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Sample search results for: crystals efeito aharonov-bohm

 

1

Aharonov-Bohm Radiation

  HEP - Theory (arXiv)

Summary: A solenoid oscillating in vacuum will pair produce charged particles due to the Aharonov-Bohm (AB) interaction. We calculate the radiation pattern and power emitted for charged scalar particles. We extend the solenoid analysis to cosmic strings, and find enhanced radiation from cusps and kinks on loops. We argue by analogy with the electromagnetic AB interaction that cosmic strings should emit photons due to the gravitational AB interaction of fields in the conical spacetime of a cosmic string. We calculate the emission from a kink and find that it is of similar order as emission from a cusp, but kinks are vastly more numerous than cusps and may provide a more interesting observational signature.

Katherine Jones-Smith; Harsh Mathur; Tanmay Vachaspati
2010-01-25

2

Locality and topology in the molecular Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: It is shown that the molecular Aharonov-Bohm effect is neither nonlocal nor topological in the sense of the standard magnetic Aharonov-Bohm effect. It is further argued that there is a close relationship between the molecular Aharonov-Bohm effect and the Aharonov-Casher effect for an electrically neutral spin$-{1/2}$ particle encircling a line of charge.

Erik Sjöqvist
2002-11-05

3

Electromagnetic potentials and Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: Hamilton-Jacobi equation which governs classical mechanics and electrodynamics explicitly depends on the electromagnetic potentials (A,{\\phi}), similar to Schroedinger equation. We derived the Aharonov-Bohm effect from Hamilton-Jacobi equation thereby having proved that this effect is of classical origin. These facts enable us to arrive at the following conclusions: a) the very idea of special role of potentials (A,{\\phi}) in quantum mechanics (different from their role in classical physics) lost the ground, and becomes dubious, as this idea is based on the Aharonov-Bohm effect, b) failure to find any signs of a special role of these potentials in the appropriate experiments (Feinberg, 1963) is thereby explained, and c) discovery of classical analogues of the Aharonov-Bohm effect (Berry et al., 1980) is also explained by a classical nature of this effect. Elucidation of the "unlocal" interaction problem was made.

Alexander Ershkovich
2013-04-10

4

Electromagnetic potentials and Aharonov-Bohm effect

  CERN Preprints

Summary: Hamilton-Jacobi equation which governs classical mechanics and electrodynamics explicitly depends on the electromagnetic potentials (A,{\\phi}), similar to Schroedinger equation. We derived the Aharonov-Bohm effect from Hamilton-Jacobi equation thereby having proved that this effect is of classical origin. These facts enable us to arrive at the following conclusions: a) the very idea of special role of potentials (A,{\\phi}) in quantum mechanics (different from their role in classical physics) lost the ground, and becomes dubious, as this idea is based on the Aharonov-Bohm effect, b) failure to find any signs of a special role of these potentials in the appropriate experiments (Feinberg, 1963) is thereby explained, and c) discovery of classical analogues of the Aharonov-Bohm effect (Berry et al., 1980) is also explained by a classical nature of this effect. Elucidation of the physical meaning of the magnetic potential A is offered.

Ershkovich, Alexander
2012-01-01

5

Relativistic Aharonov-Bohm-Coulomb Problem

  HEP - Theory (arXiv)

Summary: The Aharonov-Bohm effect is analyzed for a spin-1/2 particle in the case that a $1/r$ potential is present. Scalar and vector couplings are each considered. It is found that the approach in which the flux tube is given a finite radius that is taken to zero only after a matching of boundary conditions does not give physically meaningful results. Specifically, the operations of taking the limit of zero flux tube radius and the Galilean limit do not commute. Thus there appears to be no satisfactory solution of the relativistic Aharonov-Bohm-Coulomb problem using the finite radius flux tube method.

C. R. Hagen; D. K. Park
1994-10-28

6

Aharonov-Bohm scattering on a cone

  Physics (arXiv)

Summary: The Aharonov-Bohm scattering amplitude is calculated in the context of planar gravity with localized sources which also carry a magnetic flux. These sources cause space-time to develop conical singularities at their location, thus introducing novel effects in the scattering of electrically charged particles. The behaviour of the wave function in the proximity of the classical scattering directions is analyzed by means of an asymptotic expansion previously introduced by the author. It is found that, in contrast with the Aharonov-Bohm effect in flat space, integer values of the numerical flux can produce observable effects.

Marcos Alvarez
1998-04-27

7

Quantum Aharonov-Bohm Billiard System

  Nonlinear Sciences (arXiv)

Summary: The Green's functions of the two and three-dimensional relativistic Aharonov-Bohm (A-B) systems are given by the path integral approach. In addition the exact radial Green's functions of the spherical A-B quantum billiard system in two and three-dimensional are obtained via the perturbation techanique of $\\delta $-function.

Der-San Chuu; De-Hone Lin
1999-09-15

8

Hidden superconformal symmetry of spinless Aharonov-Bohm system

  Mathematical Physics (arXiv)

Summary: A hidden supersymmetry is revealed in the spinless Aharonov-Bohm problem. The intrinsic supersymmetric structure is shown to be intimately related with the scale symmetry. As a result, a bosonized superconformal symmetry is identified in the system. Different self-adjoint extensions of the Aharonov-Bohm problem are studied in the light of this superconformal structure and interacting anyons. Scattering problem of the original Aharonov-Bohm model is discussed in the context of the revealed supersymmetry.

Francisco Correa; Horacio Falomir; Vit Jakubsky; Mikhail S. Plyushchay
2010-02-02

9

Gravitational Dressing of Aharonov-Bohm Amplitudes

  HEP - Theory (arXiv)

Summary: We investigate Aharonov-Bohm scattering in a theory in which charged bosonic matter fields are coupled to topologically massive electrodynamics and topologically massive gravity. We demonstrate that, at one-loop order, the transmuted spins in this theory are related to the ones of ordinary Chern-Simons gauge theory in the same way that the Knizhnik-Polyakov-Zamolodchikov formula relates the Liouville-dressed conformal weights of primary operators to the bare weights in two-dimensional conformal field theories. We remark on the implications of this connection between two-dimensional conformal field theories and three-dimensional gauge and gravity theories for a topological membrane reformulation of strings. We also discuss some features of the gravitational analog of the Aharonov-Bohm effect.

G. Amelino-Camelia; I. I. Kogan; R. J. Szabo
1996-10-09

10

Aharonov-Bohm Effect in Noncommutative Spaces

  HEP - Theory (arXiv)

Summary: The Aharonov-Bohm effect on the noncommutative plane is considered. Developing the path integral formulation of quantum mechanics, we find the propagation amplitude for a particle in a noncommutative space. We show that the corresponding shift in the phase of the particle propagator due to the magnetic field of a thin solenoid receives certain gauge invariant corrections because of the noncommutativity. Evaluating the numerical value for this correction, an upper bound for the noncommutativity parameter is obtained.

M. Chaichian; A. Demichev; P. Presnajder; M. M. Sheikh-Jabbari; A. Tureanu
2001-04-30

11

Aharonov-Bohm Effect with $?$--type Interaction

  Mathematical Physics (arXiv)

Summary: A quantum particle interacting with a thin solenoid and a magnetic flux is described by a five-parameter family of Hamilton operators, obtained via the method of self-adjoint extensions. One of the parameters, the value of the flux, corresponds to the Aharonov-Bohm effect; the other four parameters correspond to the strength of a singular potential barrier. The spectrum and eigenstates are computed and the scattering problem is solved.

L. Dabrowski; P. Stovicek
1996-12-30

12

Noncommutativity and the Aharonov-Bohm Effect

  HEP - Theory (arXiv)

Summary: The possibility of detecting noncommutive space relics is analyzed by using the Aharonov-Bohm effect. If space is non-commutative, it turns out that the holonomy receives kinematical corrections that tend to diffuse the fringe pattern. This fringe pattern has a non-trivial energy dependence and, therefore, one could observe noncommutative effects by modifying the energy of the incident electrons beam in the Tonomura experimental arrangement

J. Gamboa; M. Loewe; J. C. Rojas
2001-11-07

13

Aharonov--Bohm Effect in 3D Abelian Higgs Theory

  HEP - Lattice (arXiv)

Summary: We study a field--theoretical analogue of the Aharonov--Bohm effect in the 3D Abelian Higgs Model: the corresponding topological interaction is proportional to the linking number of the vortex and the particle world trajectories. We show that the Aharonov--Bohm effect gives rise to a nontrivial interaction of tested charged particles.

M. N. Chernodub; F. V. Gubarev; M. I. Polikarpov
1996-08-14

14

Propagator for an Aharonov-Bohm-Coulomb system

  Quantum Physics (arXiv)

Summary: The propagator of three-dimensional Aharonov-Bohm-Coulomb system is calculated by following the Duru-Kleinert method. It is shown that the system is reduced to two independent two dimensional Aharonov-Bohm plus harmonic oscillator systems through dimensional extension and Kustaanheimo-Stiefel transformation. The energy spectrum is deduced.

D. K. Park; Sahng-Kyoon Yoo; Soo-Young Lee; Jae-Rok Kahng; Chang Soo Park; Eui-Soon Yim; C. H. Lee
1997-07-02

15

Optical Aharonov-Bohm effect: an inverse hyperbolic problems approach

  Mathematical Physics (arXiv)

Summary: We describe the general setting for the optical Aharonov-Bohm effect based on the inverse problem of the identification of the coefficients of the governing hyperbolic equation by the boundary measurements. We interpret the inverse problem result as a possibility in principle to detect the optical Aharonov-Bohm effect by the boundary measurements.

Gregory Eskin
2007-10-18

16

Optical theorem for Aharonov-Bohm scattering

  HEP - Theory (arXiv)

Summary: Quantum-mechanical scattering off a magnetic vortex is considered, and the optical theorem is derived. The vortex core is assumed to be impermeable to scattered particles, and its transverse size is taken into account. We show that the scattering Aharonov-Bohm effect is independent of the choice of boundary conditions from the variety of the Robin ones. The behaviour of the scattering amplitude in the forward direction is analyzed, and the persistence of the Fraunhofer diffraction in the short-wavelength limit is shown to be crucial for maintaining the optical theorem in the quasiclassical limit.

Yu. A. Sitenko; N. D. Vlasii
2011-07-14

17

Geometry of the Aharonov-Bohm Effect

  Mathematical Physics (arXiv)

Summary: We show that the connection responsible for any abelian or non abelian Aharonov-Bohm effect with $n$ parallel ``magnetic'' flux lines in $\\R^3$, lies in a trivial $G$-principal bundle $P\\to M$, i.e. $P$ is isomorphic to the product $M\\times G$, where $G$ is any path connected topological group; in particular a connected Lie group. We also show that two other bundles are involved: the universal covering space $\\tilde{M}\\to M$, where path integrals are computed, and the associated bundle $P\\times_G \\C^m \\to M$, where the wave function and its covariant derivative are sections.

R. S. Huerfano; M. A. Lopez; M. Socolovsky
2007-03-06

18

Relativistic scalar Aharonov-Bohm scattering

  HEP - Theory (arXiv)

Summary: We discuss the scattering of relativistic spin zero particles by an infinitely long and arbitrarily thin solenoid. The exact solution of the first-quantized problem can be obtained as a mimic of the nonrelativistic case, either in the original Aharonov-Bohm way or by using the Berry's magnetization scheme. The perturbative treatment is developed in the Feshbach-Villars two-component formalism for the Klein-Gordon equation and it is shown that it also requires renormalization as in the Schrodinger counterpart. The results are compared with those of the field theoretical approach which corresponds to the two-body sector of the scalar Chern-Simons theory.

M. Gomes; J. M. C. Malbouisson; A. G. Rodrigues; A. J. da Silva
2000-07-10

19

Deflating the Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: I argue that the metaphysical import of the Aharonov-Bohm effect has been overstated: correctly understood, it does not require either rejection of gauge invariance or any novel form of nonlocality. The conclusion that it does require one or the other follows from a failure to keep track, in the analysis, of the complex scalar field to which the magnetic vector potential is coupled. Once this is recognised, the way is clear to a local account of the ontology of electrodynamics (or at least, to an account no more nonlocal than quantum theory in general requires); I sketch a possible such account.

David Wallace
2014-07-18

20

Dynamics of the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The time-dependent Dirac equation is solved using the three-dimensional Finite Difference-Time Domain (FDTD) method. The dynamics of the electron wave packet in a vector potential is studied in the arrangements associated with the Aharonov-Bohm effect. The solution of the Dirac equation showed a change in the velocity of the electron wave packet even in a region where no fields of the unperturbed solenoid acted on the electron. The solution of the Dirac equation qualitatively agreed with the prediction of classical dynamics under the assumption that the dynamics was defined by the conservation of generalized or canonical momentum of the electron.

Neven Simicevic
2010-03-24

21

Aharonov-Bohm Radiation of Fermions

  HEP - Theory (arXiv)

Summary: We analyze Aharonov-Bohm radiation of charged fermions from oscillating solenoids and cosmic strings. We find that the angular pattern of the radiation has features that differ significantly from that for bosons. For example, fermionic radiation in the lowest harmonic is approximately isotropically distributed around an oscillating solenoid, whereas for bosons the radiation is dipolar. We also investigate the spin polarization of the emitted fermion-antifermion pair. Fermionic radiation from kinks and cusps on cosmic strings is shown to depend linearly on the ultraviolet cut-off, suggesting strong emission at an energy scale comparable to the string energy scale.

Yi-Zen Chu; Harsh Mathur; Tanmay Vachaspati
2010-08-21

22

The Electric Aharonov-Bohm Effect

  CERN Preprints

Summary: In their seminal paper Aharonov and Bohm (1959) claimed that electromagnetic fields can act at a distance on charged particles even if they are identically zero in the region of space where the particles propagate. They proposed two experiments to verify their theoretical conclusions. The magnetic effect, that has been extensively studied, and the electric effect where an electron is affected by a time-dependent electric potential that is constant in the region where the electron is propagating, i.e., such that the electric field vanishes along its trajectory. The Aharonov-Bohm effects imply such a strong departure from the physical intuition coming from classical physics that it is no wonder that they remain a highly controversial issue, after more than fifty years. The existence of electric Aharonov-Bohm effect, that has not been confirmed experimentally, is a very controversial issue. In their 1959 paper Aharonov and Bohm proposed an Ansatz for the solution to the Schroedinger equation in regions where the...

Weder, Ricardo
2010-01-01

23

Aharonov--Bohm Effect in the Abelian Higgs Theory

  HEP - Lattice (arXiv)

Summary: We study a field--theoretical analogue of the Aharonov--Bohm effect in the Abelian Higgs Model: the corresponding topological interaction is proportional to the linking number of the Abrikosov--Nielsen--Olesen string world sheets and the particle world trajectory. The creation operators of the strings are explicitly constructed in the path integral and in the Hamiltonian formulation of the theory. We show that the Aharonov--Bohm effect gives rise to several nontrivial commutation relations. We also study the Aharonov--Bohm effect in the lattice formulation of the Abelian Higgs Model. It occurs that this effect gives rise to a nontrivial interaction of tested charged particles.

