevLett.107.146602 PACS numbers: 72.25.Ba, 72.25.Mk, 72.25.Rb, 75.30.Ds Spin waves in ferromagnetic films have many unique properties and thereby have potential raise or reduce the power level to which high-power spin-wave pulses saturate due to nonlinear damping
Wake angle for surface gravity waves on a finite depth fluid
Pethiyagoda, Ravindra; Moroney, Timothy J
2015-01-01
Linear water wave theory suggests that wave patterns caused by a steadily moving disturbance are contained within a wedge whose half-angle depends on the depth-based Froude number $F_H$. For the problem of flow past an axisymmetric pressure distribution in a finite-depth channel, we report on the apparent angle of the wake, which is the angle of maximum peaks. For moderately deep channels, the dependence of the apparent wake angle on the Froude number is very different to the wedge angle, and varies smoothly as $F_H$ passes through the critical value $F_H=1$. For shallow water, the two angles tend to follow each other more closely, which leads to very large apparent wake angles for certain regimes.
Singh, Rameswar, E-mail: rameswar.singh@lpp.polytechnique.fr [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India) [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Brunner, S. [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)] [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Ganesh, R. [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India)] [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jenko, F. [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)] [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)
2014-03-15
This paper presents effects of finite ballooning angles on linear ion temperature gradient (ITG) driven mode and associated heat and momentum flux in Gyrokinetic flux tube simulation GENE. It is found that zero ballooning angle is not always the one at which the linear growth rate is maximum. The ITG mode acquires a short wavelength (SW) branch (k{sub ?}?{sub i}?>?1) when growth rates maximized over all ballooning angles are considered. However, the SW branch disappears on reducing temperature gradient showing characteristics of zero ballooning angle SWITG in case of extremely high temperature gradient. Associated heat flux is even with respect to ballooning angle and maximizes at nonzero ballooning angle while the parallel momentum flux is odd with respect to the ballooning angle.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bhatti, Kanwal Preet; El-Khatib, S.; Srivastava, Vijay; James, R. D.; Leighton, C.
2012-04-27
The Heusler-derived multiferroic alloy Ni50–xCoxMn??Sn?? has recently been shown to exhibit, at just above room temperature, a highly reversible martensitic phase transformation with an unusually large magnetization change. In this work the nature of the magnetic ordering above and below this transformation has been studied in detail in the critical composition range x = 6–8 via temperature-dependent (5–600 K) magnetometry and small-angle neutron scattering (SANS). We observe fairly typical paramagnetic to long-range-ordered ferromagnetic phase transitions on cooling to 420–430 K, with the expected critical spin fluctuations, followed by first-order martensitic phase transformations to a nonferromagnetic state below 360–390 K. Themore »static magnetization reveals complex magnetism in this low-temperature nonferromagnetic phase, including a Langevin-like field dependence, distinct spin freezing near 60 K, and significant exchange bias effects, consistent with superparamagnetic blocking of ferromagnetic clusters of nanoscopic dimensions. We demonstrate that these spin clusters, whose existence has been hypothesized in a variety of martensitic alloys exhibiting competition between ferromagnetic and antiferromagnetic exchange interactions, can be directly observed by SANS. The scattering data are consistent with a liquidlike spatial distribution of interacting magnetic clusters with a mean center-to-center spacing of 12 nm. Considering the behavior of the superparmagnetism, cooling-field and temperature-dependent exchange bias, and magnetic SANS, we discuss in detail the physical form and origin of these spin clusters, their intercluster interactions, the nature of the ground-state magnetic ordering in the martensitic phase, and the implications for our understanding of such alloy systems.« less
Spin transport in lateral spin valves and across a metal- insulator transition in V?O? /
Erekhinsky, Mikhail
2013-01-01
Spin valves is a class of spintronic devices that use spinsuch as integrated spintronic circuits in semiconductors [for the development of these spintronic devices. Many device
CONDITIONS OF PASSAGE AND ENTRAPMENT OF TERRESTRIAL PLANETS IN SPIN-ORBIT RESONANCES
Makarov, Valeri V.
2012-06-10
The dynamical evolution of terrestrial planets resembling Mercury in the vicinity of spin-orbit resonances is investigated using comprehensive harmonic expansions of the tidal torque taking into account the frequency-dependent quality factors and Love numbers. The torque equations are integrated numerically with a small step in time, including the oscillating triaxial torque components but neglecting the layered structure of the planet and assuming a zero obliquity. We find that a Mercury-like planet with a current value of orbital eccentricity (0.2056) is always captured in 3:2 resonance. The probability of capture in the higher 2:1 resonance is approximately 0.23. These results are confirmed by a semi-analytical estimation of capture probabilities as functions of eccentricity for both prograde and retrograde evolutions of spin rate. As follows from analysis of equilibrium torques, entrapment in 3:2 resonance is inevitable at eccentricities between 0.2 and 0.41. Considering the phase space parameters at the times of periastron, the range of spin rates and phase angles for which an immediate resonance passage is triggered is very narrow, and yet a planet like Mercury rarely fails to align itself into this state of unstable equilibrium before it traverses 2:1 resonance.
Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Harrison, N.; Ramshaw, B. J.; Shekhter, A.
2015-06-03
The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whosemore »primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport, and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y« less
Spin injection and manipulation in organic semiconductors
Venkataraman, Karthik (Karthik Raman)
2011-01-01
The use of organic semiconductors to enable organic spintronic devices requires the understanding of transport and control of the spin state of the carriers. This thesis deals with the above issue, focusing on the interface ...
Intrinsic Spin-Orbit Interaction in Graphene
B. S. Kandemir
2012-05-03
In graphene, we report the first theoretical demonstration of how the intrinsic spin orbit interaction can be deduced from the theory and how it can be controlled by tuning a uniform magnetic field, and/or by changing the strength of a long range Coulomb like impurity (adatom), as well as gap parameter. In the impurity context, we find that intrinsic spin-orbit interaction energy may be enhanced by increasing the strength of magnetic field and/or by decreasing the band gap mass term. Additionally, it may be strongly enhanced by increasing the impurity strength. Furthermore, from the proposal of Kane and Mele [Phys. Rev. Lett. 95, 226801 (2005)], it was discussed that the pristine graphene has a quantized spin Hall effect regime where the Rashba type spin orbit interaction term is smaller than that of intrinsic one. Our analysis suggest the nonexistence of such a regime in the ground state of flat graphene.
Resolution of the Proton Spin Problem
F. Myhrer; A. W. Thomas
2007-09-24
A number of lines of investigation into the structure of the nucleon have converged to the point where we believe that one has a consistent explanation of the well known proton spin crisis.
Spin effects in single-electron transistors
Granger, Ghislain
2005-01-01
Basic electron transport phenomena observed in single-electron transistors (SETs) are introduced, such as Coulomb-blockade diamonds, inelastic cotunneling thresholds, the spin-1/2 Kondo effect, and Fano interference. With ...
Spin in the Neutron | Jefferson Lab
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
in the Neutron NEWPORT NEWS, Va. - Puzzling out the source of proton and neutron spin is part of the ongoing experimental effort at Jefferson Lab to understand their structure and...
The darkness of spin-0 dark radiation
Marsh, M.C. David
2015-01-01
We show that the scattering of a general spin-0 sector of dark radiation off the pre-recombination thermal plasma results in undetectably small spectral distortions of the Cosmic Microwave Background.
Spin hall effect in paramagnetic thin films
Xu, Huachun
2009-05-15
ferromagnet rod as a spin injector. Process description and various techniques to improve the measurement sensitivity are presented. Measurement results in aluminum, gold and copper are presented in Chapters III, IV and V. Some new experiments are suggested...
Probing the spin-parity of the pentaquark $\\Theta^+$ baryon
Barmin, V V; Curceanu, C; Davidenko, G V; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tarasov, V V
2015-01-01
Using the DIANA data on the charge-exchange reaction K^+n --> pK^0 on a bound neutron, in which the s-channel formation of the pentaquark baryon \\Theta^+(1538) has been observed,we analyze the dependence of the background-subtracted \\Theta^+ --> pK^0 signal on the K^0 emission angle in the pK^0 rest frame. The data are consistent with the angular dependence of a form dW/d\\cos\\Theta_cms ~ (\\cos\\Theta_cms + A)^2 with a positive offset A. This form of the \\cos\\Theta_cms distribution suggests an interference between the \\Theta-mediated p-wave contribution and the nonresonant s-wave contribution to the total amplitude of the charge-exchange reaction. The p-wave nature of the \\Theta-mediated amplitude is consistent with the spin-parity assignment of 1/2^+ for the \\Theta^+ baryon. The selection in \\cos\\Theta_cms based on the observed angular dependence of the \\Theta^+ --> pK^0 signal allows to boost the statistical significance of the signal up to 6.8 standard deviations. \\e
Probing the spin-parity of the pentaquark $?^+$ baryon
DIANA Collaboration; V. V. Barmin; A. E. Asratyan; C. Curceanu; G. V. Davidenko; C. Guaraldo; M. A. Kubantsev; I. F. Larin; V. A. Matveev; V. A. Shebanov; N. N. Shishov; L. I. Sokolov; V. V. Tarasov
2015-08-02
Using the DIANA data on the charge-exchange reaction K^+n --> pK^0 on a bound neutron, in which the s-channel formation of the pentaquark baryon \\Theta^+(1538) has been observed,we analyze the dependence of the background-subtracted \\Theta^+ --> pK^0 signal on the K^0 emission angle in the pK^0 rest frame. The data are consistent with the angular dependence of a form dW/d\\cos\\Theta_cms ~ (\\cos\\Theta_cms + A)^2 with a positive offset A. This form of the \\cos\\Theta_cms distribution suggests an interference between the \\Theta-mediated p-wave contribution and the nonresonant s-wave contribution to the total amplitude of the charge-exchange reaction. The p-wave nature of the \\Theta-mediated amplitude is consistent with the spin-parity assignment of 1/2^+ for the \\Theta^+ baryon. The selection in \\cos\\Theta_cms based on the observed angular dependence of the \\Theta^+ --> pK^0 signal allows to boost the statistical significance of the signal up to 7.1 standard deviations.
Spin Glasses and Frustration Cynthia Olson, Chairman Transverse spin freezing in a-FexZr100x
Ryan, Dominic
Spin Glasses and Frustration Cynthia Olson, Chairman Transverse spin freezing in a-FexZr100x signatures of transverse spin freezing provides a clear confirmation of predictions from numerical models with random isotropic spin freezing and neither net magnetization nor long range order. At lower levels
Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a,
Rosen, Matthew S
Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a: Received 6 January 2012 Revised 14 March 2012 Available online 28 March 2012 Keywords: Nuclear singlet of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field
Electromagnetic and spin polarisabilities in lattice QCD
W. Detmold; B. C. Tiburzi; A. Walker-Loud
2006-10-02
We discuss the extraction of the electromagnetic and spin polarisabilities of nucleons from lattice QCD. We show that the external field method can be used to measure all the electromagnetic and spin polarisabilities including those of charged particles. We then turn to the extrapolations required to connect such calculations to experiment in the context of chiral perturbation theory, finding a strong dependence on the lattice volume and quark masses.
On the exact evaluation of spin networks
Freidel, Laurent; Hnybida, Jeff; Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1
2013-11-15
We introduce a fully coherent spin network amplitude whose expansion generates all SU(2) spin networks associated with a given graph. We then give an explicit evaluation of this amplitude for an arbitrary graph. We show how this coherent amplitude can be obtained from the specialization of a generating functional obtained by the contraction of parametrized intertwiners à la Schwinger. We finally give the explicit evaluation of this generating functional for arbitrary graphs.