M. N. Chernodub; M. I. Polikarpov
1995-11-01

24

The optical Aharonov-Bohm effect Polarization effects in the opticalPolarization effects in the optical AharonovAharonov--BohmBohm

  Physics Websites

Summary: The optical Aharonov-Bohm effect Polarization effects in the opticalPolarization effects in the optical AharonovAharonov--BohmBohm oscillations in quantum rings.oscillations in quantum rings. Luis Dias. · A net Aharonov-Bohm phase arises signatures in the optical emission and absorption of the Optical AB

Dias, Luis Gregório

25

New formulae for the Aharonov-Bohm wave operators

  Mathematical Physics (arXiv)

Summary: It is proved that the wave operators corresponding to Schroedinger operators with Aharonov-Bohm type magnetic fields can be rewritten in terms of explicit functions of the generator of dilations and of the Laplacian.

S. Richard
2008-11-24

26

The Aharonov-Bohm Effect in the Momentum Space

  Quantum Physics (arXiv)

Summary: The Schrodinger formalism of quantum mechanics is used to demonstrate the existence of the Aharonov-Bohm effect in momentum space and set-ups for experimentally demonstrating it are proposed for either free or ballistic electrons.

D. Dragoman; S. Bogdan
2005-03-21

27

The deconfinement phase transition as an Aharonov-Bohm effect

  HEP - Theory (arXiv)

Summary: A subjective and incomplete list of interesting and unique features of the deconfinement phase transition is presented. Furthermore a formal similarity of the density matrix of the Aharonov-Bohm system and QCD is mentioned, as well.

Janos Polonyi
1999-06-27

28

Unitarity of the Aharonov-Bohm Scattering Amplitudes

  HEP - Theory (arXiv)

Summary: We discuss the unitarity relation of the Aharonov-Bohm scattering amplitude with the hope that it distinguishes between the differing treatments which employ different incident waves. We find that the original Aharonov-Bohm scattering amplitude satisfies the unitarity relation under the regularization prescription whose theoretical foundation does not appear to be understood. On the other hand, the amplitude obtained by Ruijsenaars who uses plane wave as incident wave also satisfies the unitarity relation but in an unusual way.

Masato Arai; Hisakazu Minakata
1998-08-09

29

The Aharonov-Bohm Effect in Noncommutative Quantum Mechanics

  HEP - Theory (arXiv)

Summary: The Aharonov-Bohm (AB) effect in non-commutative quantum mechanics (NCQM) is studied. First, by introducing a shift for the magnetic vector potential we give the Schr$\\ddot{o}$dinger equations in the presence of a magnetic field on NC space and NC phase space, respectively. Then by solving the Schr$\\ddot{o}$dinger equations, we obtain the Aharonov-Bohm (AB) phase on NC space and NC phase space, respectively.

Kang Li; Sayipjamal Dulat
2006-08-13

30

Classical Electrodynamics without Fields and the Aharonov-Bohm effect

  Physics (arXiv)

Summary: The Darwin-Breit Hamiltonian is applied to the Aharonov-Bohm experiment. In agreement with the standard Maxwell-Lorentz theory, the force acting on electrons from infinite solenoids or ferromagnetic rods vanishes. However, the interaction energies and phase factors of the electron wave packets are non-zero. This allows us to explain the Aharonov-Bohm effect without involvement of electromagnetic potentials, fields, and topological properties of space.

Eugene V. Stefanovich
2008-03-19

31

Relativistic Corrections to the Aharonov-Bohm Scattering

  HEP - Theory (arXiv)

Summary: We determine the |p|/m expansion of the two body scattering amplitude of the quantum theory of a Chern-Simons field minimally coupled to a scalar field with quartic self-interaction. It is shown that the existence of a critical value of the self-interaction parameter for which the 2-particle amplitude reduces to the Aharonov-Bohm one is restricted to the leading, nonrelativistic, order. The subdominant terms correspond to relativistic corrections to the Aharonov-Bohm scattering.

M. Gomes; J. M. C. Malbouisson; A. J. da Silva
1996-11-05

32

Aharonov-Bohm effect in a Class of Noncommutative Theories

  HEP - Theory (arXiv)

Summary: The Aharonov-Bohm effect including spin-noncommutative effects is considered. At linear order in $\\theta$, the magnetic field is gauge invariant although spatially strongly anisotropic. Despite this anisotropy, the Schr\\"odinger-Pauli equation is separable through successive unitary transformations and the exact solution is found. The scattering amplitude is calculated and compared with the usual case. In the noncommutative Aharonov-Bohm case the differential cross section is independent of $\\theta$.

A. Das; H. Falomir; J. Gamboa; F. Mendez; M. Nieto
2011-05-09

33

Quantum Computation with Aharonov-Bohm Qubits

  Quantum Physics (arXiv)

Summary: We analyze the posibility of employing the mesoscopic-nanoscopic ring of a normal metal in a doubly degenerate persistent current state with a third auxihilary level and in the presence of the Aharonov-Bohm flux equal to the half of the normal flux quantum $\\hbar c/e$ as a qubit. The auxiliary level can be effectively used for all fundamental quantum logic gate (qu-gate) operations which includes the initialization, phase rotation, bit flip and the Hadamard transformation as well as the double-qubit controlled operations (conditional bit flip). We suggest a tentative realization of the mechanism as either the mesoscopic structure of three quantum dots coherently coupled by mesoscopic tunnelling in crossed magnetic and electric fields, or as a nanoscopic structure of triple anionic vacancy (similar to $F_3$ centers in alkali halides) with one trapped electron in one spin projection state.

A. Barone; T. Hakioglu; I. O. Kulik
2002-03-02

34

Aharonov-Bohm effect with many vortices

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm effect is the prime example of a zero-field-strength configuration where a non-trivial vector potential acquires physical significance, a typical quantum mechanical effect. We consider an extension of the traditional A-B problem, by studying a two-dimensional medium filled with many point-like vortices. Systems like this might be present within a Type II superconducting layer in the presence of a strong magnetic field perpendicular to the layer, and have been studied in different limits. We construct an explicit solution for the wave function of a scalar particle moving within one such layer when the vortices occupy the sites of a square lattice and have all the same strength, equal to half of the flux quantum. From this construction we infer some general characteristics of the spectrum, including the conclusion that such a flux array produces a repulsive barrier to an incident low-energy charged particle, so that the penetration probability decays exponentially with distance from the edge.

Fabio Franchini; Alfred Scharff Goldhaber
2008-10-08

35

Relativistic Aharonov--Bohm effect in the presence of two-dimensional Coulomb potential

  Quantum Physics (arXiv)

Summary: We obtain exact solutions to the Dirac equation and the relevant binding energies in the combined Aharonov--Bohm--Coulomb potential in 2+1 dimensions. By means of solutions obtained the quantum Aharonov--Bohm effect is studied for free and bound electron states. We show that the total scattering amplitude in the combined Aharonov--Bohm--Coulomb potential is a sum of the Aharonov--Bohm and the Coulomb scattering amplitudes. This modifies expression for the standard Aharonov--Bohm cross section due to the interference these two amplitudes with each other.

Vladislav Khalilov
2004-06-04

36

Testing spatial noncommutativiy via the Aharonov-Bohm effect

  HEP - Theory (arXiv)

Summary: The possibility of detecting noncommutative space relics is analyzed using the Aharonov-Bohm effect. We show that, if space is noncommutative, the holonomy receives non-trivial kinematical corrections that will produce a diffraction pattern even when the magnetic flux is quantized. The scattering problem is also formulated, and the differential cross section is calculated. Our results can be extrapolated to high energy physics and the bound $\\theta \\sim [ 10 {TeV}]^{-2}$ is found. If this bound holds, then noncommutative effects could be explored in scattering experiments measuring differential cross sections for small angles. The bound state Aharonov- Bohm effect is also discussed.

H. Falomir; J. Gamboa; M. Loewe; F. Mendez; J. C. Rojas
2002-06-14

37

Effect of Aharonov-Bohm Phase on Spin Tunneling

  Quantum Physics (arXiv)

Summary: The role of Aharonov-Bohm effect in quantum tunneling is examined when a potential is defined on the $S^1$ and has $N$-fold symmetry. We show that the low-lying energy levels split from the $N$-fold degenerate ground state oscillate as a function of the Aharonov-Bohm phase, from which general degeneracy conditions depending on the magnetic flux is obtained. We apply these results to the spin tunneling in a spin system with $N$-fold rotational symmetry around a hard axis.

ChangSoo Park; D. K. Park
2000-08-11

38

Aharonov-Bohm magnetism and Landau diamagnetism in semimetals

  Mathematical Physics (arXiv)

Summary: We compute the magnetic response of hollow semimetal cylinders and rings to the presence of an axial Aharonov-Bohm magnetic flux, in the absence of interactions. We predict nullification of the Aharonov-Bohm effect for a class of dispersion laws that includes "non-relativistic" dispersion and demonstrate that at zero flux the ground-state of a very short "armchair" graphene tube will exhibit a ferromagnetic broken symmetry. We also compute the diamagnetic response of bulk semimetals to the presence of a uniform magnetic field, specifically predicting that the susceptibility has a logarithmic dependence on the size of the sample.

Eugene B. Kolomeisky; Joseph P. Straley
2011-12-29

39

Generalized Aharonov-Bohm effect, homotopy classes and Hausdorff dimension

  Quantum Physics (arXiv)

Summary: We suggest as gedanken experiment a generalization of the Aharonov-Bohm experiment, based on an array of solenoids. This experiment allows in principle to measure the decomposition into homotopy classes of the quantum mechanical propagator. This yields information on the geometry of the average path of propagation and allows to determine its Hausdorff dimension.

H. Kr{ö}ger
1997-01-31

40

Spectral and scattering theory for the Aharonov-Bohm operators

  Mathematical Physics (arXiv)

Summary: We review the spectral and the scattering theory for the Aharonov-Bohm model on R^2. New formulae for the wave operators and for the scattering operator are presented. The asymptotics at high and at low energy of the scattering operator are computed.

K. Pankrashkin; S. Richard
2009-12-01

41

The Aharonov-Bohm effect for a knotted magnetic solenoid

  HEP - Theory (arXiv)

Summary: We show that the linking of a semiclassical path of a charged particle with a knotted magnetic solenoid results in the Aharonov-Bohm effect. The phase shift in the wave function is proportional to the flux intersecting a certain connected and orientable surface bounded by the knot (a Seifert surface of the knot).

Roman V. Buniy; Thomas W. Kephart
2008-08-13

42

Putting a Spin on the Aharonov-Bohm Oscillations

  Quantum Physics (arXiv)

Summary: An experiment that shows the modulation of the Aharonov-Bohm oscillations of magneto-resistance in a mesoscopic ring is described. Possible theoretical explanations of this modulation due to the interaction of the electron spin with the magnetic and electric fields are considered.

Jeeva Anandan
2002-12-17

43

Aharonov-Bohm Scattering, Contact Interactions and Scale Invariance

  HEP - Theory (arXiv)

Summary: We perform a perturbative analysis of the Aharonov-Bohm problem to one loop in a field-theoretic formulation, and show that contact interactions are necessary for renormalizability. In general, the classical scale invariance of this problem is broken quantum mechanically. There exists however a critical point for which this anomaly disappears.

O. Bergman; G. Lozano
1993-02-24

44

Perturbative Analysis of Nonabelian Aharonov-Bohm Scattering

  HEP - Theory (arXiv)

Summary: We perform a perturbative analysis of the nonabelian Aharonov-Bohm problem to one loop in a field theoretic framework, and show the necessity of contact interactions for renormalizability of perturbation theory. Moreover at critical values of the contact interaction strength the theory is finite and preserves classical conformal invariance.

Dongsu Bak; Oren Bergman
1994-03-18

45

Aharonov-Bohm effect on the Poincaré disk

  Mathematical Physics (arXiv)

Summary: We consider formal quantum hamiltonian of a charged particle on the Poincar\\'e disk in the presence of an Aharonov-Bohm magnetic vortex and a uniform magnetic field. It is shown that this hamiltonian admits a four-parameter family of self-adjoint extensions. Its resolvent and the density of states are calculated for natural values of the extension parameters.

O. Lisovyy
2007-03-02

46

Spectroscopic version of the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: An experiment is proposed in which the Aharonov-Bohm effect can be veryfied through a spectroscopic measurement. The apparatus consists of gaseous hydrochloric acid (HCl) immersed in the constant vector potential ${\\bf A}=A_0{\\bf z}$ present in the interior of a toroidal coil. Changes due to ${\\bf A}$ in the absorption spectrum of the gas are investigated.

C. Laganá
2014-03-21

47

Zero modes in a system of Aharonov-Bohm fluxes

  Mathematical Physics (arXiv)

Summary: We study zero modes of two-dimensional Pauli operators with Aharonov--Bohm fluxes in the case when the solenoids are arranged in periodic structures like chains or lattices. We also consider perturbations to such periodic systems which may be infinite and irregular but they are always supposed to be sufficiently scarce.

V. A. Geyler; P. Stovicek
2004-12-31

48

Symmetry-protected many-body Aharonov-Bohm effect

  MIT - DSpace

Summary: It is known as a purely quantum effect that a magnetic flux affects the real physics of a particle, such as the energy spectrum, even if the flux does not interfere with the particle's path—the Aharonov-Bohm effect. Here ...

Santos, Luiz H.

49

Group-Theoretical Derivation of Aharonov-Bohm Phase Shifts

  Mathematical Physics (arXiv)

Summary: The phase shifts of the Aharonov-Bohm effect are generally determined by means of the partial wave decomposition of the underlying Schrodinger equation. It is shown here that they readily emerge from an o(2,1) calculation of the energy levels employing an added harmonic oscillator potential which discretizes the spectrum.

C. R. Hagen
2012-11-16

50

The Aharonov--Bohm effect in scattering theory

  HEP - Theory (arXiv)

Summary: The Aharonov--Bohm effect is considered as a scattering event with nonrelativistic charged particles of the wavelength which is less than the transverse size of an impenetrable magnetic vortex. The quasiclassical WKB method is shown to be efficient in solving this scattering problem. We find that the scattering cross section consists of two terms, one describing the classical phenomenon of elastic reflection and another one describing the quantum phenomenon of diffraction; the Aharonov--Bohm effect is manifested as a fringe shift in the diffraction pattern. Both the classical and the quantum phenomena are independent of the choice of a boundary condition at the vortex edge, providing that probability is conserved. We show that a propagation of charged particles can be controlled by altering the flux of a magnetic vortex placed on their way.

Yu. A. Sitenko; N. D. Vlasii
2013-12-05

51

Aharonov-Bohm Effect in Cyclotron and Synchrotron Radiations

  HEP - Theory (arXiv)

Summary: We study the impact of Aharonov-Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. With this aim in view, exact solutions of Klein-Gordon and Dirac equations are found in the magnetic-solenoid field. Using such solutions, we calculate exactly all the characteristics of one-photon spontaneous radiation both for spinless and spinning particle. Considering non-relativistic and relativistic approximations, we analyze cyclotron and synchrotron radiations in detail. Radiation peculiarities caused by the presence of the solenoid may be considered as a manifestation of Aharonov-Bohm effect in the radiation. In particular, it is shown that new spectral lines appear in the radiation spectrum. Due to angular distribution peculiarities of the radiation intensity, these lines can in principle be isolated from basic cyclotron and synchrotron radiation spectra

V. G. Bagrov; D. M. Gitman; A. Levin; V. B. Tlyachev
2000-11-06

52

Symmetry-protected many-body Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: It is known as a purely quantum effect that a magnetic flux affects the real physics of a particle, such as the energy spectrum, even if the flux does not interfere with the particle's path - the Aharonov-Bohm effect. Here we examine an Aharonov-Bohm effect on a many-body wavefunction. Specifically, we study this many-body effect on the gapless edge states of a bulk gapped phase protected by a global symmetry (such as $\\mathbb{Z}_{N}$) - the symmetry-protected topological (SPT) states. The many-body analogue of spectral shifts, the twisted wavefunction and the twisted boundary realization are identified in this SPT state. An explicit lattice construction of SPT edge states is derived, and a challenge of gauging its non-onsite symmetry is overcome. Agreement is found in the twisted spectrum between a numerical lattice calculation and a conformal field theory prediction.

Luiz H. Santos; Juven Wang
2014-08-19

53

Potential Effect: Aharonov-Bohm Effect of Simply Connected Region

  Quantum Physics (arXiv)

Summary: We study a generalization of Aharonov-Bohm effect, the potential effect. The discussion is focused on field-free effects in simply connected region, which obviously can not have any local field-flux. Among the published discussions about this kind of effects, it is generally agreed that this kind of effects does not exist due to gauge invariance. However, there are also opinions that this effect is a trivial variation of Aharonov-Bohm effect and therefore there is no need to check its existence. To my knowledge, it has never been tested. My first goal here is to supply enough theoretical reason to motivate the experimental test of this effect. I start with an intuitive derivation, then I introduce a wave-front theory as a theoretical consideration. Logically, the existence of potential effect implies the existence of the AB effect, but not vice versa. The purpose of this paper is to provide a physical connection in the opposite direction.

Jùn L{\\'?}u
1995-06-25

54

Nonassociativity, Dirac monopoles and Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm (AB) effect for the singular string associated with the Dirac monopole carrying an arbitrary magnetic charge is studied. It is shown that the emerging difficulties in explanation of the AB effect may be removed by introducing nonassociative path-dependent wave functions. This provides the absence of the AB effect for the Dirac string of magnetic monopole with an arbitrary magnetic charge.

Alexander I. Nesterov
2005-03-09

55

Radiative Corrections to the Aharonov-Bohm Scattering

  HEP - Theory (arXiv)

Summary: We consider the scattering of relativistic electrons from a thin magnetic flux tube and perturbatively calculate the order $\\alpha$, radiative correction, to the first order Born approximation. We show also that the second order Born amplitude vanishes, and obtain a finite inclusive cross section for the one-body scattering which incorporates soft photon bremsstrahlung effects. Moreover, we determine the radiatively corrected Aharonov-Bohm potential and, in particular, verify that an induced magnetic field is generated outside of the flux tube.

L. C. de Albuquerque; M. Gomes; A. J. da Silva
1999-06-22

56

Conditional Aharonov-Bohm Phases with Double Quantum Dots

  Quantum Physics (arXiv)

Summary: A quantum dot proposal for the implementation of topological quantum computation is presented. The coupling of the electron charge to an external magnetic field via the Aharonov-Bohm effect, combined with the control dynamics of a double dot, results in a two-qubit control phase gate. The physical mechanisms of the system are analysed in detail and the conditions for performing quantum computation resilient to control errors are outlined and found to be realisable with present technology.

Roberta Rodriquez; Jiannis K. Pachos
2004-05-13

57

On a generalized gravitational Aharonov-Bohm effect

  General Relativity & Quantum Cosmology (arXiv)

Summary: A massless spinor particle is considered in the background gravitational field due to a rotating body. In the weak field approximation it is shown that the solution of the Weyl equations depend on the angular momentum of the rotating body, which does not affect the curvature in this approximation. This result may be looked upon as a generalization of the gravitational Aharonov-Bohm effect.

Geusa de A. Marques; V. B. Bezerra
2003-02-07

58

Quantum anholonomies in time-dependent Aharonov-Bohm rings

  Nuclear Theory (arXiv)

Summary: Anholonomies in eigenstates are studied through time-dependent variations of a magnetic flux in an Aharonov-Bohm ring. The anholonomies in the eigenenergy and the expectation values of eigenstates are shown to persist beyond the adiabatic regime. The choice of the gauge of the magnetic flux is shown to be crucial to clarify the relationship of these anholonomies to the eigenspace anholonomy, which is described by a non-Abelian connection in the adiabatic limit.

Atushi Tanaka; Taksu Cheon
2010-08-12

59

Aharonov-Bohm Effect: a Quantum Variation and Classical Analogy

  Quantum Physics (arXiv)

Summary: In this work we consider a quantum variation of the usual Aharonov-Bohm effect with two solenoids sufficiently close one to the other so that (external) electron cannot propagate between two solenoids but only around both solenoids. Here magnetic field (or classical vector potential of the electromagnetic field) acting at quantum propagating (external) electron represents the quantum mechanical average value or statistical mixture. It is obtained by wave function of single (internal, quantum propagating within some solenoid wire) electron (or homogeneous ensemble of such (internal) electrons) representing a quantum superposition with two practically non-interfering terms. All this implies that phase difference and interference shape translation of the quantum propagating (external) electron represent the quantum mechanical average value or statistical mixture. On the other hand we consider a classical analogy and variation of the usual Aharonov-Bohm effect in which Aharonov-Bohm solenoid is used for the primary coil inside secondary large coil in the remarkable classical Faraday experiment of the electromagnetic induction.

Vladan Pankovic; Darko Kapor; Stevica Djurovic; Milan Pantic
2014-04-23

60

Aharonov-Bohm Oscillations in a Quasi-Ballistic 3D Topological-Insulator Nanowire , B. Dellabetta2

  Materials Science Websites

Summary: 1 Aharonov-Bohm Oscillations in a Quasi-Ballistic 3D Topological-Insulator Nanowire S. Cho1 , B of mechanically-exfoliated 3D TI nanowires which exhibit Aharonov-Bohm oscillations consistent with topological-momentum relation is clearly periodic in /0, leading to h/e Aharonov-Bohm (AB) oscillations12-14 . The topological

Gilbert, Matthew

61

Aharonov-Bohm Oscillations in the Presence of Strong Spin-Orbit Interactions Boris Grbic,1

  Materials Science Websites

Summary: the contributions from the second harmonic of AB oscillations and also find a beating in these h=2e oscillationsAharonov-Bohm Oscillations in the Presence of Strong Spin-Orbit Interactions Boris Grbic´,1 Renaud visible Aharonov-Bohm (AB) oscillations in a ring structure defined by local anodic oxidation on a p

Ihn, Thomas

62

Levinson's theorem and higher degree traces for Aharonov-Bohm operators

  Physics Websites

Summary: Levinson's theorem and higher degree traces for Aharonov-Bohm operators Johannes Kellendonk1 type theorems for the family of Aharonov-Bohm models from different perspectives. The first one precisely the various contributions to the left hand side of Levinson's theorem, namely those due

Paris-Sud XI, Université de

63

Discrete Gauge Symmetry and Aharonov-Bohm Radiation in String Theory

  HEP - Theory (arXiv)

Summary: We investigate cosmological constraints on phenomenological models with discrete gauge symmetries by discussing the radiation of standard model particles from Aharonov-Bohm strings. Using intersecting D-brane models in Type IIA string theory, we demonstrate that Aharonov-Bohm radiation, when combined with cosmological observations, imposes constraints on the compactification scales.

Yutaka Ookouchi
2013-12-11

64

Discrete Gauge Symmetry and Aharonov-Bohm Radiation in String Theory

  CERN Preprints

Summary: We investigate cosmological constraints on phenomenological models with discrete gauge symmetries by discussing the radiation of standard model particles from Aharonov-Bohm strings. Using intersecting D-brane models in Type IIA string theory, we demonstrate that Aharonov-Bohm radiation, when combined with cosmological observations, imposes constraints on the compactification scales.

Ookouchi, Yutaka
2013-01-01

65

Resolvent Convergence in Norm for Dirac Operator with Aharonov--Bohm Field

  Mathematics Websites

Summary: particles moving in the Aharonov--Bohm magnetic field in two dimensions. The field has #--like singularity is written as A 0# = #(-# 2 log |x|, # 1 log |x|), it has the point­like magnetic field #� A 0# = # 1 a 2Resolvent Convergence in Norm for Dirac Operator with Aharonov--Bohm Field Hideo Tamura Department


66

Realization of adiabatic Aharonov-Bohm scattering with neutrons

  Quantum Physics (arXiv)

Summary: The adiabatic Aharonov-Bohm (AB) effect is a manifestation of the Berry phase acquired when some slow variables take a planar spin around a loop. While the effect has been observed in molecular spectroscopy, direct measurement of the topological phase shift in a scattering experiment has been elusive in the past. Here, we demonstrate an adiabatic AB effect for neutrons that scatter on a long straight current-carrying wire. We propose an experiment to verify the effect and demonstrate its feasibility by explicit simulation of the dynamics of unpolarized very slow neutrons that scatter on the wire under realistic conditions.

Erik Sjöqvist; Martin Almquist; Ken Mattsson; Zeynep Nilhan Gürkan; Björn Hessmo
2015-03-08

67

Topology, Locality, and Aharonov-Bohm Effect with Neutrons

  HEP - Theory (arXiv)

Summary: Recent neutron interferometry experiments have been interpreted as demonstrating a new topological phenomenon similar in principle to the usual Aharonov-Bohm (AB) effect, but with the neutron's magnetic moment replacing the electron's charge. We show that the new phenomenon, called Scalar AB (SAB) effect, follows from an ordinary local interaction, contrary to the usual AB effect, and we argue that the SAB effect is not a topological effect by any useful definition. We find that SAB actually measures an apparently novel spin autocorrelation whose operator equations of motion contain the local torque in the magnetic field. We note that the same remarks apply to the Aharonov-Casher effect.

Murray Peshkin; H. J. Lipkin
1995-01-13

68

Strings and Aharonov-Bohm Effect in Abelian Higgs Model

  HEP - Phenomenology (arXiv)

Summary: We investigate numerically the properties of the Abrikosov-Nielsen-Olesen strings in 4D abelian Higgs model. The fractal dimension D_f of the vortex strings was found to be large in the Coulomb phase and it is close to 2 in the Higgs phase. We also show that the Wilson loop for non-integer charges is correlated with the linking number of the vortex string world sheets and the test particle world trajectory. We find that this topological (Aharonov-Bohm) interaction gives the main contribution to the Wilson loop quantum average for non-integer test charges in the vicinity of the Coulomb-Higgs phase transition.

M. N. Chernodub; M. I. Polikarpov; A. I. Veselov; M. A. Zubkov
1998-04-02

69

Strings and Aharonov-Bohm Effect in Abelian Higgs Model

  CERN Preprints

Summary: We investigate numerically the properties of the Abrikosov-Nielsen-Olesen strings in 4D abelian Higgs model. The fractal dimension D_f of the vortex strings was found to be large in the Coulomb phase and it is close to 2 in the Higgs phase. We also show that the Wilson loop for non-integer charges is correlated with the linking number of the vortex string world sheets and the test particle world trajectory. We find that this topological (Aharonov-Bohm) interaction gives the main contribution to the Wilson loop quantum average for non-integer test charges in the vicinity of the Coulomb-Higgs phase transition.

Chernodub, M N; Veselov, A I; Zubkov, M A
1998-01-01

70

Complemetarity of Phases in Aharonov-Bohm Solenoid Effect

  Quantum Physics (arXiv)

Summary: In the present Note it is suggested that there should be a certain complementarity of phases between Aharonov-Bohm (AB) solenoid phase calculation on one part of the system and a phase calculation about another part of the physical system. Assuming a unique value for the function of the total system, after a complete circulation of the electron around the solenoid, the sum of these two phase changes should vanish. Such assumption leads to a compatibility relation between our previous calculations for the AB solenoid phase effect and that of the original calculation by AB.

Y. Ben-Aryeh
2011-12-21

71

Combined Electric and Magnetic Aharonov-Bohm Effects

  Quantum Physics (arXiv)

Summary: It is well-known that the electric and magnetic Aharonov-Bohm effects may be formally described on equal footing using the four-vector potential in a relativistic framework. We propose an illustrative manifestation of both effects in a single configuration, in which the specific path of the charged particle determines the weight of the electric and magnetic acquired relative phases. The phases can be distinctively obtained in the Coulomb gauge. The scheme manifests the pedagogical lesson that though each of the relative phases is gauge-dependent their sum is gauge-invariant.

Samuel Marcovitch; Yakir Aharonov; Tirza Kaufferr; Benni Reznik
2007-09-11

72

A macroscopic test of the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm (AB) effect is a purely quantum mechanical effect. The original (classified as Type-I) AB-phase shift exists in experimental conditions where the electromagnetic fields and forces are zero. It is the absence of forces that makes the AB-effect entirely quantum mechanical. Although the AB-phase shift has been demonstrated unambiguously, the absence of forces in Type-I AB-effects has never been shown. Here, we report the observation of the absence of time delays associated with forces of the magnitude needed to explain the AB-phase shift for a macroscopic system.

Adam Caprez; Brett Barwick; Herman Batelaan
2007-08-17

73

Perturbation Theory and the Aharonov-Bohm Effect

  HEP - Theory (arXiv)

Summary: The perturbation theory expansion of the Aharonov-Bohm scattering amplitude has previously been studied in the context of quantum mechanics for spin zero and spin-1/2 particles as well in Galilean covariant field theory. This problem is reconsidered in the framework of the model in which the flux line is considered to have a finite radius which is shrunk to zero at the end of the calculation. General agreement with earlier results is obtained but with the advantage of a treatment which unifies all the various subcases.

C. R. Hagen
1995-03-06

74

Gravitational Aharonov-Bohm effect and gravitational lensing

  General Relativity & Quantum Cosmology (arXiv)

Summary: Considering the spacetime around a rotating massif body it is seen that the time of flight of a light ray is different whether it travels on one side of the source or on the other. The difference is proportional to the angular momentum of the body. In the case that a compact rapidly rotating object is the source of a gravitational lensing effect, the contribution coming from the above mentioned gravitational Aharonov-Bohm effect should be added to the other causes of phase difference between light rays coming from different images of the same object.

A. Tartaglia
2000-03-08

75

QED processes beyond the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: We consider QED - processes in the presence of an infinitely thin and infinitely long straight string with a magnetic flux inside it. The bremsstrahlung from an electron passing by the magnetic string and the electron-positron pair production by a single photon are reviewed. Based on the exact electron and positron solutions of the Dirac equation in the external Aharonov-Bohm potential we present matrix elements for these processes. The dependence of the resulting cross sections on energies, directions and polarizations of the involved particles is discussed for low energies.