Thermal entanglement properties of small spin clusters
Bose, Indrani; Tribedi, Amit [Department of Physics, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata 700 009 (India)
2005-08-15
Exchange interactions in spin systems can give rise to quantum entanglement in the ground and thermal states of the systems. We consider a spin tetramer, with spins of magnitude (1/2), in which the spins interact via nearest-neighbor, diagonal, and four-spin interactions of strength J{sub 1}, J{sub 2}, and K, respectively. The ground- and thermal-state entanglement properties of the tetramer are calculated analytically in the various limiting cases. Both bipartite and multipartite entanglements are considered and a signature of the quantum phase transition (QPT), in terms of the entanglement ratio, is identified. The first-order QPT is accompanied by discontinuities in the nearest-neighbor and diagonal concurrences. The magnetic properties of a S=(1/2) antiferromagnetic polyoxovanadate compound V12 are well explained by tetramers, with J{sub 2}=0, K=0, in which the spins interact via the isotropic Heisenberg exchange interaction Hamiltonian. Treating the magnetic susceptibility {chi} as an entanglement witness (EW), an estimate of the lower bound of the critical entanglement temperature T{sub c} below which entanglement is present in the experimental compound, is determined. Two other cases considered include the symmetric tetramer--i.e., tetrahedron (J{sub 1}=J{sub 2},K=0)--and the symmetric trimer. In both the cases, there is no entanglement between a pair of spins in the thermal state but multipartite entanglement is present. A second EW based on energy provides an estimate of the entanglement temperature T{sub E} below which the thermal state is definitely entangled. This EW detects bipartite entanglement in the case of the tetramer describing a square of spins (the case of V12 ) and multipartite entanglement in the cases of the tetrahedron and symmetric trimer.
Motional Spin Relaxation in Large Electric Fields
Riccardo Schmid; B. Plaster; B. W. Filippone
2008-07-02
We discuss the precession of spin-polarized Ultra Cold Neutrons (UCN) and $^{3}$He atoms in uniform and static magnetic and electric fields and calculate the spin relaxation effects from motional $v\\times E$ magnetic fields. Particle motion in an electric field creates a motional $v\\times E$ magnetic field, which when combined with collisions, produces variations of the total magnetic field and results in spin relaxation of neutron and $^{3}$He samples. The spin relaxation times $T_{1}$ (longitudinal) and $T_{2}$ (transverse) of spin-polarized UCN and $^{3}$He atoms are important considerations in a new search for the neutron Electric Dipole Moment at the SNS \\emph{nEDM} experiment. We use a Monte Carlo approach to simulate the relaxation of spins due to the motional $v\\times E$ field for UCN and for $^{3}$He atoms at temperatures below $600,\\mathrm{mK}$. We find the relaxation times for the neutron due to the $v\\times E$ effect to be long compared to the neutron lifetime, while the $^{3}$He relaxation times may be important for the \\emph{nEDM} experiment.
Black Hole Spin in AGN and GBHCs
Christopher S. Reynolds; Laura W. Brenneman; David Garofalo
2004-10-05
We discuss constraints on black hole spin and spin-related astrophysics as derived from X-ray spectroscopy. After a brief discussion about the robustness with which X-ray spectroscopy can be used to probe strong gravity, we summarize how these techniques can constrain black hole spin. In particular, we highlight XMM-Newton studies of the Seyfert galaxy MCG-6-30-15 and the stellar-mass black hole GX339-4. The broad X-ray iron line profile, together with reasonable and general astrophysical assumptions, allow a non-rotating black hole to be rejected in both of these sources. If we make the stronger assertion of no emission from within the innermost stable circular orbit, the MCG-6-30-15 data constrain the dimensionless spin parameter to be a>0.93. Furthermore, these XMM-Newton data are already providing evidence for exotic spin-related astrophysics in the central regions of this object. We conclude with a discussion of the impact that Constellation-X will have on the study of strong gravity and black hole spin.
Rogers, John A.
Technology Review: Angle Speeds Plastic Transistor http > COMPUTERS AND ELECTRONICS > SEMICONDUCTORS Angle Speeds Plastic Transistor Technology Research News April 13. #12;Technology Review: Angle Speeds Plastic Transistor http
Branislav K. Nikolic; Satofumi Souma
2005-03-17
By viewing current in the detecting lead of a spintronic device as being an ensemble of flowing spins corresponding to a mixed quantum state, where each spin itself is generally described by an improper mixture generated during the transport where it couples to other degrees of freedom due to spin-orbit (SO) interactions or inhomogeneous magnetic fields, we introduce the spin density operator associated with such current expressed in terms of the spin-resolved Landauer transmission matrix of the device. This formalism, which provides complete description of coupled spin-charge quantum transport in open finite-size systems attached to external probes, is employed to understand how initially injected pure spin states, comprising fully spin-polarized current, evolve into the mixed ones corresponding to partially polarized current. We analyze particular routes that diminish spin coherence (signified by decay of the off-diagonal elements of the current spin density matrix) in two-dimensional electron gas-based devices due to the interplay of the Rashba and/or Dresselhaus SO coupling and: (i) scattering at the boundaries or lead-wire interface in ballistic semiconductor nanowires; or (ii) spin-independent scattering off static impurities in both weakly and strongly localized disordered nanowires. The physical interpretation of spin decoherence in the course of multichannel quantum transport in terms of the entanglement of spin to an effectively zero-temperature ``environment'' composed of more than one open orbital conducting channels offers insight into some of the key challenges for spintronics: controlling decoherence of transported spins and emergence of partially coherent spin states in all-electrical spin manipulation schemes based on the SO interactions in realistic semiconductor structures.
Analysis of higher spin black holes with spin-4 chemical potential
Matteo Beccaria; Guido Macorini
2014-01-13
We consider the $AdS_{3}/CFT_{2}$ duality between certain coset WZW theories at large central charge and Vasiliev 3D higher spin gravity with a single complex field. On the gravity side, we discuss a higher spin black hole solution with chemical potential coupled to the spin-4 charge. We compute the perturbative expansion of the higher spin charges and of the partition function at high order in the chemical potential. The result is obtained with its exact dependence on the parameter $\\lambda$ characterising the symmetry algebra $\\mbox{hs}[\\lambda]$. The cases of $\\lambda=0,1$ are successfully compared with a CFT calculation. The special point $\\lambda=\\infty$, the Bergshoeff-Blencowe-Stelle limit, is also solved in terms of the exact generating function for the partition function. The thermodynamics of both the spin-4 and the usual spin-3 black holes is studied in order to discuss the $\\lambda$ dependence of the BTZ critical temperature $T_{\\rm BTZ}(\\lambda)$. In the spin-3 case, it is shown that $T_{\\rm BTZ}(\\lambda)$ converges for large $\\lambda$ to the critical point of the $\\lambda=\\infty$ known partition function previously found by the authors. In the spin-4 black hole, the picture is qualitatively similar and $T_{\\rm BTZ}(\\infty)$ is accurately determined by various numerical methods.
Tománek, David
also been suggested as a good candidate for spin-based quantum computing and spintronics [3-polarized [11], making zigzag GNRs attractive for spintronics [12]. In addition, edge states are expected be used as spin injectors or detectors in graphene spintronics. We start with a description
Internal Spin Control, Squeezing and Decoherence in Ensembles of Alkali Atomic Spins
Leigh M. Norris
2014-10-01
This dissertation studies spin squeezing, entanglement and decoherence in large ensembles of cold, trapped alkali atoms with hyperfine spin f interacting with optical fields. Restricting the state of each atom to a qutrit embedded in the 2f+1 dimensional hyperfine spin enables us to efficiently model the coherent and dissipative dynamics of the ensemble. This formalism also allows us to explore the effects of local control on the internal hyperfine spins of the atoms. State preparation using such control increases the entangling power of the atom-light interface for f>1/2. Subsequent control of the internal spins converts entanglement into metrologically relevant spin squeezing. In the case of squeezing by quantum nondemolition measurement, we employ a numerical search to find state preparations that maximize spin squeezing in the presence of decoherence. Dissipative dynamics on our system include optical pumping due to spontaneous emission. While most works ignore optical pumping or treat it phenomenologically, we employ a master equation derived from first principles. This work is extended to the case of an atomic ensemble interacting with a non-homogeneous paraxial probe. The geometries of the ensemble and the probe are optimized to maximize both spatial mode matching and spin squeezing.
New Mixing Angles in the Left-Right Symmetric Model
Kokado, Akira
2015-01-01
The left-right symmetric model is characterized by three mixing angles $\\theta _{12}, \\theta_{23}, \\theta_{13}$ between three gauge fields $B_\\mu , W^3_{L\\mu }, W^3_{R\\mu }$, which produce mass eigenstates $A_{\\mu }, Z_{\\mu }, Z'_{\\mu }$. The mass matrix can be diagonal if $\\tan{\\theta _{23}}=-\\sin{\\theta _{12}}\\sin{\\theta_{13}}/\\cos{\\theta_{12}} + O(\\delta )$ , where $\\delta $ is an infinitesimally small parameter associated with the spontaneously broken left-right symmetry. Taking the limit $\\delta \\to 0$, then introducing new variables $s'=\\sin{\\theta _{12}}\\cos{\\theta _{13}}$ and $c'=\\cos{\\theta _{12}}/\\cos{\\theta _{23}}$ with $s'^2 + c'^2 =1$, we show that all gauge boson masses can be expressed in terms of $s', c'$, namely, $M_W =$ 37.3 $/s'$ [Gev/$c^2$] and $M_Z/M_W=1/c'$. Coupling strengths between the proton and the $Z$ boson as well as those of neutrinos and $Z$ can be shown to be expressed by $s' , c'$. All results are completely the same as those of the Weinberg-Salam theory with $SU(2)_{L}\\times ...
Measurements of the CKM Angle Alpha at BaBar
Stracka, Simone; /Milan U. /INFN, Milan
2012-04-04
The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.
Angle stations in or for endless conveyor belts
Steel, Alan (Glasgow, GB6)
1987-04-07
In an angle station for an endless conveyor belt, there are presented to each incoming run of the belt stationary curved guide members (18, 19) of the shape of a major segment of a right-circular cylinder and having in the part-cylindrical portion (16 or 17) thereof rectangular openings (15) arranged in parallel and helical paths and through which project small freely-rotatable rollers (14), the continuously-changing segments of the curved surfaces of which projecting through said openings (15) are in attitude to change the direction of travel of the belt (13) through 90.degree. during passage of the belt about the part-cylindrical portion (16 or 17) of the guide member (18 or 19). The rectangular openings (15) are arranged with their longer edges lengthwise of the diagonals representing the mean of the helix but with those of a plurality of the rows nearest to each end of the part-cylindrical portion (16 or 17) slightly out of axial symmetry with said diagonals, being slightly inclined in a direction about the intersections (40) of the diagonals of the main portion of the openings, to provide a "toe-in" attitude in relation to the line of run of the endless conveyor belt.
Small angle elastic scattering of protons off of spinless nuclei
Ling, A.G.
1988-07-01
Elastic differential cross sections and analyzing powers for 800 MeV protons incident on /sup 12/C, /sup 40/Ca, and /sup 208/Pb in the momentum transfer range 20 MeV/c < q < 130 MeV/c have been measured. The data was taken with the High Resolution Spectrometer (HRS) at the Los Alamos Meson Physics Facility. Special delay-line drift chambers with dead regions for the beam to pass through them were used to obtain the data. Through the interference of the Coulomb and nuclear contributions to the differential cross section in the small angle region, the ratio of the real to imaginary part of the forward nuclear amplitude ..cap alpha../sub n/(0) = Ref/sub n/(0)/Imf/sub n/(0) is extracted. The importance of knowing this quantity at lower energies in order to study the differences between relativistic and non-relativistic scattering theories is discussed. 130 refs., 60 figs., 12 tabs.