J. Audretsch; V. D. Skarzhinsky
1997-09-14

76

The gravitational analog of the Aharonov-Bohm electric effect

  Quantum Physics (arXiv)

Summary: The electric Aharonov-Bohm effect is a special case of the general Ab effect. However, when inserting a gravitational potential in the place of the time dependent potential, a different understanding of the phase shift could be gained. The usual topological phase is replaced by a phase with origin in the red shift of the particle at one of the paths taken relative to the other path. In this case, the change in the geometrical measure is the source of the phase shift, which therefore has a local interpretation along with the non-local topological explanation.

Doron M. Ludwin
2010-12-27

77

The incident wave in Aharonov-Bohm scattering wavefunction

  HEP - Theory (arXiv)

Summary: It is shown that only the infinite angular momentum quantum states contribute to the incident wave in Aharonov-Bohm (AB) scattering. This result is clearly shown by recalculating the AB calculation with arbitrary decomposition of summation over the angular momentum quantum numbers in wave function. It is motivated from the fact that the pole contribution in the integral representation used by Jackiw is given by only the infinite angular momentum states, in which the closed contour integration involving this pole gives just the incident wave.

Sahng-Kyoon Yoo; D. K. Park
1997-07-02

78

Remarks on magnetic and electric Aharonov-Bohm effects

  Mathematical Physics (arXiv)

Summary: We give a direct proof of the magnetic Aharonov-Bohm effects without using the scattering theory and the theory of inverse boundary value problems. This proof can serve as a framework for a physical experiment to confirm the magnetic AB effect. We prove also the electric AB effect and we suggest a physical experiment to demonstrate the electric AB effect. In addition, we consider a combined electric and magnetic AB effect and we propose a new inverse problem for the time-dependent Schr\\"odinger equations. Finally we study the gravitational AB effect.

Gregory Eskin
2011-09-17

79

Two-Color QCD and Aharonov-Bohm Fluxes

  HEP - Lattice (arXiv)

Summary: We investigate the effects of several Abelian Aharonov-Bohm fluxes $\\phi$ on the Euclidean Dirac spectrum of light quarks in QCD with two colors. A quantitative change in the quark return probability is caused by the fluxes, resulting into a change of the spectral correlations. These changes are controlled by a universal function of $\\sigma_L \\phi^2$ where $\\sigma_L$ is the pertinent Ohmic conductance. The quark return probability is sensitive to Abelian flux-disorder but not to $Z_2$ flux-disorder in the ergodic and diffusive regime, and may be used as a probe for the nature of the confining fields in the QCD vacuum.

Romuald A. Janik; Maciej A. Nowak; Gabor Papp; Ismail Zahed
1998-07-26

80

On the Locality Principle Keeping in Aharonov-Bohm Effect

  Physics (arXiv)

Summary: The locality principle fulfillment in the Aharonov-Bohm (AB) effect is analyzed from the point of view of a self-sufficient potential formalism based on so-called gradient hypothesis in electrodynamics. The "magnetic" kind of AB effect is examined (as the quantum charged particle moves to an infinitely long solenoid with a permanent current), and no locality principle violation recognized if the gradient hypothesis is used. A conclusion is made that AB effect is no longer a physical and electrodynamic "paradox".

Alexander Gritsunov; Natalie Masolova
2013-07-01

81

Aharonov-Bohm-Coulomb Problem in Graphene Ring

  Quantum Physics (arXiv)

Summary: We study the Aharonov-Bohm-Coulomb problem in a graphene ring. We investigate, in particular, the effects of a Coulomb type potential of the form $\\xi/r$ on the energy spectrum of Dirac electrons in the graphene ring in two different ways: one for the scalar coupling and the other for the vector coupling. It is found that, since the potential in the scalar coupling breaks the time-reversal symmetry between the two valleys as well as the effective time-reversal symmetry in a single valley, the energy spectrum of one valley is separated from that of the other valley, demonstrating a valley polarization. In the vector coupling, however, the potential does not break either of the two symmetries and its effect appears only as an additive constant to the spectrum of Aharonov-Bohm potential. The corresponding persistent currents, the observable quantities of the symmetry-breaking energy spectra, are shown to be asymmetric about zero magnetic flux in the scalar coupling, while symmetric in the vector coupling.

Eylee Jung; Mi-Ra Hwang; ChangSoo Park; DaeKil Park
2012-01-14

82

Aharonov-Bohm and Coulomb Scattering Near the Forward Direction

  HEP - Theory (arXiv)

Summary: The exact wave functions that describe scattering of a charged particle by a confined magnetic field (Aharonov-Bohm effect) and by a Coulomb field are analyzed. It is well known that the usual procedure of finding asymptotic forms of these functions which admit a separation into a superposition of an incident plane wave and a circular or spherical scattered wave is problematic near the forward direction. It thus appears to be impossible to express the conservation of probability by means of an optical theorem of the usual kind. Both the total cross section and the forward scattering amplitude appear to be infinite. To address these difficulties we find a new representation for the asymptotic form of the Aharonov-Bohm wave function that is valid for all angles. Rather than try to define a cross section at forward angles, however, we work instead with the probability current and find that it is quite well behaved. The same is true for Coulomb scattering. We trace the usual difficulties to a nonuniformity of limits.

Charles M. Sommerfield; Hisakazu Minakata
2000-07-07

83

Two-particle Aharonov-Bohm effect and Entanglement in the electronic Hanbury Brown Twiss setup

  Quantum Physics (arXiv)

Summary: We analyze a Hanbury Brown Twiss geometry in which particles are injected from two independent sources into a mesoscopic electrical conductor. The set-up has the property that all partial waves end in different reservoirs without generating any single particle interference. There is no single particle Aharonov-Bohm effect. However, exchange effects lead to two-particle Aharonov-Bohm oscillations in current correlations. We demonstrate that the two-particle Aharonov-Bohm effect is connected to orbital entanglement which can be used for violation of a Bell Inequality.

P. Samuelsson; E. V. Sukhorukov; M. Buttiker
2003-09-24

84

Generalised boundary conditions for the Aharonov-Bohm effect combined with a homogeneous magnetic field

  Mathematical Physics (arXiv)

Summary: The most general admissible boundary conditions are derived for an idealised Aharonov-Bohm flux intersecting the plane at the origin on the background of a homogeneous magnetic field. A standard technique based on self-adjoint extensions yields a four-parameter family of boundary conditions; other two parameters of the model are the Aharonov-Bohm flux and the homogeneous magnetic field. The generalised boundary conditions may be regarded as a combination of the Aharonov-Bohm effect with a point interaction. Spectral properties of the derived Hamiltonians are studied in detail.

Pavel Exner; Pavel Stovicek; Petr Vytras
2001-11-08

85

Paradoxes of the Aharonov-Bohm and the Aharonov-Casher effects

  Quantum Physics (arXiv)

Summary: For a believer in locality of Nature, the Aharonov-Bohm effect and the Aharonov-Casher effect are paradoxes. I discuss these and other Aharonov's paradoxes and propose a local explanation of these effects. If the solenoid in the Aharonov-Bohm effect is treated quantum mechanically, the effect can be explained via local interaction between the field of the electron and the solenoid. I argue that the core of the Aharonov-Bohm and the Aharonov-Casher effects is that of quantum entanglement: the quantum wave function describes all systems together.

Lev Vaidman
2013-01-25

86

The bound state Aharonov-Bohm effect around a cosmic string revisited

  General Relativity & Quantum Cosmology (arXiv)

Summary: In this article we observe that the self-adjoint extension of the Hamiltonian of a particle moving around a shielded cosmic string gives rise to a gravitational analogue of the bound state Aharonov-Bohm effect.

C. Filgueiras; Fernando Moraes
2005-09-26

87

Gauge equivalence classes of flat connections in the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: In this note we present a simplified derivation of the fact that the moduli space of flat connections in the abelian Aharonov-Bohm effect is isomorphic to the circle. The length of this circle is the electric charge.

M. A. Aguilar; J. M. Isidro; M. Socolovsky
2003-05-23

88

Propagator for spinless and spin-1/2 Aharonov-Bohm-Coulomb systems

  HEP - Theory (arXiv)

Summary: The propagator of the spinless Aharonov-Bohm-Coulomb system is derived by following the Duru-Kleinert method. We use this propagator to explore the spin-1/2 Aharonov-Bohm-Coulomb system which contains a point interaction as a Zeeman term. Incorporation of the self-adjoint extension method into the Green's function formalism properly allows us to derive the finite propagator of the spin-1/2 Aharonov-Bohm-Coulomb system. As a by-product, the relation between the self-adjoint extension parameter and the bare coupling constant is obtained. Bound-state energy spectra of both spinless and spin-1/2 Aharonov-Bohm-Coulomb systems are examined.

D. K. Park; Sahng-Kyoon Yoo
1997-11-01

89

Whirling Waves and the Aharonov-Bohm Effect for Relativistic Spinning Particles

  HEP - Theory (arXiv)

Summary: The formulation of Berry for the Aharonov-Bohm effect is generalized to the relativistic regime. Then, the problem of finding the self-adjoint extensions of the (2+1)-dimensional Dirac Hamiltonian, in an Aharonov-Bohm background potential, is solved in a novel way. The same treatment also solves the problem of finding the self-adjoint extensions of the Dirac Hamiltonian in a background Aharonov-Casher.

H. O. Girotti; F. Fonseca Romero
1996-12-05

90

Gravito-electromagnetic Aharonov-Bohm effect: some rotation effects revised

  General Relativity & Quantum Cosmology (arXiv)

Summary: By means of the description of the standard relative dynamics in terms of gravito-electromagnetic fields, in the context of natural splitting, we formally introduce the gravito-magnetic Aharonov-Bohm effect. Then, we interpret the Sagnac effect as a gravito-magnetic Aharonov-Bohm effect and we exploit this formalism for studying the General Relativistic corrections to the Sagnac effect in stationary and axially symmetric geometries.

Matteo Luca Ruggiero
2010-07-22

91

Photon mass and quantum effects of the Aharonov-Bohm type

  Quantum Physics (arXiv)

Summary: The magnetic field due to the photon rest mass $m_{ph}$ modifies the standard results of the Aharonov-Bohm effect for electrons, and of other recent quantum effects. For the effect involving a coherent superposition of beams of particles with opposite electromagnetic properties, by means of a table-top experiment, the limit $m_{ph}x10^{-51}g$ is achievable, improving by 6 orders of magnitude that derived by Boulware and Deser for the Aharonov-Bohm effect.

G. Spavieri; M. Rodriguez
2007-05-08

92

Radiation of Supersymmetric Particles from Aharonov-Bohm R-string

  HEP - Phenomenology (arXiv)

Summary: We study radiation of supersymmetric particles from an Aharonov-Bohm string associated with a discrete R-symmetry. Radiation of the lightest supersymmetric particle, when combined with the observed dark matter density, imposes constraints on the string tension or the freeze-out temperature of the particle. We also calculate the amplitude for Aharonov-Bohm radiation of massive spin $3/2$ particles.

Yutaka Ookouchi; Takahiro Yonemoto
2015-02-08

93

The Aharonov-Casher and scalar Aharonov-Bohm topological effects

  Quantum Physics (arXiv)

Summary: We reexamine the topological and nonlocal natures of the Aharonov-Casher and scalar Aharonov-Bohm phase effects. The underlying U(1) gauge structure is exhibited explicitly. And the conditions for developing topological Aharonov-Casher and scalar Aharonov-Bohm phases are clarified. We analyse the arguments of M. Peshkin and H. J. Lipkin (Phys. Rev. Lett. 74, 2847(1995)) in detail and show that they are based on the wrong Hamiltonian which yields their conclusion incorrect.

Sayipjamal Dulat; Kai Ma
2012-03-23

94

Aharonov-Bohm photonic cages in waveguide and coupled resonator lattices by synthetic magnetic fields

  CERN Preprints

Summary: We suggest a method for trapping photons in quasi one-dimensional waveguide or coupled-resonator lattices, which is based on an optical analogue of the Aharonov-Bohm cages for charged particles. Light trapping results from a destructive interference of Aharonov-Bohm type induced by a synthetic magnetic field, which is realized by periodic modulation of the waveguide/resonator propagation constants/resonances.

Longhi, Stefano
2014-01-01

95

Aharonov-Bohm photonic cages in waveguide and coupled resonator lattices by synthetic magnetic fields

  Quantum Physics (arXiv)

Summary: We suggest a method for trapping photons in quasi one-dimensional waveguide or coupled-resonator lattices, which is based on an optical analogue of the Aharonov-Bohm cages for charged particles. Light trapping results from a destructive interference of Aharonov-Bohm type induced by a synthetic magnetic field, which is realized by periodic modulation of the waveguide/resonator propagation constants/resonances.

Stefano Longhi
2014-09-27

96

Multiple solutions to a nonlinear Schrodinger equation with Aharonov-Bohm magnetic poten-

  Environmental Sciences and Ecology Websites

Summary: Multiple solutions to a nonlinear Schr¨odinger equation with Aharonov-Bohm magnetic poten- tial M´onica Clapp and Andrzej Szulkin Abstract. We consider the magnetic nonlinear Schr¨odinger equations (-i + sA)2}, s R, and A : R3 R3 is the Aharonov-Bohm magnetic potential A(x1, x2, x3) := 1 x2 1 + x2 2 (-x2, x1, 0

Szulkin, Andrzej

97

Radiation of Supersymmetric Particles from Aharonov-Bohm R-string

  CERN Preprints

Summary: We study radiation of supersymmetric particles from an Aharonov-Bohm string associated with a discrete R-symmetry. Radiation of the lightest supersymmetric particle, when combined with the observed dark matter density, imposes constraints on the string tension or the freeze-out temperature of the particle. We also calculate the amplitude for Aharonov-Bohm radiation of massive spin $3/2$ particles.

Ookouchi, Yutaka
2014-01-01

98

An Aharonov-Bohm interferometer for determining Bloch band topology

  Quantum Physics (arXiv)

Summary: The geometric structure of an energy band in a solid is fundamental for a wide range of many-body phenomena in condensed matter and is uniquely characterized by the distribution of Berry curvature over the Brillouin zone. In analogy to an Aharonov-Bohm interferometer that measures the magnetic flux penetrating a given area in real space, we realize an atomic interferometer to measure Berry flux in momentum space. We demonstrate the interferometer for a graphene-type hexagonal lattice, where it has allowed us to directly detect the singular $\\pi$ Berry flux localized at each Dirac point. We show that the interferometer enables one to determine the distribution of Berry curvature with high momentum resolution. Our work forms the basis for a general framework to fully characterize topological band structures and can also facilitate holonomic quantum computing through controlled exploitation of the geometry of Hilbert space.