Electric field induced spin wave generation for beyond CMOS magnonic logic devices
Nath, Jayshankar
2012-01-01
field induced spin wave generation for beyond CMOS magnonicfield induced spin wave generation for beyond CMOS magnonica novel method of spin wave generation using the strain
Spin-orbit interaction in multiple quantum wells
Hao, Ya-Fei
2015-01-07
In this paper, we investigate how the structure of multiple quantum wells affects spin-orbit interactions. To increase the interface-related Rashba spin splitting and the strength of the interface-related Rashba spin-orbit interaction, we designed three kinds of multiple quantum wells. We demonstrate that the structure of the multiple quantum wells strongly affected the interface-related Rashba spin-orbit interaction, increasing the interface-related Rashba spin splitting to up to 26% larger in multiple quantum wells than in a stepped quantum well. We also show that the cubic Dresselhaus spin-orbit interaction similarly influenced the spin relaxation time of multiple quantum wells and that of a stepped quantum well. The increase in the interface-related Rashba spin splitting originates from the relationship between interface-related Rashba spin splitting and electron probability density. Our results suggest that multiple quantum wells can be good candidates for spintronic devices.
Nikolic, Branislav K.
Decoherence of transported spin in multichannel spin-orbit-coupled spintronic devices: Scattering current in the detecting lead of a spintronic device as being an ensemble of flowing spins corresponding of open orbital conducting channels offers insight into some of the key challenges for spintronics
Charge noise, spin-orbit coupling, and dephasing of single-spin qubits
Bermeister, Adam; Keith, Daniel; Culcer, Dimitrie
2014-11-10
Quantum dot quantum computing architectures rely on systems in which inversion symmetry is broken, and spin-orbit coupling is present, causing even single-spin qubits to be susceptible to charge noise. We derive an effective Hamiltonian for the combined action of noise and spin-orbit coupling on a single-spin qubit, identify the mechanisms behind dephasing, and estimate the free induction decay dephasing times T{sub 2}{sup *} for common materials such as Si and GaAs. Dephasing is driven by noise matrix elements that cause relative fluctuations between orbital levels, which are dominated by screened whole charge defects and unscreened dipole defects in the substrate. Dephasing times T{sub 2}{sup *} differ markedly between materials and can be enhanced by increasing gate fields, choosing materials with weak spin-orbit, making dots narrower, or using accumulation dots.
Highly selective detection of individual nuclear spins with rotary echo on an electron spin probe
Mkhitaryan, V. V.; Jelezko, F.; Dobrovitski, V. V.
2015-10-26
We consider an electronic spin, such as a nitrogen-vacancy center in diamond, weakly coupled to a large number of nuclear spins, and subjected to the Rabi driving with a periodically alternating phase. We show that by switching the driving phase synchronously with the precession of a given nuclear spin, the interaction to this spin is selectively enhanced, while the rest of the bath remains decoupled. The enhancement is of resonant character. The key feature of the suggested scheme is that the width of the resonance is adjustable, and can be greatly decreased by increasing the driving strength. Thus, the resonance can be significantly narrowed, by a factor of 10–100 in comparison with the existing detection methods. Significant improvement in selectivity is explained analytically and confirmed by direct numerical many-spin simulations. As a result, the method can be applied to a wide range of solid-state systems.
Highly selective detection of individual nuclear spins with rotary echo on an electron spin probe
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mkhitaryan, V. V.; Jelezko, F.; Dobrovitski, V. V.
2015-10-26
We consider an electronic spin, such as a nitrogen-vacancy center in diamond, weakly coupled to a large number of nuclear spins, and subjected to the Rabi driving with a periodically alternating phase. We show that by switching the driving phase synchronously with the precession of a given nuclear spin, the interaction to this spin is selectively enhanced, while the rest of the bath remains decoupled. The enhancement is of resonant character. The key feature of the suggested scheme is that the width of the resonance is adjustable, and can be greatly decreased by increasing the driving strength. Thus, the resonancemore »can be significantly narrowed, by a factor of 10–100 in comparison with the existing detection methods. Significant improvement in selectivity is explained analytically and confirmed by direct numerical many-spin simulations. As a result, the method can be applied to a wide range of solid-state systems.« less
Current-based detection of nonlocal spin transport in graphene for spin-based logic applications
Wen, Hua; Amamou, Walid; Zhu, Tiancong; Luo, Yunqiu; Kawakami, Roland K.
2014-05-07
Graphene has been proposed for novel spintronic devices due to its robust and efficient spin transport properties at room temperature. Some of the most promising proposals require current-based readout for integration purposes, but the current-based detection of spin accumulation has not yet been developed. In this work, we demonstrate current-based detection of spin transport in graphene using a modified nonlocal geometry. By adding a variable shunt resistor in parallel to the nonlocal voltmeter, we are able to systematically cross over from the conventional voltage-based detection to current-based detection. As the shunt resistor is reduced, the output current from the spin accumulation increases as the shunt resistance drops below a characteristic value R*. We analyze this behavior using a one-dimensional drift-diffusion model, which accounts well for the observed behavior. These results provide the experimental and theoretical foundation for current-based detection of nonlocal spin transport.
Quantum Otto engine with a spin $1/2$ coupled to an arbitrary spin
Ferdi Altintas; Özgür E. Müstecapl?o?lu
2015-06-30
We investigate a quantum heat engine with a working substance of two particles, one with a spin $1/2$ and the other with an arbitrary spin (spin $s$), coupled by Heisenberg exchange interaction, and subject to an external magnetic field. The engine operates in a quantum Otto cycle. Work harvested in the cycle and its efficiency are calculated using quantum thermodynamical definitions. It is found that the engine has higher efficiencies at higher spins and can harvest work at higher exchange interaction strengths. The role of exchange coupling and spin $s$ on the work output and the thermal efficiency is studied in detail. In addition, the engine operation is analyzed from the perspective of local work and efficiency. The local work definition is generalized for the global changes and the conditions when the global work can be equal or more than the sum of the local works are determined.
Method and apparatus for controlling pitch and flap angles of a wind turbine
Deering, Kenneth J. (Seattle, WA); Wohlwend, Keith P. (Issaquah, WA)
2009-05-12
A wind turbine with improved response to wind conditions is provided. Blade flap angle motion is accompanied by a change in pitch angle by an amount defining a pitch/flap coupling ratio. The coupling ratio is non-constant as a function of a flap angle and is preferably a substantially continuous, non-linear function of flap angle. The non-constant coupling ratio can be provided by mechanical systems such as a series of linkages or by configuring electronic or other control systems and/or angle sensors. A link with a movable proximal end advantageously is part of the mechanical system. The system can provide relatively large coupling ratios and relatively large rates of coupling ratio changes especially for near-feather pitches and low flap angles.
Optimum angle for side injection of electrons into linear plasma wakefields
Lotov, Konstantin V
2012-01-01
A unified model of electron penetration into linear plasma wakefields is formulated and studied. The optimum angle for side injection of electrons is found. At smaller angles, all electrons are reflected radially. At larger angles, electrons enter the wakefield with superfluous transverse momentum that is unfavorable for trapping. Separation of incident electrons into penetrated and reflected fractions occur in the outer region of the wakefield at some "reflection" radius that depends on the electron energy.
A study of contact angles in porous solids using heat pipes
Collins, Richard Clark
1971-01-01
A STUDY OF CONTACT ANGLES IN FOROUS SOLIDS USING HEAT PIPES A Thesis by RICHARD CLARK COLLINS Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1971... Major Subject: Mechanical Engineering A STUDY OF CONTACT ANGLES IN POROUS SOLIDS USING HEAT PIPES A Thesis RICHARD CLARK COLLINS Approved as to style and content by; (~(, (Head of Department) (Member) May 1971 ABSTRACT A Study of Contact Angles...
New Results on Nucleon Spin Structure
Jian-Ping Chen
2005-09-10
Recent precision spin structure data from Jefferson Lab have significantly advanced our knowledge of nucleon structure in the valence quark (high-x) region and improved our understanding of higher-twist effects, spin sum rules and quark-hadron duality. First, results of a precision measurement of the neutron spin asymmetry, A{sub 1}{sup n}, in the high-x region are discussed. The new data shows clearly, for the first time, that A{sub 1}{sup n} becomes positive at high x. They provide crucial input for the global fits to world data to extract polarized parton distribution functions. Preliminary results on A{sub 1}{sup p} and A{sub 1}{sup d} in the high-x region have also become available. The up and down quark spin distributions in the nucleon were extracted. The results for {Delta}d/d disagree with the leading-order pQCD prediction assuming hadron helicity conservation. Then, results of a precision measurement of the g{sub 2}{sup n} structure function to study higher-twist effects are presented. The data show a clear deviation from the lead-twist contribution, indicating a significant higher-twist (twist-3 or higher) effect. The second moment of the spin structure functions and the twist-3 matrix element d{sub 2}{sup n} results were extracted at a high Q{sup 2} of 5 GeV{sup 2} from the measured A{sub 2}{sup n} in the high-x region in combination with existing world data and compared with a Lattice QCD calculation. Results for d{sub 2}{sup n} at low-to-intermediate Q{sup 2} from 0.1 to 0.9 GeV{sup 2} were also extracted from the JLab data. In the same Q{sup 2} range, the Q{sup 2} dependence of the moments of the nucleon spin structure functions was measured, providing a unique bridge linking the quark-gluon picture of the nucleon and the coherent hadronic picture. Sum rules and generalized forward spin polarizabilities were extracted and compared with Chiral Perturbation Theory calculations and phenomenological models. Finally, preliminary results on the resonance spin structure functions in the Q{sup 2} range from 1 to 4 GeV{sup 2} were presented, which, in combination with DIS data, will enable a detailed study of the quark-hadron duality in spin structure functions.
Konstantine Zelator
2012-03-12
In one of the three 2010/2011 issues of the journal 'MathematicalSpectrum', this author gave a three-parameter description of the entire set of integral triangles(i.e. triangles with integer side lengths)and with a 120 degree angle.This entire set expressed as a union of four families, see reference[5]. In this work we describe, in terms of three parameters again, the set of all integral with a 120 degree angle, and whose bisectors of their 120 degree angles; is also of integral length. To do so, we use the well known historic theorem of Ptolemy for cyclic quadrilaterals, in conjunction with the general positive integer solution of the equation, 1/z=1/x +1/y; and of course in combination with the parametric description of the set of integral triangles with a 120 degree angle mentioned above,The final results of this paper are found in section8.
Tilt and Rotation Angles of a Transmembrane Model Peptide as Studied by Fluorescence Spectroscopy
Gelb, Michael
concentrations of cholesterol, small changes in tilt angle were observed as response to hydro- phobic mismatch). Similar results have been re- ported for other small natural membrane peptides
Acoustic And Elastic Reverse-Time Migration: Novel Angle-Domain Imaging Conditions And Applications
Yan, Rui
2013-01-01
S. Wu, 1996, Prestack depth migration with acoustic screenN. D. , 1983, Iterative depth migration by backward time1355. ——–, 2003, Prestack depth migration in angle-domain
Ray tracing flux calculation for the small and wide angle x-ray...
Office of Scientific and Technical Information (OSTI)
station at the SESAME synchrotron radiation facility The calculation for the optics of the synchrotron radiation small and wide angle x-ray scattering beamline, currently...
Spin Dependence of Dark Matter Scattering
Vernon Barger; Wai-Yee Keung; Gabe Shaughnessy
2008-06-11
New experiments designed to discover a weakly interacting dark matter (DM) particle via spin dependent scattering can distinguish models of electroweak symmetry breaking. The plane of spin dependent versus spin independent DM scattering cross sections is a powerful model diagnostic. We detail representative predictions of mSUGRA, singlet extended SM and MSSM, a new Dirac neutrino, Littlest Higgs with T-parity (LHT) and Minimal Universal Extra Dimensions (mUED) models. Of these models, the nMSSM has the largest spin dependent (SD) cross section. It has a very light neutralino which would give lower energy nuclear recoils. The Focus Point region of mSUGRA, mUED and the right handed neutrino also predict a very large SD cross section and predict a large signal of high energy neutrinos in the IceCube experiment from annihilations of dark matter in the Sun. We also describe a model independent treatment of the scattering of DM particles of different intrinsic spins.
Nucleon Spin Structure: Longitudinal and Transverse
Jian-Ping Chen
2011-02-01
Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.
Electron spin magnetism of zigzag graphene nanoribbon edge states
Xu, Kun Ye, Peide D.
2014-04-21
The electron spin states of zigzag graphene nanoribbon (ZGNR) edge play a pivotal role in the applications of graphene nanoribbons. However, the exact arrangements of the electron spins remain unclear to date. In this report, the electronic spin states of the ZGNR edge have been elucidated through a combination of quantum chemical investigation and previous electron spin resonance experiment observations. An alternating ? and ? spin configuration of the unpaired electrons along the ZGNR edge is established in ambient condition without any external magnetic field, and the origin of the spin magnetism of the ZGNR edge is revealed. It paves a pathway for the understanding and design of graphene based electronic and spintronic devices.
Tunable Polarization of Spin Polarized Current by Magnetic Field
Joo, S.; Kim, K.; Lee, J.; Kim, T.; Rhie, K.; Hong, J.; Shin, K-H.
2010-10-10
The spin polarization of a high g-factor bulk semiconductor is theoretically investigated in the presence of a magnetic field parallel to a driving electric field. Calculations have been carried out using the energy-dependent relaxation time approximation in association with spin-flip scattering. As the magnitude of the magnetic field increases, the spin-polarized current alternates between the spin-up and spin-down states for the low spin-scattering system. This implies that the current polarization can be tuned by controlling the magnetic field strength, suggesting possible applications to spintronic devices. An experimental method for investigating alternative current polarization is also considered.
Spin-dependent terahertz oscillator based on hybrid graphene superlattices
Díaz, E.; Miralles, K.; Domínguez-Adame, F. [GISC, Departamento Física de Materiales, Universidad Complutense, E-28040 Madrid (Spain); Gaul, C., E-mail: cgaul@pks.mpg.de [Max Planck Institute for the Physics of Complex Systems, 01187 Dresden (Germany)
2014-09-08
We theoretically study the occurrence of Bloch oscillations in biased hybrid graphene systems with spin-dependent superlattices. The spin-dependent potential is realized by a set of ferromagnetic insulator strips deposited on top of a gapped graphene nanoribbon, which induce a proximity exchange splitting of the electronic states in the graphene monolayer. We numerically solve the Dirac equation and study Bloch oscillations in the lowest conduction band of the spin-dependent superlattice. While the Bloch frequency is the same for both spins, we find the Bloch amplitude to be spin dependent. This difference results in a spin-polarized ac electric current in the THz range.
Higher Spin Currents in Wolf Space: Part III
Changhyun Ahn
2015-04-01
The large N=4 linear superconformal algebra (generated by four spin-1/2 currents, seven spin-1 currents, four spin-3/2 currents and one spin-2 current) found by Sevrin, Troost and Van Proeyen (and other groups) was realized in the N=4 superconformal coset SU(5)/SU(3) theory previously. The lowest 16 higher spin currents of spins (1, 3/2, 3/2, 2), (3/2, 2, 2, 5/2), (3/2, 2, 2, 5/2) and (2, 5/2, 5/2, 3) are obtained by starting with the operator product expansions (OPEs) between the four spin-3/2 currents from the above large N=4 linear superconformal algebra and the lowest higher spin-1 current which is the same as the one in the Wolf space coset SU(5)/[SU(3) x SU(2) x U(1)] theory. These OPEs determine the four higher spin-3/2 currents and the next six higher spin-2 currents are obtained from the OPEs between the above four spin-3/2 currents associated with the N=4 supersymmetry and these four higher spin-3/2 currents. The four higher spin-5/2 currents can be determined by calculating the OPEs between the above four spin-3/2 currents and the higher spin-2 currents. Similarly, the higher spin-3 current is obtained from the OPEs between the four spin-3/2 currents and the higher spin-5/2 currents. The explicit relations between the above 16 higher spin currents and the corresponding 16 higher spin currents which were found in the extension of large N=4 nonlinear superconformal algebra previously are given. By examining the OPEs between the 16 currents from the large N=4 linear superconformal algebra and the 16 higher spin currents, the match with the findings of Beccaria, Candu and Gaberdiel is also given. The next 16 higher spin currents of spins (2, 5/2, 5/2, 3), (5/2, 3, 3, 7/2), (5/2, 3, 3, 7/2) and (3, 7/2, 7/2, 4) occur from the OPEs between the above lowest 16 higher spin currents.
Sinitsyn, NA; Hankiewicz, EM; Teizer, Winfried; Sinova, Jairo.
2004-01-01
-split subbands being occupied.8 Motivated by re- cent experiments12,13 which have demonstrated the ability to tune the magnitude of the Rashba and Dresselhaus spin-orbit coupling strength directly and by the fact that when both coupling strengths are equal... Hall effect accounts rather convincingly for experimental observations.36 Besides the several approaches already proposed to mea- sure the spin-Hall effect,7,8,12,37 the tunability of both the Rashba and Dresselhaus coupling parameters12,13...
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Albert Mendoza; Yan Shi; Connor Flynn
Shortwave Array Spectroradiometer-Hemispheric, VISible channel, low-sun angles [a0 data is uncalibrated
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Albert Mendoza; Yan Shi; Connor Flynn
Shortwave Array Spectroradiometer-Hemispheric, VISible channel, high-sun angles [a0 data is uncalibrated
Albert Mendoza; Yan Shi; Connor Flynn
2011-03-22
Shortwave Array Spectroradiometer-Hemispheric, VISible channel, high-sun angles [a0 data is uncalibrated
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Albert Mendoza; Yan Shi; Connor Flynn
1990-01-01
Shortwave Array Spectroradiometer-Hemispheric, VISible channel, low-sun angles [a0 data is uncalibrated
Lin, X; Sun, T; Liu, T; Zhang, G; Yin, Y
2014-06-01
Purpose: To evaluate the dosimetric characteristics of intensity-modulated radiotherapy (IMRT) treatment plan with beam angle optimization. Methods: Ten post-operation patients with cervical cancer were included in this analysis. Two IMRT plans using seven beams were designed in each patient. A standard coplanar equi-space beam angles were used in the first plan (plan 1), whereas the selection of beam angle was optimized by beam angle optimization algorithm in Varian Eclipse treatment planning system for the same number of beams in the second plan (plan 2). Two plans were designed for each patient with the same dose-volume constraints and prescription dose. All plans were normalized to the mean dose to PTV. The dose distribution in the target, the dose to the organs at risk and total MU were compared. Results: For conformity and homogeneity in PTV, no statistically differences were observed in the two plans. For the mean dose in bladder, plan 2 were significantly lower than plan 1(p<0.05). No statistically significant differences were observed between two plans for the mean doses in rectum, left and right femur heads. Compared with plan1, the average monitor units reduced 16% in plan 2. Conclusion: The IMRT plan based on beam angle optimization for cervical cancer could reduce the dose delivered to bladder and also reduce MU. Therefore there were some dosimetric advantages in the IMRT plan with beam angle optimization for cervical cancer.
High spin states in {sup 139}Pm
Dhal, A.; Sinha, R. K.; Chaturvedi, L.; Agarwal, P.; Kumar, S.; Jain, A. K.; Kumar, R.; Govil, I. M.; Mukhopadhyay, S.; Chakraborty, A.; Krishichayan; Ray, S.; Ghugre, S. S.; Sinha, A. K.; Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K.; Pancholi, S. C.; Gupta, J. B. [Department of Physics, Banaras Hindu University, Varanasi-221 005 (India); Department of Physics, IIT Roorkee, Roorkee-247 667 (India); Department of Physics, Panjab University, Chandigarh-160 014 (India); UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata-700 098 (India); Inter University Accelerator Centre, New Delhi-110 067 (India); Ramjas College, Delhi University, Delhi-110 007 (India)
2009-07-15
The odd mass nucleus {sup 139}Pm has been studied to high spins through the {sup 116}Cd({sup 27}Al,4n){sup 139}Pm reaction at an incident beam energy of 120 MeV. The de-exciting {gamma}-rays were detected using an array of 12 Compton suppressed Ge detectors. A total of 46 new levels have been proposed in the present work as a result of the observation of 60 new {gamma}-rays. Four new bands including a {delta}J=1 sequence have been identified and all the earlier reported bands, other than the yrast band, have been extended to higher spins and excitation energy. The spin assignments for most of the newly reported levels have been made using the observed coincidence angular anisotropy. Tilted axis cranking calculations support the interpretation of two of the observed magnetic dipole sequences as examples of magnetic rotational bands.
Dissipative Quantum Metrology with Spin Cat States
Jiahao Huang; Xizhou Qin; Honghua Zhong; Yongguan Ke; Chaohong Lee
2014-10-28
The maximally entangled states are excellent candidates for achieving Heisenberg-limited measurements in ideal quantum metrology, however, they are fragile against dissipation such as particle losses and their achievable precisions may become even worse than the standard quantum limit (SQL). Here we present a robust high-precision measurement scheme via spin cat states (a kind of non-Gaussian entangled states in superposition of two spin coherent states) in the presence of particle losses. The input spin cat states are of excellent robustness against particle losses and their achievable precisions may still beat the SQL. For realistic measurements based upon our scheme, comparing with the population measurement, the parity measurement is more suitable for yielding higher precisions. In phase measurement with realistic dissipative systems of bosons, our scheme provides a robust and realizable way to achieve high-precision measurements beyond the SQL.
Spin and Resonant States in QCD
Kirchbach, M
2003-01-01
I make the case that the nucleon excitations do not exist as isolated higher spin states but are fully absorbed by (K/2,K/2)x [(1/2,0)+(0,1/2)] multiplets taking their origin from the rotational and vibrational excitations of an underlying quark--diquark string. The Delta(1232) spectrum presents itself as the exact replica (up to Delta (1600)) of the nucleon spectrum with the K- clusters being shifted upward by about 200 MeV. QCD inspired arguments support legitimacy of the quark-diquark string. The above K multiplets can be mapped (up to form-factors) onto Lorentz group representation spaces of the type \\psi_{\\mu_1...\\mu_K}, thus guaranteeing covariant description of resonant states. The quantum \\psi_{\\mu_1...\\mu_K} states are of multiple spins at rest, and of undetermined spins elsewhere.
Quantum Optics of Chiral Spin Networks
Hannes Pichler; Tomás Ramos; Andrew J. Daley; Peter Zoller
2015-04-15
We study the driven-dissipative dynamics of a network of spin-1/2 systems coupled to one or more chiral 1D bosonic waveguides within the framework of a Markovian master equation. We determine how the interplay between a coherent drive and collective decay processes can lead to the formation of pure multipartite entangled steady states. The key ingredient for the emergence of these many-body dark states is an asymmetric coupling of the spins to left and right propagating guided modes. Such systems are motived by experimental possibilities with internal states of atoms coupled to optical fibers, or motional states of trapped atoms coupled to a spin-orbit coupled Bose-Einstein condensate. We discuss the characterization of the emerging multipartite entanglement in this system in terms of the Fisher information.
Decoherence of spin-deformed bosonic model
Dehdashti, Sh.; Mahdifar, A.; Bagheri Harouni, M.; Roknizadeh, R.
2013-07-15
The decoherence rate and some parameters affecting it are investigated for the generalized spin-boson model. We consider the spin-bosonic model when the bosonic environment is modeled by the deformed harmonic oscillators. We show that the state of the environment approaches a non-linear coherent state. Then, we obtain the decoherence rate of a two-level system which is in contact with a deformed bosonic environment which is either in thermal equilibrium or in the ground state. By using some recent realization of f-deformed oscillators, we show that some physical parameters strongly affect the decoherence rate of a two-level system. -- Highlights: •Decoherence of the generalized spin-boson model is considered. •In this model the environment consists of f-oscillators. •Via the interaction, the state of the environment approaches non-linear coherent states. •Effective parameters on decoherence are considered.