Lucia Duca; Tracy Li; Martin Reitter; Immanuel Bloch; Monika Schleier-Smith; Ulrich Schneider
2014-07-21

99

Noncommutative analogue Aharonov-Bohm effect and superresonance

  CERN Preprints

Summary: We consider the idea of modeling a rotating acoustic black hole by an idealized draining bathtub vortex which is a planar circulating flow phenomenon with a sink at the origin. We find the acoustic metric for this phenomenon from a noncommutative Abelian Higgs model. As such the acoustic metric not only describes a rotating acoustic black hole but also inherits the noncommutative characteristic of the spacetime. We address the issues of superresonance and analogue Aharonov-Bohm (AB) effect in this background. We mainly show that the scattering of planar waves by a draining bathtub vortex leads to a modified AB effect and due to spacetime noncommutativity, the phase shift persists even in the limit where the parameters associated with the circulation and draining vanish. Finally, we also find that the analogue AB effect and superresonance are competing phenomena at a noncommutative spacetime.

Anacleto, M A; Passos, E
2012-01-01

100

Broken unitarity and phase measurements in Aharonov-Bohm interferometers

  Condensed Matter (arXiv)

Summary: Aharonov-Bohm mesoscopic solid-state interferometers yield a conductance which contains a term $\\cos(\\phi+\\beta)$, where $\\phi$ relates to the magnetic flux. Experiments with a quantum dot on one of the interfering paths aim to relate $\\beta$ to the dot's intrinsic Friedel transmission phase, $\\alpha_1$. For closed systems, which conserve the electron current (unitarity), the Onsager relation requires that $\\beta=0$. For open systems, we show that $\\beta$ depends in general on the details of the broken unitarity. Although it gives information on the resonances of the dot, $\\beta$ is generally not equal to $\\alpha_1$. A direct relation between $\\beta$ and $\\alpha_1$ requires specific ways of opening the system, which are discussed.

O. Entin-Wohlman; A. Aharony; Y. Imry; Y. Levinson; A. Schiller
2002-02-22

101

Noncommutative Quantum Hall Effect and Aharonov-Bohm Effect

  HEP - Theory (arXiv)

Summary: We study a system of electrons moving on a noncommutative plane in the presence of an external magnetic field which is perpendicular to this plane. For generality we assume that the coordinates and the momenta are both noncommutative. We make a transformation from the noncommutative coordinates to a set of commuting coordinates and then we write the Hamiltonian for this system. The energy spectrum and the expectation value of the current can then be calculated and the Hall conductivity can be extracted. We use the same method to calculate the phase shift for the Aharonov-Bohm effect. Precession measurements could allow strong upper limits to be imposed on the noncommutativity coordinate and momentum parameters $\\Theta$ and $\\Xi$.

B. Harms; O. Micu
2007-01-07

102

Aharonov-Bohm quantum rings in high-Q microcavities

  Quantum Physics (arXiv)

Summary: A single-mode microcavity with an embedded Aharonov-Bohm quantum ring, which is pierced by a magnetic flux and subjected to a lateral electric field, is studied theoretically. It is shown that external electric and magnetic fields provide additional means of control of the emission spectrum of the system. In particular, when the magnetic flux through the quantum ring is equal to a half-integer number of the magnetic flux quantum, a small change in the lateral electric field allows tuning of the energy levels of the quantum ring into resonance with the microcavity mode providing an efficient way to control the quantum ring-microcavity coupling strength. Emission spectra of the system are calculated for several combinations of the applied magnetic and electric fields.

A. M. Alexeev; I. A. Shelykh; M. E. Portnoi
2013-02-08

103

Scattering on two Aharonov-Bohm vortices with opposite fluxes

  Mathematical Physics (arXiv)

Summary: The scattering of an incident plane wave on two Aharonov-Bohm vortices with opposite fluxes is considered in detail. The presence of the vortices imposes non-trivial boundary conditions for the partial waves on a cut joining the two vortices. These conditions result in an infinite system of equations for scattering amplitudes between incoming and outgoing partial waves, which can be solved numerically. The main focus of the paper is the analytic determination of the scattering amplitude in two limits, the small flux limit and the limit of small vortex separation. In the latter limit the dominant contribution comes from the S-wave amplitude. Calculating it, however, still requires solving an infinite system of equations, which is achieved by the Riemann-Hilbert method. The results agree well with the numerical calculations.

E Bogomolny; S Mashkevich; S Ouvry
2010-03-01

104

Noncommutative analogue Aharonov-Bohm effect and superresonance

  HEP - Theory (arXiv)

Summary: We consider the idea of modeling a rotating acoustic black hole by an idealized draining bathtub vortex which is a planar circulating flow phenomenon with a sink at the origin. We find the acoustic metric for this phenomenon from a noncommutative Abelian Higgs model. As such the acoustic metric not only describes a rotating acoustic black hole but also inherits the noncommutative characteristic of the spacetime. We address the issues of superresonance and analogue Aharonov-Bohm (AB) effect in this background. We mainly show that the scattering of planar waves by a draining bathtub vortex leads to a modified AB effect and due to spacetime noncommutativity, the phase shift persists even in the limit where the parameters associated with the circulation and draining vanish. Finally, we also find that the analogue AB effect and superresonance are competing phenomena at a noncommutative spacetime.

M. A. Anacleto; F. A. Brito; E. Passos
2013-05-27

105

The scalar complex potential and the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm effect is traditionally attributed to the effect of the electromagnetic 4-potential $A$, even in regions where both the electric field $\\mathbf{E}$ and the magnetic field $\\mathbf{B}$ are zero. The AB effect reveals that multiple-valued functions play a crucial role in the description of an electromagnetic field. We argue that the quantity measured by AB experiments is a difference in values of a multiple-valued complex function, which we call a complex potential or {pre-potential. We show that any electromagnetic field can be described by this pre-potential, and give an explicit expression for the electromagnetic field tensor through this potential. The pre-potential is a modification of the two scalar potential functions.

Y. Friedman; V. Ostapenko
2010-02-01

106

Nonlinear Aharonov-Bohm scattering by optical vortices

  Condensed Matter (arXiv)

Summary: We study linear and nonlinear wave scattering by an optical vortex in a self-defocusing nonlinear Kerr medium. In the linear case, we find a splitting of a plane-wave front at the vortex proportional to its circulation, similar to what occurs in the scattered wave of electrons for the Aharonov-Bohm effect. For larger wave amplitudes, we study analytically and numerically the scattering of a dark-soliton stripe (a nonlinear analog of a small-amplitude wavepacket) by a vortex and observe a significant asymmetry of the scattered wave. Subsequently, a wavefront splitting of the scattered wave develops into transverse modulational instability, ``unzipping'' the stripe into trains of vortices with opposite charges.

Dragomir Neshev; Alexander Nepomnyashchy; Yuri S. Kivshar
2001-07-03

107

Non-Abelian Vortices with an Aharonov-Bohm Effect

  HEP - Theory (arXiv)

Summary: The interplay of gauge dynamics and flavor symmetries often leads to remarkably subtle phenomena in the presence of soliton configurations. Non-Abelian vortices -- vortex solutions with continuous internal orientational moduli -- provide an example. Here we study the effect of weakly gauging a U(1)_R subgroup of the flavor symmetry on such BPS vortex solutions. Our prototypical setting consists of an SU(2) x U(1) gauge theory with N_f=2 sets of fundamental scalars that break the gauge symmetry to an "electromagnetic" U(1). The weak U(1)_R gauging converts the well-known CP1 orientation modulus |B| of the non-Abelian vortex into a parameter characterizing the strength of the magnetic field that is responsible for the Aharonov-Bohm effect. As the phase of B remains a genuine zero mode while the electromagnetic gauge symmetry is Higgsed in the interior of the vortex, these solutions are superconducting strings.

Jarah Evslin; Kenichi Konishi; Muneto Nitta; Keisuke Ohashi; Walter Vinci
2013-12-23

108

Universal Formula for the Expectation Value of the Radial Operator under the Aharonov-Bohm Flux and the Coulomb Field

  Quantum Physics (arXiv)

Summary: A useful and universal formula for the expectation value of the radial operator in the presence of the Aharonov-Bohm flux and the Coulomb Field is established. We find that the expectation value $< r^{\\lambda}>$ $(-\\infty \\leq \\lambda \\leq \\infty)$ is greatly affected due to the non-local effect of the magnetic flux although the Aharonov-Bohm flux does not have any dynamical significance in classical mechanics. In particular, the quantum fluctuation increases in the presence of the magnetic flux due to the Aharonov-Bohm effect. In addition, the Virial theory in quantum mechanics is also constructed for the spherically symmetric system under the Aharonov-Bohm effect.

W. F. Kao; Y. M. Kao; D. H. Lin
2002-10-14

109

Aharonov-Bohm Effect and High-Velocity Estimates of Solutions to the Schrödinger Equation

  Mathematical Physics (arXiv)

Summary: The Aharonov-Bohm effect is a fundamental and controversial issue in physics. At stake are what are the fundamental electromagnetic quantities in quantum physics, if magnetic fields can act at a distance on charged particles and if the magnetic potentials have a real physical significance. From the experimental side the issues were settled by the remarkable experiments of Tonomura et al. in 1982 and 1986 with toroidal magnets that gave a strong experimental evidence of the physical existence of the Aharonov-Bohm effect, and by the recent experiment of Caprez et al. in 2007 that shows that the results of these experiments can not be explained by a force. The Aharonov-Bohm Ansatz of 1959 predicts the results of the experiments of Tonomura et al. and of Caprez et al. In 2009 we gave the first rigorous proof that the Aharonov-Bohm Ansatz is a good approximation to the exact solution for toroidal magnets under the conditions of the experiments of Tonomura et al.. In this paper we prove that our results do not depend on the particular geometry of the magnets and on the velocities of the incoming electrons used on the experiments, and on the gaussian shape of the wave packets used to obtain our quantitative error bound. We consider a general class of magnets that are a finite union of handle bodies. We formulate the Aharonov-bohm Ansatz that is appropriate to this general case and we prove that the exact solution to the Schroedinger equation is given by the Aharonov-Bohm Ansatz up to an error bound in norm that is uniform in time and that decays as a constant divided by $v^\\rho, 0 < \\rho <1$, with $v$ the velocity. The results of Tonomura et al., of Caprez et al., our previous results and the results of this paper give a firm experimental and theoretical basis to the existence of the Aharonov-Bohm effect and to its quantum nature.

Miguel Ballesteros; Ricardo Weder
2010-04-04

110

Carbon nanotubes in confined magneticCarbon nanotubes in confined magnetic fields: AharonovBohm oscillations andfields: AharonovBohm oscillations and

  Physics Websites

Summary: ;The AB effect in carbon nano-tubes (CNTs) A. Bachtold et al., Nature 397, 673 (1999) S. Zaric et alCarbon nanotubes in confined magneticCarbon nanotubes in confined magnetic fields: Aharonov;OutlineOutline Aharonov-Bohm oscillations in Carbon nanotubes Curvature effects Persistent currents #12

Marini, Andrea

111

Free and bound spin-polarized fermions in the fields of Aharonov--Bohm kind

  Quantum Physics (arXiv)

Summary: The scattering of electrons by an Aharonov--Bohm field is considered from the viewpoint of quantum-mechanical problem of constructing a self-adjoint Hamiltonian for the Pauli equation. The correct domain for the self-adjoint Hamiltonian, which takes into account explicitly the electron spin is found. A one-parameter self-adjoint extension of the Hamiltonian for spin-polarized electrons in the Aharonov--Bohm field is selected. The correct domain of the self-adjoint Hamiltonian can contain regular and singular (at the point ${\\bf r}=0$) square-integrable functions on the half-line with measure $rdr$. We argue that the physical reason of the existence of singular functions is the additional attractive potential, which appear due to the interaction between the spin magnetic moment of fermion and Aharonov--Bohm magnetic field. The scattering amplitude and cross section are obtained for spin-polarized electrons scattered by the Aharonov--Bohm field. It is shown that in some range of the extension parameter there appears a bound state. Since the Hamiltonian of the nonrelativistic Dirac--Pauli equation for a massive neutral fermion with the anomalous magnetic moment (AMM) in the electric field of a linear charge aligned perpendicularly to the fermion motion has the form of the Hamiltonian for the Pauli equation in the Aharonov--Bohm flux tube, we also calculate the scattering amplitude and cross section for the neutral fermion.

V. R. Khalilov; I. V. Mamsurov; Lee Ki Eun
2010-02-15

112

Physica E 40 (2008) 12731275 AharonovBohm oscillations in p-type GaAs quantum rings

  Materials Science Websites

Summary: of 160 nm. Beside the h=e oscillations, we resolve the contributions from higher harmonics of the ABPhysica E 40 (2008) 1273­1275 Aharonov­Bohm oscillations in p-type GaAs quantum rings Boris Grbic oxidation lithography. Highly visible Aharonov­Bohm (AB) oscillations are measured in both rings

Ihn, Thomas
2008-01-01

113

Electron Vortex Beams in a Magnetic Field: A New Twist on Landau Levels and Aharonov-Bohm States

  Materials Science Websites

Summary: Electron Vortex Beams in a Magnetic Field: A New Twist on Landau Levels and Aharonov-Bohm States and the Landau case of a uniform magnetic field. While stationary Aharonov-Bohm modes represent Bessel beams with flux- and vortex-dependent probability distributions, stationary Landau states manifest themselves

Nori, Franco

114

Aharonov-Bohm-Coulomb Problem in Graphene Ring

  CERN Preprints

Summary: We study the Aharonov-Bohm-Coulomb problem in a graphene ring. We especially investigate the effects of a Coulomb potential on the energy spectrum of Dirac electrons in the graphene ring in two different ways: one for the scalar coupling and the other for the vector coupling to the 2D Dirac equation. It is found that, since the Coulomb potential in the scalar coupling breaks the time reversal symmetry between the two valleys as well as the effective time reversal symmetry in a single valley, the energy spectrum of one valley is separated from that of the other valley, representing the valley polarization. In the vector coupling, however, the Coulomb potential does not break either of the two symmetries and its effect appears only as an additive constant to the spectrum of AB potential. The corresponding persistent currents are shown to be asymmetric about zero magnetic flux in the scalar coupling, while symmetric in the vector coupling. Our results can be used to determine experimently the ambiguity arising i...

Jung, Eylee; Park, ChangSoo; Kim, Kwang S; Park, DaeKil
2011-01-01

115

Aharonov-Bohm interferences from local deformations in graphene

  Quantum Physics (arXiv)

Summary: One of the most interesting aspects of graphene is the tied relation between structural and electronic properties. The observation of ripples in the graphene samples both free standing and on a substrate has given rise to a very active investigation around the membrane-like properties of graphene and the origin of the ripples remains as one of the most interesting open problems in the system. The interplay of structural and electronic properties is successfully described by the modelling of curvature and elastic deformations by fictitious gauge fields that have become an ex- perimental reality after the suggestion that Landau levels can form associated to strain in graphene and the subsequent experimental confirmation. Here we propose a device to detect microstresses in graphene based on a scanning-tunneling-microscopy setup able to measure Aharonov-Bohm inter- ferences at the nanometer scale. The interferences to be observed in the local density of states are created by the fictitious magnetic field associated to elastic deformations of the sample.