Higher Spin Currents in Wolf Space: Part III
Ahn, Changhyun
2015-01-01
The large N=4 linear superconformal algebra (generated by four spin-1/2 currents, seven spin-1 currents, four spin-3/2 currents and one spin-2 current) found by Sevrin, Troost and Van Proeyen (and other groups) was realized in the N=4 superconformal coset SU(5)/SU(3) theory previously. The lowest 16 higher spin currents of spins (1, 3/2, 3/2, 2), (3/2, 2, 2, 5/2), (3/2, 2, 2, 5/2) and (2, 5/2, 5/2, 3) are obtained by starting with the operator product expansions (OPEs) between the four spin-3/2 currents from the above large N=4 linear superconformal algebra and the lowest higher spin-1 current which is the same as the one in the Wolf space coset SU(5)/[SU(3) x SU(2) x U(1)] theory. These OPEs determine the four higher spin-3/2 currents and the next six higher spin-2 currents are obtained from the OPEs between the above four spin-3/2 currents associated with the N=4 supersymmetry and these four higher spin-3/2 currents. The four higher spin-5/2 currents can be determined by calculating the OPEs between the abo...
Eslami, L., E-mail: Leslami@iust.ac.ir; Faizabadi, E. [School of Physics, Iran University of Science and Technology, Tehran 16846 (Iran, Islamic Republic of)
2014-05-28
The effect of magnetic contacts on spin-dependent electron transport and spin-accumulation in a quantum ring, which is threaded by a magnetic flux, is studied. The quantum ring is made up of four quantum dots, where two of them possess magnetic structure and other ones are subjected to the Rashba spin-orbit coupling. The magnetic quantum dots, referred to as magnetic quantum contacts, are connected to two external leads. Two different configurations of magnetic moments of the quantum contacts are considered; the parallel and the anti-parallel ones. When the magnetic moments are parallel, the degeneracy between the transmission coefficients of spin-up and spin-down electrons is lifted and the system can be adjusted to operate as a spin-filter. In addition, the accumulation of spin-up and spin-down electrons in non-magnetic quantum dots are different in the case of parallel magnetic moments. When the intra-dot Coulomb interaction is taken into account, we find that the electron interactions participate in separation between the accumulations of electrons with different spin directions in non-magnetic quantum dots. Furthermore, the spin-accumulation in non-magnetic quantum dots can be tuned in the both parallel and anti-parallel magnetic moments by adjusting the Rashba spin-orbit strength and the magnetic flux. Thus, the quantum ring with magnetic quantum contacts could be utilized to create tunable local magnetic moments which can be used in designing optimized nanodevices.
Electron Spin Resonance Spectroscopy via Relaxation of Solid-State Spin Probes at the Nanoscale
L. T. Hall; P. Kehayias; D. A. Simpson; A. Jarmola; A. Stacey; D. Budker; L. C. L. Hollenberg
2015-03-03
Electron Spin Resonance (ESR) describes a suite of techniques for characterising electronic systems, with applications in physics, materials science, chemistry, and biology. However, the requirement for large electron spin ensembles in conventional ESR techniques limits their spatial resolution. Here we present a method for measuring the ESR spectrum of nanoscale electronic environments by measuring the relaxation time ($T_1$) of an optically addressed single-spin probe as it is systematically tuned into resonance with the target electronic system. As a proof of concept we extract the spectral distribution for the P1 electronic spin bath in diamond using an ensemble of nitrogen-vacancy centres, and demonstrate excellent agreement with theoretical expectations. As the response of each NV spin in this experiment is dominated by a single P1 spin at a mean distance of 2.7\\,nm, the extension of this all-optical technique to the single NV case will enable nanoscale ESR spectroscopy of atomic and molecular spin systems.
Neutron single target spin asymmetries in SIDIS
Evaristo Cisbani
2010-04-01
The experiment E06-010 in Hall A at Jefferson Lab took data between November 2008 and February 2009 to directly measure, for the first time, the pion (and kaon) single "neutron" target-spin asymmetry (SSA) in semi-inclusive DIS from a polarized 3He target. Collins, Sivers (and Pretzelosity) neutron asymmetries are going to be extracted from the measured SSA. Details of the experiment are described together with the preliminary results of the ongoing analysis. Near future Hall A experiments on transverse nucleon spin structure are shorty reviewed.
Freezing distributed entanglement in spin chains
Irene D'Amico; Brendon W. Lovett; Timothy P. Spiller
2007-08-21
We show how to freeze distributed entanglement that has been created from the natural dynamics of spin chain systems. The technique that we propose simply requires single-qubit operations and isolates the entanglement in specific qubits at the ends of branches. Such frozen entanglement provides a useful resource, for example for teleportation or distributed quantum processing. The scheme can be applied to a wide range of systems -- including actual spin systems and alternative qubit embodiments in strings of quantum dots, molecules or atoms.
Spin, Statistics, and Reflections, II. Lorentz Invariance
Bernd Kuckert; Reinhard Lorenzen
2005-12-21
The analysis of the relation between modular P$_1$CT-symmetry -- a consequence of the Unruh effect -- and Pauli's spin-statistics relation is continued. The result in the predecessor to this article is extended to the Lorentz symmetric situation. A model $\\G_L$ of the universal covering $\\widetilde{L_+^\\uparrow}\\cong SL(2,\\complex)$ of the restricted Lorentz group $L_+^\\uparrow$ is modelled as a reflection group at the classical level. Based on this picture, a representation of $\\G_L$ is constructed from pairs of modular P$_1$CT-conjugations, and this representation can easily be verified to satisfy the spin-statistics relation.
High Spins Beyond Rarita-Schwinger Framework
Kirchbach, M; Kirchbach, Mariana; Napsuciale, Mauro
2004-01-01
We explicitly construct in the Rarita-Schwinger representation space the operator of the squared Pauli-Lubanski vector and derive from it that the -15/4 m^{2} subspace (spin 3/2 in the rest frame), with well defined parity, is pinned down by the one sole equation, [\\epsilon_{\\alpha\\beta\\mu\\sigma}\\gamma_{5}\\gamma^{\\mu}p^{\\sigma} -m g_{\\alpha\\beta}]\\psi^{\\beta}=0. We argue that upon gauging the new equation leads to causal spin-3/2 propagation within an electromagnetic field, thus resolving the Velo-Zwanziger problem.
Evidence for spin selectivity of triplet pairs in superconducting spin valves
Banerjee, N.; Smiet, C. B.; Smits, R. G. J.; Ozaeta, A.; Bergeret, F. S.; Blamire, M. G.; Robinson, J. W. A.
2014-01-09
Evidence for spin-selectivity of triplet pairs in superconducting spin-valves N. Banerjee1, C. B. Smiet1, R. G. J. Smits1, A. Ozaeta2, F. S. Bergeret2, M. G. Blamire1, J. W. A. Robinson1* 1Department of Materials Science and Metallurgy, University... . Pang, B. S. H., Bell, C., Tomov, R. I., Durrell, J. H., & Blamire, M. G. Pseudo spin-valve behavior in oxide ferromagnet/superconductor/ferromagnet trilayers. Phys. Lett. A 341, 313–319 (2005). 35. Kalcheim, Y., Kirzhner, T., Koren, G. & Millo, O...
Spin-transfer switching of orthogonal spin-valve devices at cryogenic temperatures
Ye, L. Gopman, D. B.; Rehm, L.; Backes, D.; Wolf, G.; Kent, A. D.; Ohki, T.; Kirichenko, A. F.; Vernik, I. V.; Mukhanov, O. A.
2014-05-07
We present the quasi-static and dynamic switching characteristics of orthogonal spin-transfer devices incorporating an out-of-plane magnetized polarizing layer and an in-plane magnetized spin valve device at cryogenic temperatures. Switching at 12?K between parallel and anti-parallel spin-valve states is investigated for slowly varied current as well as for current pulses with durations as short as 200 ps. We demonstrate 100% switching probability with current pulses 0.6?ns in duration. We also present a switching probability diagram that summarizes device switching operation under a variety of pulse durations, amplitudes, and polarities.
Domain wall displacement by remote spin-current injection
Skirdkov, P. N.
We demonstrate numerically the ability to displace a magnetic domain wall (DW) by remote spin current injection. We consider a long and narrow magnetic nanostripe with a single DW. The spin-polarized current is injected ...
Leading Edge Spinning the Web of Cell Fate
Corces, Victor G.
Leading Edge Minireview Spinning the Web of Cell Fate Kevin Van Bortle1 and Victor G. Corces1,* 1 involved in spinning the web of cell fate. Chromatin at the Nuclear Lamina The nuclear lamina is a thin
Exploring large coherent spin systems with solid state NMR
Cho, HyungJoon, Ph. D. Massachusetts Institute of Technology
2005-01-01
Solid state Nuclear Magnetic Resonance (NMR) allows us to explore a large coherent spin system and provides an ideal test-bed for studying strongly interacting multiple-spin system in a large Hilbert space. In this thesis, ...
Nutation in the spinning SPHERES spacecraft and fluid slosh
Burke, Caley Ann
2010-01-01
Spacecraft today are often spin-stabilized during a portion their launch or mission. Though the basics of spin stabilization are well understood, there remains uncertainty in predicting the likelihood of rapid nutation ...
Local spin torque induced by electron electric dipole moment...
Office of Scientific and Technical Information (OSTI)
we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron...
ORIGINAL PAPER Effect of Pitch and Roll Static Angle on Lubricant Transfer
Siegel, Paul H.
ORIGINAL PAPER Effect of Pitch and Roll Static Angle on Lubricant Transfer Between Disk and Slider static angle on lubricant transfer between a disk and a slider in a hard disk drive. The lubricant- cant distribution on the disks was obtained using optical surface analysis. Lubricant transfer from
Light is said to be reflected when the angle at which light
Gilbes, Fernando
1 #12;2 Light is said to be reflected when the angle at which light initially strikes a surface is equal to the angle at which light bounces off the same surface. In the diagram, light strikes a surface", this is an example of reflected light. Refraction is the bending of a wave when it enters a medium where it's speed
Performing fish counts with a wide-angle camera, a promising approach reducing divers' limitations
Borges, Rita
Performing fish counts with a wide-angle camera, a promising approach reducing divers' limitations Keywords: Fish surveys Underwater video Underwater visual census Wide-angle camera Visual standardised methods for census of reef fishes have long been used in fisheries management and biolog- ical surveys
Measurement of chain tilt angle in fully hydrated bilayers of gel phase lecithins
Nagle, John F.
Measurement of chain tilt angle in fully hydrated bilayers of gel phase lecithins S. Tristram angle Otilt of the hydrocarbon chains has been determined for the fully hydrated gel phase of a series hydrocarbon chains, requiring each bilayer to scatter coherently rather than each monolayer. For DPPC, Otilt
Low angle dune response to variable flow, dune translation and crestline dynamics in Fraser
Venditti, Jeremy G.
Low angle dune response to variable flow, dune translation and crestline dynamics in Fraser Estuary Approval Name: Megan Lillian Hendershot Degree: Master of Science Title: Low angle dune response to variable flow, dune translation and crestline dynamics in Fraser Estuary, British Columbia, Canada
Wuttke, Joachim; Zamponi, Michaela [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)] [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)
2013-11-15
The resolution of neutron backscattering spectrometers deteriorates at small scattering angles where analyzers deviate from exact backscattering. By reducing the azimuth angle range of the analyzers, the resolution can be improved with little loss of peak intensity. Measurements at the spectrometer SPHERES are in excellent agreement with simulations, which proves the dominance of geometric effects.
Salt-Dependent Compaction of Di-and Trinucleosomes Studied by Small-Angle Neutron Scattering
Langowski, Jörg
Salt-Dependent Compaction of Di- and Trinucleosomes Studied by Small-Angle Neutron Scattering, Germany, and Institut Laue-Langevin Grenoble, F-38042 Grenoble, France ABSTRACT Using small-angle neutron scattering (SANS), we have measured the salt-dependent static structure factor of di- and trinucleosomes from
29 Nov 2001 A. Bacchetta -Fragmentation to probe transversity 31 Hadron pair azimuthal angle
1 29 Nov 2001 A. Bacchetta - Fragmentation to probe transversity 31 Hadron pair azimuthal angle 29 Nov 2001 A. Bacchetta - Fragmentation to probe transversity 32 Center of mass angle hadron decay plane Center of mass direction in lab frame Center of mass frame R #12;2 29 Nov 2001 A. Bacchetta
Light's Bending Angle due to Black Holes: From the Photon Sphere to Infinity
Savitri V. Iyer; Arlie O. Petters
2007-03-15
The bending angle of light is a central quantity in the theory of gravitational lensing. We develop an analytical perturbation framework for calculating the bending angle of light rays lensed by a Schwarzschild black hole. Using a perturbation parameter given in terms of the gravitational radius of the black hole and the light ray's impact parameter, we determine an invariant series for the strong-deflection bending angle that extends beyond the standard logarithmic deflection term used in the literature. In the process, we discovered an improvement to the standard logarithmic deflection term. Our perturbation framework is also used to derive as a consistency check, the recently found weak deflection bending angle series. We also reformulate the latter series in terms of a more natural invariant perturbation parameter, one that smoothly transitions between the weak and strong deflection series. We then compare our invariant strong deflection bending-angle series with the numerically integrated exact formal bending angle expression, and find less than 1% discrepancy for light rays as far out as twice the critical impact parameter. The paper concludes by showing that the strong and weak deflection bending angle series together provide an approximation that is within 1% of the exact bending angle value for light rays traversing anywhere between the photon sphere and infinity.
Directional adhesion of gecko-inspired angled microfiber arrays Jongho Lee,1
Fearing, Ron
Directional adhesion of gecko-inspired angled microfiber arrays Jongho Lee,1 Ronald S. Fearing,2. Friction experiments demonstrated that this fibrillar polymer surface exhibits directional adhesion adhesion is interpreted in the context of a nonlinear elastic bending model of an angled beam. Shearing
Stress-driven migration of simple low-angle mixed grain boundaries , M. Haataja a,
Cai, Wei
Stress-driven migration of simple low-angle mixed grain boundaries A.T. Lim a , M. Haataja a, , W investigated the stress-induced migration of a class of simple low-angle mixed grain boundaries (LAMGBs) using under an externally applied stress can occur by dislocation glide, and was observed to be coupled
Small angle neutron scattering (SANS) under non-equilibrium conditions R. C. Oberthr
Boyer, Edmond
663 Small angle neutron scattering (SANS) under non-equilibrium conditions R. C. Oberthür Institut with the times obtained from quasi- elastic neutron and light scattering, which yield information about neutrons aux petits angles (DNPA) pour l'étude des systèmes hors d'équi- libre thermodynamique est
Small angle neutron scattering on periodically deformed polymers A. R. Rennie
Boyer, Edmond
765 Small angle neutron scattering on periodically deformed polymers A. R. Rennie Institut für Phys-768 SEPTEMBRE 1984, 1. Introduction. Neutron scattering has proved a useful tool for the investigation of a wide time for a small angle neutron scattering spectrum is several minutes. Obser- vation on rapidly
High temperature furnaces for small and large angle neutron scattering of disordered materials
Boyer, Edmond
725 High temperature furnaces for small and large angle neutron scattering of disordered materials and small angle neutron scattering (SANS) experiments respectively. They are vacuum furnaces with a thin maintained in a tantalum box. In a neutron beam, the furnaces produce a very low scattering level (without
Small angle neutron scattering from single-wall carbon nanotube suspensions: evidence for isolated
Wang, Howard "Hao"
Small angle neutron scattering from single-wall carbon nanotube suspensions: evidence for isolated online: Abstract We report small angle neutron scattering (SANS) from dilute suspensions of purified University, Houghton, MI 49931, USA e NIST Center for Neutron Research, National Institute of Standards
A Longitudinal Assessment of Sleep Timing, Circadian Phase, and Phase Angle of Entrainment across of this descriptive analysis was to examine sleep timing, circadian phase, and phase angle of entrainment across of Entrainment across Human Adolescence. PLoS ONE 9(11): e112199. doi:10.1371/journal.pone.0112199 Editor: Steven
Carlson, Erica
Thermoelectric figure of merit as a function of carrier propagation angle in semiconducting;Thermoelectric figure of merit as a function of carrier propagation angle in semiconducting superlattices Shuo a fruitful approach for enhancing the figure of merit, ZT, of thermoelectric materials. Generally
Viewing spin structures with soft x-ray microscopy
Fischer, Peter
2011-01-01
R. , In: Concepts in Spintronics (ed. Maekawa, S. ) (2006)electron the concept of spintronics considers also its spin
Micro-Electron Spin Resonance for Airborne Soot Measurement
Broader source: Energy.gov [DOE]
A real-time method for airborne soot concentration measurement using a miniaturized electron spin resonance sensor is presented.
Chaotic orbits for spinning particles in Schwarzschild spacetime
Verhaaren, Chris; Hirschmann, Eric W. [Physics Department, Brigham Young University, Provo, Utah 84602 (United States)
2010-06-15
We consider the orbits of particles with spin in the Schwarzschild spacetime. Using the Papapetrou-Dixon equations of motion for spinning particles, we solve for the orbits and focus on those that exhibit chaos using both Poincare maps and Lyapunov exponents. In particular, we develop a method for comparing the Lyapunov exponents of chaotic orbits. We find chaotic orbits for smaller spin values than previously thought and find chaotic orbits with astrophysically relevant spin values.
Cross-sectional imaging of spin injection into a semiconductor
Loss, Daniel
in a cross-sectional view and to separate the effects of spin diffusion and electron drift. Spintronics--the
Shogo Tanimura
2015-04-06
The uncertainty relation between angle and orbital angular momentum had not been formulated in a similar form as the uncertainty relation between position and linear momentum because the angle variable is not represented by a quantum mechanical self-adjoint operator. Instead of the angle variable operator, we introduce the complex position operator $ \\hat{Z} = \\hat{x}+i \\hat{y} $ and interpret the order parameter $ \\mu = \\langle \\hat{Z} \\rangle / \\sqrt{ \\langle \\hat{Z}^\\dagger \\hat{Z} \\rangle} $ as a measure of certainty of the angle distribution. We prove the relation between the uncertainty of angular momentum and the angle order parameter. We prove also its generalizations and discuss experimental methods for testing these relations.
Sharma, Raghav; Dürrenfeld, P.; Iacocca, E.; Heinonen, O. G.; Åkerman, J.; Muduli, P. K.
2014-09-29
The frequency noise spectrum of a magnetic tunnel junction based spin torque oscillator is examined where multiple modes and mode-hopping events are observed. The frequency noise spectrum is found to consist of both white noise and 1/f frequency noise. We find a systematic and similar dependence of both white noise and 1/f frequency noise on bias current and the relative angle between the reference and free layers, which changes the effective damping and hence the mode-hopping behavior in this system. The frequency at which the 1/f frequency noise changes to white noise increases as the free layer is aligned away from the anti-parallel orientation w.r.t the reference layer. These results indicate that the origin of 1/f frequency noise is related to mode-hopping, which produces both white noise as well as 1/f frequency noise similar to the case of ring lasers.
NMR dynamics of quantum discord for spin-carrying gas molecules in a closed nanopore
Yurishchev, M. A., E-mail: yur@itp.ac.ru [Russian Academy of Sciences, Institute of Problems of Chemical Physics (Russian Federation)
2014-11-15
A local orthogonal transformation that transforms any centrosymmetric density matrix of a two-qubit system to the X form has been found. A piecewise-analytic-numerical formula Q = min(Q{sub ?/2}, Q{sub ?}, Q{sub 0}), where Q{sub ?/2} and Q{sub 0} are analytical expressions and the branch Q{sub 0?} can be obtained only by numerically searching for the optimal measurement angle ? ? (0, ?/2), is proposed to calculate the quantum discord Q of a general X state. The developed approaches have been applied for a quantitative description of the recently predicted flickering (periodic disappearance and reappearance) of the quantum-information pair correlation between nuclear 1/2 spins of atoms or molecules of a gas (for example, {sup 129}Xe) in a bounded volume in the presence of a strong magnetic field.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Xu, Min; Wang, Li -Min; Peng, Rui; Ge, Qing -Qin; Chen, Fei; Ye, Zi -Rong; Zhang, Yan; Chen, Su -Di; Xia, Miao; Liu, Rong -Hua; et al
2015-02-01
With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFe????Te?, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observed the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe????Te? serves as a simpler platform that containsmore »similar ingredients as the parent compounds of iron-based superconductors.« less
Coherent, Mechanical Control of a Single Electronic Spin Sungkun Hong,,
Yacoby, Amir
Coherent, Mechanical Control of a Single Electronic Spin Sungkun Hong,, Michael S. Grinolds coherent quantum control of a single spin driven by the motion of a mechanical resonator. The motion of a mechanical resonator is magnetically coupled to the electronic spin of a single nitrogen-vacancy center
Extensibility, Safety and Performance in the SPIN Operating System
Savage, Stefan
Extensibility, Safety and Performance in the SPIN Operating System Brian N. Bershad Stefan Savage the motivation, architecture and per- formance of SPIN, an extensible operating system. SPIN provides change the operating system's interface and implementation. Extensions allow an application to specialize
Luminescent spin-valve transistor Ian Appelbaum,a)
Russell, Kasey
, the spin- valve transistor SVT , modulates a hot-electron current passing perpendicularly throughLuminescent spin-valve transistor Ian Appelbaum,a) K. J. Russell, D. J. Monsma, V. Narayanamurti Received 29 July 2003; accepted 7 October 2003 A magneto-optical sensor, the luminescent spin-valve
DIFFUSION INELASTIQUE DES AIEUTRONS ET ONDES DE SPIN
Boyer, Edmond
measured in the three principal symmetry directions by neutron inelastic scattering.The spin wave of neutrons C(Eogo)scattered by a spin wave of energy Eo and wave vector qo satisfies the following diffusion inklastiquedes neutrons. On a trouvB que les relations de dispersion des ondes de spin
Spin-valve photodiode Ian Appelbaum,a)
Russell, Kasey
Spin-valve photodiode Ian Appelbaum,a) D. J. Monsma, K. J. Russell, V. Narayanamurti, and C. M; accepted 28 August 2003 An optical spin-valve effect is observed using sub-bandgap internal photoemission the ``spin-valve'' effect SVE , because the relative magnetizations of these layers, and thus the flow
Avalanche spin-valve transistor K. J. Russell,a)
Russell, Kasey
Avalanche spin-valve transistor K. J. Russell,a) Ian Appelbaum,b) Wei Yi, D. J. Monsma, F. Capasso, California 93106 (Received 11 June 2004; accepted 10 September 2004) A spin-valve transistor with a Ga allow fabrication of spin-valve transistors with high gain in a variety of materials. © 2004 American
Spin-orbit torques in ferromagnets and antiferromagnets
Gao, Huawei
2015-06-10
Spintronics is a sub-field of condensed matter physics which explores the physics of electrons involving both their charge and spin, with an emphasis on the active manipulation of the spin degree of freedom in solid state systems. In spin...
Experimental study of 199Hg spin anti-relaxation coatings
Z. Chowdhuri; M. Fertl; M. Horras; K. Kirch; J. Krempel; B. Lauss; A. Mtchedlishvili; D. Rebreyend; S. Roccia; P. Schmidt-Wellenburg; G. Zsigmond
2013-09-04
We report on a comparison of spin relaxation rates in a $^{199}$Hg magnetometer using different wall coatings. A compact mercury magnetometer was built for this purpose. Glass cells coated with fluorinated materials show longer spin coherence times than if coated with their hydrogenated homologues. The longest spin relaxation time of the mercury vapor was measured with a fluorinated paraffin wall coating.