Fernando de Juan; Alberto Cortijo; María A. H. Vozmediano; Andrés Cano
2011-05-04

116

Force and impulse from an Aharonov-Bohm flux line

  Mathematical Physics (arXiv)

Summary: We calculate the force and impulse operators for a charged particle in the field of an Aharonov-Bohm flux line. The force operator is formally the Lorentz force, with the magnetic field operator modified to include quantum corrections due to anomolous commutation relations. Expectation values for stationary states are calculated. Nonstationary states are treated by integrating the force operator in time to obtain the impulse operator. Expectation values of the impulse are calculated for slow wavepackets (which spread faster than they move) and for fast wavepackets (which spread only negligibly before their closest approach to the flux line). We give two derivations of the force and impulse operators, the first a simple derivation based on formal arguments, and the second a rigorous calculation of wavepacket expectation values. We also show that the same expressions for the force and impulse are obtained if the flux line is enclosed in an impenetrable cylinder,or distributed uniformly over a flux cylinder, in the limit that the radius of the cylinder goes to zero.

J. P. Keating; J. M. Robbins
2002-12-06

117

Aharonov--Bohm effect, electrodynamics postulates, and Lorentz condition

  Quantum Physics (arXiv)

Summary: The problem of the relation between the Ahronov-Bohm effect and traditional postulates of electrodynamics, which claim that only electric and magnetic fields are observable, is resolved by denial of the statement about validity of the Maxwell equations for microscopic fields. We proceed from the idea that the Maxwell equations, as the generalization of experimental data, are valid only for averaged values. We show that microscopic electrodynamics should be based on postulation of the d'Alembert equations for four-vector of the electromagnetic field potential. The Lorentz condition is valid only for the averages and provides the implementation of the Maxwell equations for averages. This concept eliminates the problem of electromagnetic field quantization and provides the correctness of all known results of quantum electrodynamics. Therefore, the "virtuality" of the longitudinal and scalar photons has a formal mathematical character, conditioned by the Maxwell equations for averaged fields. The longitudinal and scalar photons provide not only the Coulomb interaction of charged particles, but also allow the electrical Aharonov-Bohm effect.

V. B. Bobrov; S. A. Trigger; G. J. F. van Heijst; P. P. J. M. Schram
2013-06-28

118

Aharonov-Bohm effect, local field interaction, and Lorentz invariance

  Quantum Physics (arXiv)

Summary: Aharonov-Bohm (AB) effect [1,2], known as a milestone in our understanding of electromagnetic interactions, describes a quantum interference of a charged particle moving under the influence of a potential. In sharp contrast with classical theory of electrodynamics, AB effect qualifies potential as a physical reality, rather than as a mere mathematical tool, because the interference is affected by a potential even when a charged particle moves in a field-free region. Aharonov-Casher (AC) effect [3], dual to the AB phenomenon, shows a phase shift of a fluxon moving around a charge (in two-dimensional case). It has been shown that AC effect is also free of force [4,5], but standard view draws a clear distinction between the two phenomena in that the fluxon moves under a nonvanishing field generated by the charge in the case of AC effect [6]. Despite the fact that the observable phenomena depend only on the relative motion of a charge and a fluxon, a unified picture, fully consistent with the principle of relativity, is lacking. Here, we provide a unified theory which resolves the question of relativity, based on a Lorentz-invariant field-interaction between a charge and a localized flux. The AB effect can be understood in this fully relativistic viewpoint. The AB phase shift is derived from the Lorentz-covariant interaction Lagrangian, and the force-free nature of the effect is also confirmed.

Kicheon Kang
2015-02-03

119

Loop Quantum Gravity a la Aharonov-Bohm

  General Relativity & Quantum Cosmology (arXiv)

Summary: The state space of Loop Quantum Gravity admits a decomposition into orthogonal subspaces associated to diffeomorphism equivalence classes of spin-network graphs. In this paper I investigate the possibility of obtaining this state space from the quantization of a topological field theory with many degrees of freedom. The starting point is a 3-manifold with a network of defect-lines. A locally-flat connection on this manifold can have non-trivial holonomy around non-contractible loops. This is in fact the mathematical origin of the Aharonov-Bohm effect. I quantize this theory using standard field theoretical methods. The functional integral defining the scalar product is shown to reduce to a finite dimensional integral over moduli space. A non-trivial measure given by the Faddeev-Popov determinant is derived. I argue that the scalar product obtained coincides with the one used in Loop Quantum Gravity. I provide an explicit derivation in the case of a single defect-line, corresponding to a single loop in Loop Quantum Gravity. Moreover, I discuss the relation with spin-networks as used in the context of spin foam models.

Eugenio Bianchi
2009-09-10

120

Quantum motion in superposition of Aharonov-Bohm with some additional electromagnetic fields

  Mathematical Physics (arXiv)

Summary: The structure of additional electromagnetic fields to the Aharonov-Bohm field, for which the Schr\\"odinger, Klein-Gordon, and Dirac equations can be solved exactly are described and the corresponding exact solutions are found. It is demonstrated that aside from the known cases (a constant and uniform magnetic field that is parallel to the Aharonov-Bohm solenoid, a static spherically symmetrical electric field, and the field of a magnetic monopole), there are broad classes of additional fields. Among these new additional fields we have physically interesting electric fields acting during a finite time, or localized in a restricted region of space. There are additional time-dependent uniform and isotropic electric fields that allow exact solutions of the Schrodinger equation. In the relativistic case there are additional electric fields propagating along the Aharonov-Bohm solenoid with arbitrary electric pulse shape.

V. G. Bagrov; D. M. Gitman; A. D. Levin
2011-03-29

121

The K-Theoretic Formulation of D-Brane Aharonov-Bohm Phases

  HEP - Theory (arXiv)

Summary: The topological calculation of Aharonov-Bohm phases associated with D-branes in the absence of a Neveu-Schwarz B-field is explored. The K-theoretic classification of Ramond-Ramond fields in Type II and Type I theories is used to produce formulae for the Aharonov-Bohm phase associated with a torsion flux. A topological construction shows that K-theoretic pairings to calculate such phases exist and are well-defined. An analytic perspective is then taken, obtaining a means for determining Aharonov-Bohm phases by way of the reduced eta-invariant. This perspective is used to calculate the phase for an experiment involving the $(-1)-8$ system in Type I theory, and compared with previous calculations performed using different methods.

Aaron R. Warren
2012-11-26

122

The Crucial Role of Inert Source in the Magnetic Aharonov-Bohm Effect

  CERN Preprints

Summary: The role of the inert magnetic source used in the Tonomura experiment that has confirmed the magnetic Aharonov-Bohm effect is discussed. For this purpose, an analysis of a thought experiment is carried out. Here the permanent magnet is replaced by a classical source which is made of an ideal coil. A detailed calculation of this noninert source proves that in this case the effect disappears. This outcome provides another support for the crucial role of an inert source in the Aharonov-Bohm effect. A new aspect of quantum nonlocality is pointed out.

Comay, E
2009-01-01

123

Quantum Faraday Effect in Double-Dot Aharonov-Bohm Ring

  CERN Preprints

Summary: We investigate Faraday's law of induction manifested in the quantum state of Aharonov-Bohm loops. In particular, we propose a flux-switching experiment for a double-dot AB ring to verify the phase shift induced by Faraday's law. We show that the induced {\\em Faraday phase} is geometric and nontopological. Our study demonstrates that the relation between the local phases of a ring at different fluxes is not arbitrary but is instead determined by Faraday's inductive law, which is in strong contrast to the arbitrary local phase of an Aharonov-Bohm ring for a given flux.

Kang, Kicheon
2011-01-01

124

Quantum Faraday Effect in Double-Dot Aharonov-Bohm Ring

  Quantum Physics (arXiv)

Summary: We investigate Faraday's law of induction manifested in the quantum state of Aharonov-Bohm loops. In particular, we propose a flux-switching experiment for a double-dot AB ring to verify the phase shift induced by Faraday's law. We show that the induced {\\em Faraday phase} is geometric and nontopological. Our study demonstrates that the relation between the local phases of a ring at different fluxes is not arbitrary but is instead determined by Faraday's inductive law, which is in strong contrast to the arbitrary local phase of an Aharonov-Bohm ring for a given flux.

Kicheon Kang
2011-02-25

125

Entanglement between static and flying qubits in an Aharonov-Bohm double electrometer

  Quantum Physics (arXiv)

Summary: We consider the phase-coherent transport of electrons passing through an Aharonov-Bohm ring while interacting with a tunnel charge in a double quantum dot (representing a charge qubit) which couples symmetrically to both arms of the ring. For Aharonov-Bohm flux Phi_AB=h/2e we find that electrons can only be transmitted when they flip the charge qubit's pseudospin parity an odd number of times. The perfect correlations of the dynamics of the pseudospin and individual electronic transmission and reflection events can be used to entangle the charge qubit with an individual passing electron.

Henning Schomerus; John P. Robinson
2007-10-31

126

Aharonov-Bohm scattering of neutral atoms with induced electric dipole moments

  Quantum Physics (arXiv)

Summary: We investigate the scattering of neutral polarizable atoms from an electrically charged wire placed in a homogeneous magnetic field. The atoms carry an induced electric dipole. The reflecting wire is discussed. We calculate the scattering amplitude and cross section the practically more important case that atoms are totally absorbed at the surface of the wire. If the magnetic field is present, there is a dominating Aharonov-Bohm peak in the forward direction followed by decreasing oscillations for larger angles. An experimental realization of this modulated Aharonov-Bohm scattering should be possible.

Juergen Audretsch; Vladimir Skarzhinsky
1998-02-25

127

The Aharonov-Bohm effect: A quantum or a relativistic phenomenon?

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm effect is considered by most authors as a quantum effect, but a generally accepted explanation does not seem to be available. The phenomenon is studied here under the assumption that hypothetical electric dipole distributions configured by moving charges in the solenoid act on the electrons as test particles. The relative motions of the interacting charged particles introduce relativistic time dilations. The massless dipoles are postulated as part of an impact model that has recently been proposed to account for the far-reaching electrostatic forces between charged particles described by Coulomb's law. The model provides a quantitative explanation of the Aharonov-Bohm effect.

K. Wilhelm; B. N. Dwivedi
2014-08-23

128

The Aharonov-Bohm effect in spectral asymptotics of the magnetic Schrödinger operator

  Mathematical Physics (arXiv)

Summary: We show that in the absence of a magnetic field the spectrum of the magnetic Schr\\"odinger operator in an annulus depends on the cosine of the flux associated with the magnetic potential. This result follows from an analysis of a singularity in the wave trace for this Schr\\"odinger operator, and hence shows that even in the absence of a magnetic field the magnetic potential can change the asymptotics of the Schr\\"odinger spectrum, i.e. the Aharonov-Bohm effect takes place. We also study the Aharonov-Bohm effect for the magnetic Schr\\"odinger operator on a torus.

Gregory Eskin; James Ralston
2013-12-12

129

On the Path Integral Treatment for an Aharonov-Bohm Field on the Hyperbolic Plane

  Quantum Physics (arXiv)

Summary: In this paper I discuss by means of path integrals the quantum dynamics of a charged particle on the hyperbolic plane under the influence of an Aharonov-Bohm gauge field. The path integral can be solved in terms of an expansion of the homotopy classes of paths. I discuss the interference pattern of scattering by an Aharonov-Bohm gauge field in the flat space limit, yielding a characteristic oscillating behavior in terms of the field strength. In addition, the cases of the isotropic Higgs-oscillator and the Kepler-Coulomb potential on the hyperbolic plane are shortly sketched.

Christian Grosche
1998-08-27

130

Non-Abelian Chern-Simons Quantum Mechanics and Non-Abelian Aharonov-Bohm Effect

  HEP - Theory (arXiv)

Summary: We construct a classical action for a system of $N$ point-like sources which carry SU(2) non-Abelian charges coupled to non-Abelian Chern-Simons gauge fields, and develop a quantum mechanics for them. Adopting the coherent state quantization and solving the Gauss' constraint in an appropriately chosen gauge, we obtain a quantum mechanical Hamiltonian given in terms of the Knizhnik-Zamolodchikov connection. Then we study the non-Abelian Aharonov-Bohm effect, employing the obtained Hamiltonian for two-particle sector. An explicit evaluation of the differential cross section for the non-Abelian Aharonov-Bohm scattering is given.

Taejin Lee; Phillial Oh
1993-12-20

131

The Crucial Role of Inert Source in the Magnetic Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: The role of the inert magnetic source used in the Tonomura experiment that has confirmed the magnetic Aharonov-Bohm effect is discussed. For this purpose, an analysis of a thought experiment is carried out. Here the permanent magnet is replaced by a classical source which is made of an ideal coil. A detailed calculation of this noninert source proves that in this case the effect disappears. This outcome provides another support for the crucial role of an inert source in the Aharonov-Bohm effect. A new aspect of quantum nonlocality is pointed out.

E. Comay
2009-10-17

132

A Simple Proof of Magnetic and Electric Aharonov-Bohm Effects

  Mathematical Physics (arXiv)

Summary: Magnetic Aharonov-Bohm effect (AB effect) was studied in hundreds of papers starting with the seminal paper of Aharonov and Bohm [AB] published in 1959. We give a new proof of the magnetic Aharonov-Bohm effect without using the scattering theory and the theory of inverse boundary value problems. We consider separately the cases of one and several obstacles. The electric AB effect was studied much less. We give the first proof of the electric AB effect in domains with moving boundaries. When the boundary does not move with the time the electric AB effect is absent.

Gregory Eskin
2014-07-20

133

Stokes' theorem, gauge symmetry and the time-dependent Aharonov-Bohm effect

  CERN Preprints

Summary: Stokes' theorem is investigated in the context of the time-dependent Aharonov-Bohm effect -- the two-slit quantum interference experiment with a time varying solenoid between the slits. The time varying solenoid produces an electric field which leads to an additional phase shift which is found to exactly cancel the time-dependent part of the usual magnetic Aharonov-Bohm phase shift. This electric field arises from a combination of a non-single valued scalar potential and/or a 3-vector potential. The gauge transformation which leads to the scalar and 3-vector potentials for the electric field is non-single valued. This feature is connected with the non-simply connected topology of the Aharonov-Bohm set-up. The non-single valued nature of the gauge transformation function has interesting consequences for the 4-dimensional Stokes' theorem for the time-dependent Aharonov-Bohm effect. An experimental test of these conclusions is proposed.

Macdougall, James
2013-01-01

134

A Tunable Fano System Realized in a Quantum Dot in an Aharonov-Bohm Ring

  Materials Science Websites

Summary: -8581, Japan Abstract. We report a tunable Fano system realized in a quantum dot embedded in an Aharonov]. It can be viewed as a theory describing how a localized state embedded in the continuum acquires a tunable Fano experiment performed in a QD embedded in an Aharonov-Bohm (AB) interferometer [10

Katsumoto, Shingo

135

Electron-positron pair production in the Aharonov-Bohm potential

  HEP - Theory (arXiv)

Summary: In the framework of QED we evaluate the cross section for electron-positron pair production by a single photon in the presence of the external Aharonov-Bohm potential in first order of perturbation theory. We analyse energy, angular and polarization distributions at different energy regimes: near the threshold and at high photon energies.