Nonmagnetic semiconductor spin transistor K. C. Hall,a)
Flatte, Michael E.
as a spin valve, or a magnetic field sensor. © 2003 American Institute of Physics. DOI: 10 there is a natural choice of quantization axis for spin along which precessional spin re- laxation is suppressed.12 of an external electric field to a symmetric InAs two-dimensional electron gas 2DEG between the in- jector
condmat/9801215 Crossovers in the Two Dimensional Ising Spin Glass
Roma "La Sapienza", Università di
condmat/9801215 v2 26 Jan 1998 Crossovers in the Two Dimensional Ising Spin Glass of extensive computer simulations we analyze in detail the two dimen sional \\SigmaJ Ising spin glass with ferromagnetic nextnearestneighbor interactions. We found a crossover from ferromagnetic to ``spin glass'' like
Nimbalka, Manoj
We study multiple-spin coherence transfers in linear Ising spin chains with nearest-neighbor couplings. These constitute a model for efficient information transfers in future quantum computing devices and for many ...
Optical detection of spin-filter effect for electron spin polarimetry
Li, X.; Majee, S.; Lampel, G.; Lassailly, Y.; Paget, D.; Peretti, J.; Tereshchenko, O. E.
2014-08-04
We have monitored the cathodoluminescence (CL) emitted upon injection of free electrons into a hybrid structure consisting of a thin magnetic Fe layer deposited on a p-GaAs substrate, in which InGaAs quantum wells are embedded. Electrons transmitted through the unbiased metal/semiconductor junction recombine radiatively in the quantum wells. Because of the electron spin-filtering across the Fe/GaAs structure, the CL intensity, collected from the backside, is found to depend on the relative orientation between the injected electronic spin polarization and the Fe layer magnetization. The spin asymmetry of the CL intensity in such junction provides a compact optical method for measuring spin polarization of free electrons beams or of hot electrons in solid-state devices.
Valley-dependent spin polarization and long-lived electron spins in germanium
Giorgioni, Anna Vitiello, Elisa; Grilli, Emanuele; Guzzi, Mario; Pezzoli, Fabio
2014-10-13
Spin orientation and relaxation of conduction band electrons in bulk Ge are addressed by studying the steady-state circular polarization of the indirect gap photoluminescence (PL) at low temperatures. This provides a direct experimental proof of recently predicted spin-dependent selection rules for phonon-mediated optical transitions in Ge. In addition, we observe valley-dependent circularly polarized emission, and map the concomitant redistribution of electron spins within the multi-valley conduction band of Ge by gaining simultaneous access to the circular dichroism of light emitted across the direct and the indirect gap transitions. Finally, the lifetime of L-valley electrons is measured by means of decay curves of the indirect gap PL emission, yielding spin relaxation times in the order of hundreds of ns.
Spin transport in lateral spin valves and across a metal- insulator transition in V?O? /
Erekhinsky, Mikhail
2013-01-01
A.Y. Chtchelkanova, D.M. Treger, Spintronics: A Spin-Based29] R. Jansen, Silicon spintronics, Nature Materials, 11 (Zutic, New moves of the spintronics tango, Nature Materials,
Dependence of nuclear spin singlet lifetimes on RF spin-locking power
Stephen J. DeVience; Ronald L. Walsworth; Matthew S. Rosen
2012-01-06
We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.
Dependence of nuclear spin singlet lifetimes on RF spin-locking power
DeVience, Stephen J; Rosen, Matthew S
2012-01-01
We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.
Finite temperature spin-dynamics and phase transitions in spin-orbital models
Chen, C.-C.
2010-04-29
We study finite temperature properties of a generic spin-orbital model relevant to transition metal compounds, having coupled quantum Heisenberg-spin and Ising-orbital degrees of freedom. The model system undergoes a phase transition, consistent with that of a 2D Ising model, to an orbitally ordered state at a temperature set by short-range magnetic order. At low temperatures the orbital degrees of freedom freeze-out and the model maps onto a quantum Heisenberg model. The onset of orbital excitations causes a rapid scrambling of the spin spectral weight away from coherent spin-waves, which leads to a sharp increase in uniform magnetic susceptibility just below the phase transition, reminiscent of the observed behavior in the Fe-pnictide materials.
Pharmacia Spin Column Protocol Leslie Vosshall
Reactions or Riboprobes 1. Invert column and gently vortex to resuspend the resin. 2. Snap off bottom of column at perforation. 3. Loosen lid ½ turn and place column into a clean microcentrifuge tube. 4. Spin microcentrifuge tube. 7. Load sample. Be sure to dispense into the resin bed, not around the sides of the tube. 8
Spin Control for Ultracold Neutrons Jeff Martin
Martin, Jeff
to make lots of neutrons: Liberate them from nuclei! 1) In a nuclear reactor (fission). 2 Spin Control for Ultracold Neutrons Jeff Martin The University of Winnipeg August 2009 research Ridge, Tennessee, www.sns.gov ReactorAccelerator #12;How to make UCN Liberate neutrons
Spin-isospin stability of nuclear matter
N. Kaiser
2006-01-31
We calculate the density-dependent spin-isospin asymmetry energy $J(k_f)$ of nuclear matter in the three-loop approximation of chiral perturbation theory. The interaction contributions to $J(k_f)$ originate from one-pion exchange, iterated one-pion exchange, and irreducible two-pion exchange with no, single, and double virtual $\\Delta$-isobar excitation. We find that the approximation to $1\\pi$-exchange and iterated $1\\pi$-exchange terms (which leads already to a good nuclear matter equation of state by adjusting an emerging contact-term) is spin-isospin stable, since $J(k_{f0})\\simeq 24 {\\rm MeV}>0$. The inclusion of the chiral $\\pi N\\Delta$-dynamics, necessary in order to guarantee the spin-stability of nuclear matter, keeps this property intact. The corresponding spin-isospin asymmetry energy $J(k_f)$ stays positive even for extreme values of an undetermined short-distance parameter $J_5$ (whose possible range we estimate from realistic NN-potentials). The largest positive contribution to $J(k_f)$ (a term linear in density) comes from a two-body contact-term with its strength fitted to the empirical nuclear matter saturation point.
Quantum Spin Hall Effect in Silicene
Liu, Cheng-Cheng; Yao, Yugui
2011-01-01
Recent years have witnessed great interest in the quantum spin Hall effect (QSHE) which is a new quantum state of matter with nontrivial topological property due to the scientific importance as a novel quantum state and the technological applications in spintronics. Taking account of Si, Ge significant importance as semiconductor material and intense interest in the realization of QSHE for spintronics, here we investigate the spin-orbit opened energy gap and the band topology in recently synthesized silicene using first-principles calculations. We demonstrate that silicene with topologically nontrivial electronic structures can realize QSHE by exploiting adiabatic continuity and direct calculation of the Z2 topological invariant. We predict that QSHE in silicene can be observed in an experimentally accessible low temperature regime with the spin-orbit band gap of 1.55 meV, much higher than that of graphene due to large spin-orbit coupling and the low-buckled structure. Furthermore, we find that the gap will i...
Bett, Philip E
2015-01-01
We expand our previous study on the relationship between changes in the orientation of the angular momentum vector of dark matter haloes ("spin flips") and changes in their mass (Bett & Frenk 2012), to cover the full range of halo masses in a simulation cube of length 100 $h^{-1}$ Mpc. Since strong disturbances to a halo (such as might be indicated by a large change in the spin direction) are likely also to disturb the galaxy evolving within, spin flips could be a mechanism for galaxy morphological transformation without involving major mergers. We find that 35% of haloes have, at some point in their lifetimes, had a spin flip of at least $45\\deg$ that does not coincide with a major merger. Over 75% of large spin flips coincide with non-major mergers; only a quarter coincide with major mergers. We find a similar picture for changes to the inner-halo spin orientation, although here there is an increased likelihood of a flip occurring. Changes in halo angular momentum orientation, and other such measures of...
Measuring nonequilibrium retarded spin-spin Green's functions in an ion-trap based quantum simulator
Bryce T. Yoshimura; J. K. Freericks
2015-12-16
Recent work proposed a variant on Ramsey interferometry for coupled spin-$1/2$ systems that directly measures the retarded spin-spin Green's function. We expand on that work by investigating nonequilibrium retarded spin-spin Green's functions within the transverse-field Ising model. We derive the lowest four spectral moments to understand the short-time behavior and we employ a Lehmann-like representation to determine the spectral behavior. We simulate a Ramsey protocol for a nonequilibrium quantum spin system that consists of a coherent superposition of the ground state and diabatically excited higher-energy states via a temporally ramped transverse magnetic field. We then apply the Ramsey spectroscopy protocol to the final Hamiltonian, which has a constant transverse field. The short-time behavior directly relates to Lieb-Robinson bounds for the transport of many-body correlations, while the long-time behavior relates to the excitation spectra of the Hamiltonian. Compressive sensing is employed in the data analysis to efficiently extract that spectra.
Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets
Jeffrey E. McClintock; Ramesh Narayan; James F. Steiner
2013-06-28
The spins of ten stellar black holes have been measured using the continuum-fitting method. These black holes are located in two distinct classes of X-ray binary systems, one that is persistently X-ray bright and another that is transient. Both the persistent and transient black holes remain for long periods in a state where their spectra are dominated by a thermal accretion disk component. The spin of a black hole of known mass and distance can be measured by fitting this thermal continuum spectrum to the thin-disk model of Novikov and Thorne; the key fit parameter is the radius of the inner edge of the black hole's accretion disk. Strong observational and theoretical evidence links the inner-disk radius to the radius of the innermost stable circular orbit, which is trivially related to the dimensionless spin parameter a_* of the black hole (|a_*| 0.95. The robustness of the method is demonstrated by the dozens or hundreds of independent and consistent measurements of spin that have been obtained for several black holes, and through careful consideration of many sources of systematic error. Among the results discussed is a dichotomy between the transient and persistent black holes; the latter have higher spins and larger masses. Also discussed is recently discovered evidence in the transient sources for a correlation between the power of ballistic jets and black hole spin.
Otani, Yoshichika
Spin Valve System Jean Tarun1;2 , Shaoyun Huang1Ã , Yasuhiro Fukuma1 , Hiroshi Idzuchi1;5 , Yoshi, 2012; accepted February 22, 2012; published online March 16, 2012 A huge nonlocal spin valve signal over 700 has been observed in silicon-nanowire-based lateral spin valve with permalloy electrodes
Birge, Norman
valve geometry Charles E. Moreaua Department of Physics, Albion College, Albion, Michigan 49224 Ion C exchange-biased spin valve geometry that inserts a Ni "spoiler" layer into a Py/Cu/Py spin valve. Fits In the context of ferromagnetic/nonmagnetic F/N multilayers or spin valves, the size of the giant
Cui, Li-Ling [Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083 (China); School of Science, Hunan University of Technology, Zhuzhou 412007 (China); Yang, Bing-Chu, E-mail: bingchuyang@csu.edu.cn; Li, Xin-Mei; Cao, Can [Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083 (China); Long, Meng-Qiu, E-mail: mqlong@csu.edu.cn [Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083 (China); Department of Physics and Materials Science, City University of Hong Kong, Hong Kong (China)
2014-07-21
Spin-dependent transport properties of nanodevices constructed by iron-phthalocyanine (FePc) molecule sandwiched between two zigzag graphene nanoribbon electrodes are studied using first-principles quantum transport calculations. The effects of the symmetry and spin configuration of electrodes have been taken into account. It is found that large magnetoresistance, large spin polarization, dual spin-filtering, and negative differential resistance (NDR) can coexist in these devices. Our results show that 5Z-FePc system presents well conductive ability in both parallel (P) and anti-parallel (AP) configurations. For 6Z-FePc-P system, spin filtering effect and large spin polarization can be found. A dual spin filtering and NDR can also be shown in 6Z-FePc-AP. Our studies indicate that the dual spin filtering effect depends on the orbitals symmetry of the energy bands and spin mismatching of the electrodes. And all the effects would open up possibilities for their applications in spin-valve, spin-filter as well as effective spin diode devices.