V. D. Skarzhinsky; J. Audretsch; Ulf. Jasper
1997-09-18

136

Comments on ``Differential cross section for Aharonov-Bohm effect with nonstandard boundary conditions''

  Quantum Physics (arXiv)

Summary: We show that the violation of rotational symmetry for differential cross section for Aharonov-Bohm effect with nonstandard boundary conditions has been known for some time. Moreover, the results were applied to discuss the Hall effect and persistent currents of fermions in a plane pierced by a flux tube.

Alexander Moroz
1999-07-14

137

Eigenvalue estimates for the Aharonov-Bohm operator in a domain

  Mathematical Physics (arXiv)

Summary: We prove semi-classical estimates on moments of eigenvalues of the Aharonov-Bohm operator in bounded two-dimensional domains. Moreover, we present a counterexample to the generalized diamagnetic inequality which was proposed by Erdos, Loss and Vougalter. Numerical studies complement these results.

Rupert L. Frank; Anders Hansson
2007-10-04

138

Impurity effects on the Aharonov-Bohm optical signatures of neutral quantum-ring magnetoexcitons

  Physics Websites

Summary: Impurity effects on the Aharonov-Bohm optical signatures of neutral quantum-ring magnetoexcitons L are confined on a ring structure (quantum rings) as well as on a type-II quantum dot. Despite their neutral appears when one considers a system of bound charged particles, forming a composite neutral ob- ject

Dias, Luis Gregório

139

The phase of Hidden Momentum in Aharonov-Bohm solenoid effect

  Quantum Physics (arXiv)

Summary: It is shown that the phase of the hidden momentum in Aharonov-Bohm (AB) solenoid effect is equal in magnitude to the phase of the electron but with opposite sign. The phase of the hidden momentum is equal to that obtained by the energy of interference calculated in our previous paper (J.Opt.Soc.Am. B 17, 2052 2000).

Y. Ben-Aryeh
2012-01-03

140

Vortex vs spinning string: Iordanskii force and gravitational Aharonov-Bohm effect

  HEP - Theory (arXiv)

Summary: We discuss the transverse force acting on the spinning cosmic string, moving in the background matter. It comes from the gravitational Aharonov-Bohm effect and corresponds to the Iordanskii force acting on the vortex in superfluids, when the vortex moves with respect to the normal component of the liquid.

G. E. Volovik
1998-05-10

141

Differential cross section for Aharonov--Bohm effect with non standard boundary conditions

  Quantum Physics (arXiv)

Summary: A basic analysis is provided for the differential cross section characterizing Aharonov--Bohm effect with non standard (non regular) boundary conditions imposed on a wave function at the potential barrier. If compared with the standard case two new features can occur: a violation of rotational symmetry and a more significant backward scattering.

P. Stovicek; O. Vana
1998-10-23

142

Modular Momentum of the Aharonov-Bohm Effect on Noncommutative Lattices

  Mathematical Physics (arXiv)

Summary: Based on the technique of noncommutative geometry, it is shown that, by means of the concept of the theta quantization, there is an equivalence between the notion of the modular momentum of the Aharonov-Bohm effect and the notion of a noncommutative lattice over a circle poset.

Takeo Miura
2012-07-23

143

Aharonov-Bohm-like effect for light propagating in nematics with disclinations

  Condensed Matter (arXiv)

Summary: Using a geometric approach for the propagation of light in anisotropic media, we investigate what effect the director field of disclinations may have on the polarization state of light. Parallel transport around the defect, of the spinor describing the polarization, indicates the acquisition of a topological phase, in analogy with the Aharonov-Bohm effect.

A. M. de M. Carvalho; C. Satiro; F. Moraes
2007-09-20

144

Aharonov-Bohm Effect on Noncommutative Plane: A Coherent State Approach

  HEP - Theory (arXiv)

Summary: We apply the coherent state approach to study Aharonov-Bohm effect in the field theory context. We verify that, contrarily to the commutative result, the scattering amplitude is ultraviolet finite. However, we have logarithmic singularities as the noncommutative parameter tends to zero. Thus, the inclusion of a quartic self-interaction for the scalar field is necessary to obtain a smooth commutative limit.

M. A. Anacleto; J. R. Nascimento; A. Yu. Petrov
2006-05-04

145

The Interference Term in the Wigner Distribution Function and the Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: A phase space representation of the Aharonov-Bohm effect is presented. It shows that the shift of interference fringes is associated to the interference term of the Wigner distribution function of the total wavefunction, whereas the interference pattern is defined by the common projections of the Wigner distribution functions of the interfering beams

Daniela Dragoman
2004-02-23

146

Stokes' theorem, gauge symmetry and the time-dependent Aharonov-Bohm effect

  Mathematical Physics (arXiv)

Summary: Stokes' theorem is investigated in the context of the time-dependent Aharonov-Bohm effect -- the two-slit quantum interference experiment with a time varying solenoid between the slits. The time varying solenoid produces an electric field which leads to an additional phase shift which is found to exactly cancel the time-dependent part of the usual magnetic Aharonov-Bohm phase shift. This electric field arises from a combination of a non-single valued scalar potential and/or a 3-vector potential. The gauge transformation which leads to the scalar and 3-vector potentials for the electric field is non-single valued. This feature is connected with the non-simply connected topology of the Aharonov-Bohm set-up. The non-single valued nature of the gauge transformation function has interesting consequences for the 4-dimensional Stokes' theorem for the time-dependent Aharonov-Bohm effect. An experimental test of these conclusions is proposed.

James Macdougall; Douglas Singleton
2014-03-11

147

On the feasibility of detecting an Aharonov-Bohm phase shift in neutral matter

  Physics Websites

Summary: an experimental arrangement to test their prediction. The physical configuration involves neutral particlesOn the feasibility of detecting an Aharonov-Bohm phase shift in neutral matter Yuki Sato with the opposite charges in the induced electric dipole moment of the neutral 4 He atoms. We briefly review

Packard, Richard E.

148

Tunable Pseudogap Kondo Effect and Quantum Phase Transitions in Aharonov-Bohm Interferometers

  Physics Websites

Summary: dots embedded in the arms of an Aharonov-Bohm ring threaded by a magnetic flux. This system can realization of the pseudogap Kondo effect. The conductance and trans- mission phase shifts reflect.21.La, 65.80.+n, 72.10.Fk Nanoscale quantum-dot devices are a formidable tool for probing the inherent

Dias, Luis Gregório

149

Free and bound spin-polarized fermions in the fields of Aharonov--Bohm kind

  CERN Preprints

Summary: The scattering of electrons by an Aharonov--Bohm field is considered from the viewpoint of quantum-mechanical problem of constructing a self-adjoint Hamiltonian for the Pauli equation. The correct domain for the self-adjoint Hamiltonian, which takes into account explicitly the electron spin is found. A one-parameter self-adjoint extension of the Hamiltonian for spin-polarized electrons in the Aharonov--Bohm field is selected. The correct domain of the self-adjoint Hamiltonian can contain regular and singular (at the point ${\\bf r}=0$) square-integrable functions on the half-line with measure $rdr$. We argue that the physical reason of the existence of singular functions is the additional attractive potential, which appear due to the interaction between the spin magnetic moment of fermion and Aharonov--Bohm magnetic field. The scattering amplitude and cross section are obtained for spin-polarized electrons scattered by the Aharonov--Bohm field. It is shown that in some range of the extension parameter there ap...

Khalilov, V R; Eun, Lee Ki
2010-01-01

150

Phase measurements in quantum mechanics: The Aharonov-Bohm interferometer and quantum noise

  Chemistry Websites

Summary: Phase measurements in quantum mechanics: The Aharonov-Bohm interferometer and quantum noise When affected by the finite width of the interferometer's arms (see Fig. 2). Given the complications on the quantum dot, which sits on one arm, and with the magnetic field B in the center. #12;

Vardi, Amichay

151

AharonovBohm-type Effects in Triangular Antidot Lattice Yaushiro IYE

  Physics Websites

Summary: -type oscillation as a function of gate voltage gives infomation on the profile of the self-consistent potential, Chiba 277-8581 (Received August 10, 2004) Three kinds of Aharonov­Bohm (AB)-type oscillation have been. The oscillation periods of Altshuler­Aronov­Spivak (AAS) effect and AB-type effect near zero magnetic field

Iye, Yasuhiro

152

Aharonov-Bohm oscillations in the exciton luminescence from a semiconductor nanoring

  Computer Technologies and Information Sciences Websites

Summary: Aharonov-Bohm oscillations in the exciton luminescence from a semiconductor nanoring R. A. Romer 1- luminescence peak exhibit periodic oscillations as a function of magnetic ux threading the ring. The period exciton luminescence from a single quantum dot [1{13], and, thus, to avoid ambiguity in interpretation

Chemnitz, Technische Universität

153

Conductance of interacting Aharonov-Bohm systems and A. Ramsak1,2

  Materials Science Websites

Summary: May 2003; published 15 July 2003 A simple formula for the zero-temperature linear response conductance is presented. The formula is valid for a general interacting system exhibiting Fermi liquid properties. As an example of the efficiency of the formula the results for the conductance of a simple Aharonov-Bohm ring

Ramsak, Anton

154

Bound States of the Hydrogen Atom in the Presence of a Magnetic Monopole Field and an Aharonov-Bohm Potential

  HEP - Theory (arXiv)

Summary: In the present article we analyze the bound states of an electron in a Coulomb field when an Aharonov-Bohm field as well as a magnetic Dirac monopole are present. We solve, via separation of variables, the Schr\\"odinger equation in spherical coordinates and we show how the Hydrogen energy spectrum depends on the Aharonov-Bohm and the magnetic monopole strengths. In passing, the Klein-Gordon equation is solved.

Victor M. Villalba
1994-09-19

155

Against a proposed alternative explanation of the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm effect is understood to demonstrate that the Maxwell fields can act nonlocally in some situations. However it has been suggested from time to time that the AB effect is somehow a consequence of a local classical electromagnetic field phenomenon involving energy that is temporarily stored in the overlap between the external field and the field of which the beam particle is the source. That idea was shown in the past not to work for some models of the source of the external field. Here a more general proof is presented for the magnetic AB effect to show that the overlap energy is always compensated by another contribution to the energy of the magnetic field in such a way that the sum of the two is independent of the external flux. Therefore no such mechanism can underlie the Aharonov-Bohm effect.

Murray Peshkin
2010-09-08

156

Quantum Theories on Noncommutative Spaces with Nontrivial Topology: Aharonov-Bohm and Casimir Effects

  HEP - Theory (arXiv)

Summary: After discussing the peculiarities of quantum systems on noncommutative (NC) spaces with non-trivial topology and the operator representation of the $\\star$-product on them, we consider the Aharonov-Bohm and Casimir effects for such spaces. For the case of the Aharonov-Bohm effect, we have obtained an explicit expression for the shift of the phase, which is gauge invariant in the NC sense. The Casimir energy of a field theory on a NC cylinder is divergent, while it becomes finite on a torus, when the dimensionless parameter of noncommutativity is a rational number. The latter corresponds to a well-defined physical picture. Certain distinctions from other treatments based on a different way of taking the noncommutativity into account are also discussed.

M. Chaichian; A. Demichev; P. Presnajder; M. M. Sheikh-Jabbari; A. Tureanu
2001-07-07

157

The Aharonov-Casher Theorem and the Axial Anomaly in the Aharonov-Bohm Potential

  HEP - Phenomenology (arXiv)

Summary: The spectral properties of the Dirac Hamiltonian in the the Aharonov-Bohm potential are discussed. By using the Krein-Friedel formula, the density of states (DOS) for different self-adjoint extensions is calculated. As in the nonrelativistic case, whenever a bound state is present in the spectrum it is always accompanied by a (anti)resonance at the energy. The Aharonov-Casher theorem must be corrected for singular field configurations. There are no zero (threshold) modes in the Aharonov-Bohm potential. For our choice of the 2d Dirac Hamiltonian, the phase-shift flip is shown to occur at only positive energies. This flip gives rise to a surplus of the DOS at the lower threshold coming entirely from the continuous part of the spectrum. The results are applied to several physical quantities: the total energy, induced fermion-number, and the axial anomaly.

Alexander Moroz
1995-11-14

158

Correspondences and Quantum Description of Aharonov-Bohm and Aharonov-Casher Effects

  Quantum Physics (arXiv)

Summary: We establish systematic consolidation of the Aharonov-Bohm and Aharonov-Casher effects including their scalar counterparts. Their formal correspondences in acquiring topological phases are revealed on the basis of the gauge symmetry in non-simply connected spaces and the adiabatic condition for the state of magnetic dipoles. In addition, investigation of basic two-body interactions between an electric charge and a magnetic dipole clarifies their appropriate relative motions and discloses physical interrelations between the effects. Based on the two-body interaction, we also construct an exact microscopic description of the Aharonov-Bohm effect, where all the elements are treated on equal footing, i.e., magnetic dipoles are described quantum-mechanically and electromagnetic fields are quantized. This microscopic analysis not only confirms the conventional (semiclassical) results and the topological nature but also allows one to explore the fluctuation effects due to the precession of the magnetic dipoles with the adiabatic condition relaxed.

Minchul Lee; M. Y. Choi
2003-10-06

159

A Gravitational Aharonov-Bohm Effect, and its Connection to Parametric Oscillators and Gravitational Radiation

  CERN Preprints

Summary: A thought experiment is proposed to demonstrate the existence of a gravitational, vector Aharonov-Bohm effect. A connection is made between the gravitational, vector Aharonov-Bohm effect and the principle of local gauge invariance for nonrelativistic quantum matter interacting with weak gravitational fields. The compensating vector fields that are necessitated by this local gauge principle are shown to be incorporated by the DeWitt minimal coupling rule. The nonrelativistic Hamiltonian for weak, time-independent fields interacting with quantum matter is then extended to time-dependent fields, and applied to problem of the interaction of radiation with macroscopically coherent quantum systems, including the problem of gravitational radiation interacting with superconductors. But first we examine the interaction of EM radiation with superconductors in a parametric oscillator consisting of a superconducting wire placed at the center of a high Q superconducting cavity driven by pump microwaves. We find that the t...

Chiao, Raymond Y; Inan, Nader; Kang, Bong-Soo; Martinez, Luis A; Minter, Stephen J; Muñoz, Gerardo; Singleton, Douglas
2013-01-01

160

Noncommutative Correction to the Aharonov-Bohm Scattering: a Field Theory Approach

  HEP - Theory (arXiv)

Summary: We study a noncommutative nonrelativistic theory in 2+1 dimensions of a scalar field coupled to the Chern-Simons field. In the commutative situation this model has been used to simulate the Aharonov-Bohm effect in the field theory context. We verified that, contrarily to the commutative result, the inclusion of a quartic self-interaction of the scalar field is not necessary to secure the ultraviolet renormalizability of the model. However, to obtain a smooth commutative limit the presence of a quartic gauge invariant self-interaction is required. For small noncommutativity we fix the corrections to the Aharonov-Bohm scattering and prove that up to one-loop the model is free from dangerous infrared/ultraviolet divergences.