Otani, Yoshichika
Spin transfer switching in current-perpendicular-to-plane spin valve observed by magneto-perpendicular-to-plane spin-valve device. The device consists of three spin-valve elements, each of which comprises-perpendicular-to- plane CPP spin-valve device has been directly observed by using a time resolved x-ray microscopy7 while
Aeschlimann, Martin
injection via Schottky contacts. Only recently, direct electrical spin injec- tion with organicSpin injection and spin dynamics at the CuPc/GaAs interface studied with ultraviolet photoemission show a highly efficient spin injection of hot electrons from GaAs into CuPc, demonstrating that spin
Phase Transitions in Continuum Ferromagnets with Unbounded Spins
Alexei Daletskii; Yuri Kondratiev; Yuri Kozitsky
2015-05-09
States of thermal equilibrium of an infinite system of interacting particles in a Euclidean space are studied. The particles bear 'unbounded' spins with a given symmetric a priori distribution. The interaction between the particles is pairwise and splits into position-position and spin-spin parts. The position-position part is described by a superstable potential, and the spin-spin part is attractive and of finite range. Thermodynamic states of the system are defined as tempered Gibbs measures on the space of marked configurations. It is proved that the set of such measures contains at least two elements if the activity is big enough.
A quantum mechanical description of particle spin rotation in channeling
Silenko, A.Ya.
1995-04-01
Spin rotation of spin-1/2 particles involved in planar channeling in straight and bent crystals is described in a consistent quantum mechanical manner. This is done by solving the Dirac equation in the Foldy-Wouthuysen representation, constructing an operator equation of motion for the spin, and calculating the average value of the spin precession frequency. For the case of channeling in bent crystals agreement is observed between the classical and quantum mechanical expressions, provided that the field of the planes is approximated by a harmonic potential. The effect of spin rotation in straight crystals is also examined. 17 refs.
Electrical detection of spin echoes for phosphorus donors in silicon
Hans Huebl; Felix Hoehne; Benno Grolik; Andre R. Stegner; Martin Stutzmann; Martin S. Brandt
2007-12-02
The electrical detection of spin echoes via echo tomography is used to observe decoherence processes associated with the electrical readout of the spin state of phosphorus donor electrons in silicon near a SiO$_2$ interface. Using the Carr-Purcell pulse sequence, an echo decay with a time constant of $1.7\\pm0.2 \\rm{\\mu s}$ is observed, in good agreement with theoretical modeling of the interaction between donors and paramagnetic interface states. Electrical spin echo tomography thus can be used to study the spin dynamics in realistic spin qubit devices for quantum information processing.
Spin transition in a four-coordinate iron oxide
Kawakami, T. [Nihon University, Tokyo; Sutou, S. [Nihon University, Tokyo; Hirama, H. [Nihon University, Tokyo; Sekiya, Y. [Nihon University, Tokyo; Makino, T. [Nihon University, Tokyo; Tsujimoto, Y. [Kyoto University, Japan; Kitada, A. [Kyoto University, Japan; Tassel, C. [Kyoto University, Japan; Kageyama, H. [Kyoto University, Japan; Yoshimura, K. [Kyoto University, Japan; Chen, Xingqiu [ORNL; Fu, Chong Long [ORNL; Okada, T. [University of Tokyo, Tokyo, Japan; Yagi, T. [University of Tokyo, Tokyo, Japan; Hayashi, N. [Kyoto University, Japan; Nasu, S. [Osaka University; Podloucky, R. [Institut fur Physikalische Chemie der RWTH; Takano, M. [Kyoto University, Japan
2009-01-01
The spin transition, or spin crossover, is a manifestation of electronic instability induced by external constraints such as pressure1. Among known examples that exhibit spin transition, 3d ions with d6 electron configurations represent the vast majority, but the spin transition observed thus far has been almost exclusively limited to that between high-spin (S = 2) and low-spin (S = 0) states2-9. Here we report a novel high-spin to intermediate-spin (S = 1) state transition at 33 GPa induced by pressurization of an antiferromagnetic insulator SrFeO2 with a square planar coordination10. The change in spin multiplicity brings to ferromagnetism as well as metallicity, yet keeping the ordering temperature far above ambient. First-principles calculations attribute the origin of the transition to the strong inlayer hybridization between Fe dx 2 -y 2 O p , leading to a pressure-induced electronic instability toward the depopulation of Fe dx 2 -y 2 O p antibonding states. Furthermore, the ferromagnetic S = 1 state is half-metallic due to the inception of half-occupied spin-down (dxz, dyz) degenerate states upon spin transition. These results highlight the square-planar coordinated iron oxides as a new class of magnetic and electric materials and provide new avenues toward realizing multi-functional sensors and data-storage devices.
Accurate and efficient spin integration for particle accelerators
Abell, Dan T; Ranjbar, Vahid H; Barber, Desmond P
2015-01-01
Accurate spin tracking is a valuable tool for understanding spin dynamics in particle accelerators and can help improve the performance of an accelerator. In this paper, we present a detailed discussion of the integrators in the spin tracking code gpuSpinTrack. We have implemented orbital integrators based on drift-kick, bend-kick, and matrix-kick splits. On top of the orbital integrators, we have implemented various integrators for the spin motion. These integrators use quaternions and Romberg quadratures to accelerate both the computation and the convergence of spin rotations. We evaluate their performance and accuracy in quantitative detail for individual elements as well as for the entire RHIC lattice. We exploit the inherently data-parallel nature of spin tracking to accelerate our algorithms on graphics processing units.
A spinning mirror for fast angular scans of EBW emission for magnetic pitch profile measurements
Volpe, Francesco [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)
2010-10-15
A tilted spinning mirror rapidly steers the line of sight of the electron Bernstein wave (EBW) emission radiometer at the Mega-Amp Spherical Tokamak (MAST). In order to resist high mechanical stresses at rotation speeds of up to 12 000 rpm and to avoid eddy current induced magnetic braking, the mirror consists of a glass-reinforced nylon substrate of a special self-balanced design, coated with a reflecting layer. By completing an angular scan every 2.5-10 ms, it allows one to characterize with good time resolution the Bernstein-extraordinary-ordinary mode-conversion efficiency as a function of the view angles. Angular maps of conversion efficiency are directly related to the magnetic pitch angle at the cutoff layer for the ordinary mode. Hence, measurements at various frequencies provide the safety factor profile at the plasma edge. Initial measurements and indications of the feasibility of the diagnostic are presented. Moreover, angular scans indicate the best launch conditions for EBW heating.
Eslami, Leila, E-mail: Leslami@iust.ac.ir; Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Tehran 16846 (Iran, Islamic Republic of)
2014-02-28
Spin-dependent electron transport in an open double quantum ring, when each ring is made up of four quantum dots and threaded by a magnetic flux, is studied. Two independent and tunable gate voltages are applied to induce Rashba spin-orbit effect in the quantum rings. Using non-equilibrium Green's function formalism, we study the effects of electron-electron interaction on spin-dependent electron transport and show that although the electron-electron interaction induces an energy gap, it has no considerable effect when the bias voltage is sufficiently high. We also show that the double quantum ring can operate as a spin-filter for both spin up and spin down electrons. The spin-polarization of transmitted electrons can be tuned from ?1 (pure spin-down current) to +1 (pure spin-up current) by changing the magnetic flux and/or the gates voltage. Also, the double quantum ring can act as AND and NOR gates when the system parameters such as Rashba coefficient are properly adjusted.
Electrical spin injection using GaCrN in a GaN based spin light emitting diode
Banerjee, D.; Ganguly, S.; Saha, D.; Adari, R.; Sankaranarayan, S.; Kumar, A.; Aldhaheri, R. W.; Hussain, M. A.; Balamesh, A. S.
2013-12-09
We have demonstrated electrical spin-injection from GaCrN dilute magnetic semiconductor (DMS) in a GaN-based spin light emitting diode (spin-LED). The remanent in-plane magnetization of the thin-film semiconducting ferromagnet has been used for introducing the spin polarized electrons into the non-magnetic InGaN quantum well. The output circular polarization obtained from the spin-LED closely follows the normalized in-plane magnetization curve of the DMS. A saturation circular polarization of ?2.5% is obtained at 200?K.
Long-lived states with well-defined spins in spin-$1/2$ homogeneous Bose gases
Yurovsky, Vladimir A
2015-01-01
Many-body eigenfunctions of the total spin operator can be constructed from the spin and spatial wavefunctions with non-trivial permutation symmetries. Spin-dependent interactions can lead to relaxation of the spin eigenstates to the thermal equilibrium. The relaxation rate is evaluated here for two- and three-dimensional gases using the chaotic behavior of the thermally-equilibrium spatial state. Dependence of the rate on the total spin and its projection is separated into a factor, which is independent of the gas dimensionality, temperature, and density. This factor can be controlled by a Feshbach resonance, leading to suppression of the relaxation rate by several orders of magnitude.
Jung, Paul
NSF-CBMS Conference on Quantum Spin SystemsNSF-CBMS Conference on Quantum Spin SystemsNSF-CBMS Conference on Quantum Spin SystemsNSF-CBMS Conference on Quantum Spin SystemsNSF-CBMS Conference on QuantumUniversity of Alabama at Birmingham June 1620, 2014 Conference organizers: Paul Jung Shannon Starr Gunter Stolz Invited
All-electrical time-resolved spin generation and spin manipulation in n-InGaAs
Stepanov, I.; Kuhlen, S.; Ersfeld, M.; Beschoten, B., E-mail: bernd.beschoten@physik.rwth-aachen.de [2nd Institute of Physics and JARA-FIT, RWTH Aachen University, D-52074 Aachen (Germany); Lepsa, M. [Peter Grünberg Institut (PGI-9) and JARA-FIT, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany)
2014-02-10
We demonstrate all-electrical spin generation and subsequent manipulation by two successive electric field pulses in an n-InGaAs heterostructure in a time-resolved experiment at zero external magnetic field. The first electric field pulse along the [11{sup ¯}0] crystal axis creates a current-induced spin polarization (CISP) which is oriented in the plane of the sample. The subsequent electric field pulse along [110] generates a perpendicular magnetic field pulse leading to a coherent precession of this spin polarization with 2-dimensional electrical control over the final spin orientation. Spin precession is probed by time-resolved Faraday rotation. We determine the build-up time of CISP during the first field pulse and extract the spin dephasing time and internal magnetic field strength during the spin manipulation pulse.
Nimbalkar, Manoj; Neves, Jorge L; Elavarasi, S Begam; Yuan, Haidong; Khaneja, Navin; Dorai, Kavita; Glaser, Steffen J
2011-01-01
We study multiple-spin coherence transfers in linear Ising spin chains with nearest neighbor couplings. These constitute a model for efficient information transfers in future quantum computing devices and for many multi-dimensional experiments for the assignment of complex spectra in nuclear magnetic resonance spectroscopy. We complement prior analytic techniques for multiple-spin coherence transfers with a systematic numerical study where we obtain strong evidence that a certain analytically-motivated family of restricted controls is sufficient for time-optimality. In the case of a linear three-spin system, additional evidence suggests that prior analytic pulse sequences using this family of restricted controls are time-optimal even for arbitrary local controls. In addition, we compare the pulse sequences for linear Ising spin chains to pulse sequences for more realistic spin systems with additional long-range couplings between non-adjacent spins. We experimentally implement the derived pulse sequences in th...