M. A. Anacleto; M. Gomes; A. J. da Silva; D. Spehler
2004-07-15

161

The time-dependent non-Abelian Aharonov-Bohm effect

  CERN Preprints

Summary: In this article, we study the {\\it time-dependent} Aharonov-Bohm effect for non-Abelian gauge fields. We use two well known time-dependent solutions to the Yang-Mills field equations to investigate the Aharonov-Bohm phase shift. For both of the solutions, we find a cancellation between the phase shift coming from the non-Abelian "magnetic" field and the phase shift coming from the non-Abelian "electric" field, which inevitably arises in time-dependent cases. We compare and contrast this cancellation for the time-dependent non-Abelian case to a similar cancellation which occurs in the time-dependent Abelian case. We postulate that this cancellation occurs generally in time-dependent situations for both Abelian and non-Abelian fields.

Bright, Max
2015-01-01

162

Nonrelativistic Limit of the Scalar Chern-Simons Theory and the Aharonov-Bohm Scattering

  HEP - Theory (arXiv)

Summary: We study the nonrelativistic limit of the quantum theory of a Chern-Simons field minimally coupled to a scalar field with quartic self-interaction. The renormalization of the relativistic model, in the Coulomb gauge, is discussed. We employ a procedure to calculate scattering amplitudes for low momenta that generates their $|p|/m$ expansion and separates the contributions coming from high and low energy intermediary states. The two body scattering amplitude is calculated up to order $p^2/m^2$. It is shown that the existence of a critical value of the self-interaction parameter for which the 2-particle scattering amplitude reduces to the Aharonov-Bohm one is a strictly nonrelativistic feature. The subdominant terms correspond to relativistic corrections to the Aharonov-Bohm scattering. A nonrelativistic reduction scheme and an effective nonrelativistic Lagrangian to account for the relativistic corrections are proposed.

M. Gomes; J. M. C. Malbouisson; A. J. da Silva
1998-01-28

163

Parity Violation in Aharonov-Bohm Systems: The Spontaneous Hall Effect

  HEP - Theory (arXiv)

Summary: We show how macroscopic manifestations of $P$ (and $T$) symmetry breaking can arise in a simple system subject to Aharonov-Bohm interactions. Specifically, we study the conductivity of a gas of charged particles moving through a dilute array of flux tubes. The interaction of the electrons with the flux tubes is taken to be of a purely Aharonov-Bohm type. We find that the system exhibits a non-zero transverse conductivity, i.e., a spontaneous Hall effect. This is in contrast with the fact that the cross sections for both scattering and bremsstrahlung (soft photon emission) of a single electron from a flux tube are invariant under reflections. We argue that the asymmetry in the conductivity coefficients arises from many-body effects. On the other hand, the transverse conductivity has the same dependence on universal constants that appears in the Quantum Hall Effect, a result that we relate to the validity of the Mean Field approximation.

R. Emparan; M. A. Valle Basagoiti
1993-12-21

164

Generalised boundary conditions for the Aharonov-Bohm e ect combined with

  Mathematics Websites

Summary: #28;eld P. Exner 1;3 , P. â??´oví£ek 2;3 , P. Vyt°as 2 1 Nuclear Physics Institute, Academy of Sciences, 250 68 �eº near Prague, Czech Republic 2 Department of Mathematics, Faculty of Nuclear Science, Czech-parameter family of boundary conditions; other two parameters of the model are the Aharonov-Bohm #29;ux


165

On the Electric Charge Quantization from the Dirac-Aharonov-Bohm Potential

  Quantum Physics (arXiv)

Summary: The purpose of this paper is to show that, under certain restrictions, we can take a Dirac-Aharonov-Bohm potential as a pure gauge field. We argue that a modified quantization condition comes out for the electric charge that may open up the way for the understanding of fractional charges. One does not need any longer to rely on the existence of a magnetic monopole to justify electric charge quantization.

F. A. Barone; J. A. Helayel-Neto
2005-06-20

166

The Hamiltonian in an Aharonov-Bohm gauge field and its self-adjoint extensions

  HEP - Theory (arXiv)

Summary: By using the spherical coordinates in 3+1 dimensions we study the self-adjointness of the Dirac Hamiltonian in an Aharonov-Bohm gauge field of an infinitely thin magnetic flux tube. It is shown that the angular part of the Dirac Hamiltonian requires self-adjoint extensions as well as its radial one. The self-adjoint extensions of the angular part are parametrized by 2x2 unitary matrix.

Kazuhiko Odaka; Kazuya Satoh
1996-04-16

167

Partial Wave Analysis of Scattering with Nonlocal Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: Partial wave theory of a two dimensional scattering problem for an arbitray short range potential and a nonlocal Aharonov-Bohm magnetic flux is established. The scattering process of a ``hard disk'' like potential and the magnetic flux is examined. Since the nonlocal influence of magnetic flux on the charged particles is universal, the nonlocal effect in hard disk case is expected to appear in quite general potential system and will be useful in understanding some phenomena in mesoscopic phyiscs.

de-Hone Lin
2003-11-05

168

On the alleged nonlocal and topological nature of the molecular Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The nonlocal and topological nature of the molecular Aharonov-Bohm (MAB) effect is examined for real electronic Hamiltonians. A notion of preferred gauge for MAB is suggested. The MAB effect in the linear + quadratic $E\\otimes \\epsilon$ Jahn-Teller system is shown to be essentially analogues to an anisotropic Aharonov-Casher effect for an electrically neutral spin$-{1/2}$ particle encircling a certain configuration of lines of charge.

Erik Sjöqvist
2004-09-09

169

Effects of Nongauge Potentials on the Spin-1/2 Aharonov-Bohm Problem

  HEP - Theory (arXiv)

Summary: Some recent work has attempted to show that the singular solutions which are known to occur in the Dirac description of spin-1/2 Aharonov-Bohm scattering can be eliminated by the inclusion of strongly repulsive potentials inside the flux tube. It is shown here that these calculations are generally unreliable since they necessarily require potentials which lead to the occurrence of Klein's paradox. To avoid that difficulty the problem is solved within the framework of the Galilean spin-1/2 wave equation which is free of that particular complication. It is then found that the singular solutions can be eliminated provided that the nongauge potential is made energy dependent. The effect of the inclusion of a Coulomb potential is also considered with the result being that the range of flux parameter for which singular solutions are allowed is only half as great as in the pure Aharonov-Bohm limit. Expressions are also obtained for the binding energies which can occur in the combined Aharonov-Bohm-Coulomb system.

C. R. Hagen
1993-08-10

170

Scattering of spin 1/2 particles by the 2+1 dimensional noncommutative Aharonov-Bohm potential

  HEP - Theory (arXiv)

Summary: In this work we study modifications in the Aharonov-Bohm effect for relativistic spin 1/2 particles due to the noncommutativity of spacetime in $2 + 1$ dimensions. The noncommutativity gives rise to a correction to the Aharonov-Bohm potential which is highly singular at the origin, producing divergences in a perturbative expansion around the usual solution of the free Dirac equation. This problem is surmounted by using a perturbative expansion around the exact solution of the \\textit{commutative} Aharonov-Bohm problem. We calculate, in this setting, the scattering amplitude and the corrections to the differential and total cross sections for a spin 1/2 particle, in the small-flux limit.

A. F. Ferrari; M. Gomes; C. A. Stechhahn
2007-08-28

171

Aharonov-Bohm effect and geometric phases -- Exact and approximate topology

  Mathematical Physics (arXiv)

Summary: By analyzing an exactly solvable model in the second quantized formulation which allows a unified treatment of adiabatic and non-adiabatic geometric phases, it is shown that the topology of the adiabatic Berry's phase, which is characterized by the singularity associated with possible level crossing, is trivial in a precise sense. This topology of the geometric phase is quite different from the topology of the Aharonov-Bohm effect, where the topology is specified by the external local gauge field and it is exact for the slow as well as for the fast motion of the electron.

Kazuo Fujikawa
2013-02-03

172

Scattering theory and the Aharonov--Bohm effect in quasiclassical physics

  HEP - Theory (arXiv)

Summary: Scattering of a nonrelativistic quantum-mechanical particle by an impenetrable magnetic vortex is considered. The nonvanishing transverse size of the vortex is taken into account, and the limit of short, as compared to this size, wavelengths of the scattered particle is analyzed. We show that the scattering Aharonov-Bohm effect persists in the quasiclassical limit owing to the diffraction persisting in the short-wavelength limit. As a result, the vortex flux serves as a gate for the propagation of short-wavelength, almost classical, particles. This quasiclassical effect is more feasible to experimental detection in the case when space outside the vortex is conical.

Yurii A. Sitenko; Nadiia D. Vlasii
2011-01-24

173

Scattering of a charged particle from a hard cylindrical solenoid: Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: The scattering amplitude of a charged particle from a long hard cylinderical solenoid is derived by solving the time independent Schr\\"{o}dinger equation on a double connected plane. It is a summation over the angular momentum quantum number (partial wave summation). It is shown that only negative mechanical angular momenta contribute to the amplitude when the radius of the solenoid goes to zero limit without varying the magnetic induction flux (Flux line). Original Aharonov-Bohm result is obtained with this limit.

Oktay Yilmaz
2014-02-26

174

Scattering of spin-polarized electron in an Aharonov--Bohm potential

  Mathematical Physics (arXiv)

Summary: The scattering of spin-polarized electrons in an Aharonov--Bohm vector potential is considered. We solve the Pauli equation in 3+1 dimensions taking into account explicitly the interaction between the three-dimensional spin magnetic moment of electron and magnetic field. Expressions for the scattering amplitude and the cross section are obtained for spin-polarized electron scattered off a flux tube of small radius. It is also shown that bound electron states cannot occur in this quantum system. The scattering problem for the model of a flux tube of zero radius in the Born approximation is briefly discussed.

V. R. Khalilov; Choon-Lin Ho
2007-10-05

175

The Sagnac Phase Shift suggested by the Aharonov-Bohm effect for relativistic matter beams

  General Relativity & Quantum Cosmology (arXiv)

Summary: The phase shift due to the Sagnac Effect, for relativistic matter beams counter-propagating in a rotating interferometer, is deduced on the bases of a a formal analogy with the the Aharonov-Bohm effect. A procedure outlined by Sakurai, in which non relativistic quantum mechanics and newtonian physics appear together with some intrinsically relativistic elements, is generalized to a fully relativistic context, using the Cattaneo's splitting technique. This approach leads to an exact derivation, in a self-consistently relativistic way, of the Sagnac effect. Sakurai's result is recovered in the first order approximation.

Guido Rizzi; Matteo Luca Ruggiero
2003-05-13

176

Semiclassical Theory of h/e Aharonov-Bohm Oscillation in Ballistic Regimes

  Nonlinear Sciences (arXiv)

Summary: We study the magneto-transport in Aharonov-Bohm (AB) billiards forming doubly connected structures. In these systems, non-averaged conductance oscillates as a function of magnetic flux with period h/e. We derive formulas of the correlation function C of the magneto-conductance for chaotic and regular AB billiards by use of the semiclassical theory. The different higher harmonics behaviors for C are related to the differing distribution of classical dwelling times. The AB oscillation in ballistic regimes provides an experimental probe of quantum signatures of classical chaotic and regular dynamics.

Shiro Kawabata
1999-09-01

177

Anyonic strings and membranes in AdS space and dual Aharonov-Bohm effects

  HEP - Theory (arXiv)

Summary: It is observed that strings in AdS_5 x S^5 and membranes in AdS_7 x S^4 exhibit long range phase interactions. Two well separated membranes dragged around one another in AdS acquire phases of 2\\pi/N. The same phases are acquired by a well separated F and D string dragged around one another. The phases are shown to correspond to both the standard and a novel type of Aharonov-Bohm effect in the dual field theory.

Sean A. Hartnoll
2006-12-15

178

h/2e oscillations and quantum chaos in ballistic Aharonov-Bohm billiards

  Nonlinear Sciences (arXiv)

Summary: We study the quantum interference effect for the single ballistic Aharonov-Bohm billiard in the presence of a weak magnetic field B. The diagonal part of the wave-number averaged reflection coefficient $\\delta {\\cal R}_D$ is calculated by use of semi-classical scattering theory. In addition to the appearance of "h/2e oscillation" that are caused by interference between time-reversed coherent backscattering classical trajectories, B in the conducting region leads to negative magnetoresistance and dampening of the h/2e oscillation amplitude. The B dependence of the results reflects the underlying classical (chaotic and regular) dynamics.

Shiro Kawabata; Katsuhiro Nakamura
2000-02-05

179

Semiclassical theory of h/e Aharonov-Bohm oscillation for doubly connected ballistic cavities

  Nonlinear Sciences (arXiv)

Summary: In Aharonov-Bohm (AB) cavities forming doubly connected ballistic structures, h/e AB oscillations that result from the interference among the complicated trapped paths in the cavity can be described by the framework of the semiclassical theory. We derive formulas of the correlation function C(\\Delta \\phi) of the nonaveraged magnetoconductance for chaotic and regular AB cavities. The different higher harmonics behaviors for C(\\Delta \\phi) are related to the differing distribution of classical dwelling times. The AB oscillation in ballistic regimes provides an experimental probe of quantum signatures of classical chaotic and regular dynamics.

Shiro Kawabata
2000-02-04

180

Weighted dispersive estimates for two-dimensional Schrödinger operators with Aharonov-Bohm magnetic field

  Mathematical Physics (arXiv)

Summary: We consider two-dimensional Schr\\"odinger operators $H$ with Aharonov-Bohm magnetic field and an additional electric potential. We obtain an explicit leading term of the asymptotic expansion of the unitary group $e^{-i t H}$ for $t\\to\\infty$ in weighted $L^2$ spaces. In particular, we show that the magnetic field improves the decay of $e^{-i t H}$ with respect to the unitary group generated by non-magnetic Schr\\"odinger operators, and that the decay rate in time is determined by the magnetic flux.

Gabriele Grillo; Hynek Kovarik
2014-03-14

181

Zero modes in a system of Aharonov--Bohm solenoids on the Lobachevsky plane

  Mathematical Physics (arXiv)

Summary: We consider a spin 1/2 charged particle on the Lobachevsky plane subjected to a magnetic field corresponding to a discrete system of Aharonov-Bohm solenoids. Let $H^+$ and $H^-$ be the two components of the Pauli operator for spin up and down, respectively. We show that neither $H^+$ nor $H^-$ has a zero mode if the number of solenoids is finite. On the other hand, a construction is described of an infinite periodic system of solenoids for which either $H^+$ or $H^-$ has zero modes depending on the value of the flux carried by the solenoids.

V. A. Geyler; P. Stovicek
2005-09-01

182

Analogue Aharonov-Bohm effect in a Lorentz-violating background

  HEP - Theory (arXiv)

Summary: In this paper we consider the acoustic black hole metrics obtained from a relativistic fluid under the influence of constant background that violates the Lorentz symmetry to study the analogue of the Aharonov-Bohm (AB) effect. We show that the scattering of planar waves by a draining bathtub vortex leads to a modified AB effect and due to the Lorentz symmetry breaking, the phase shift persists even in the limit where the parameters associated with the circulation and draining vanish. In this limit, the Lorentz-violating background forms a conical defect, which is also responsible for the appearance of the analogue AB effect.

M. A. Anacleto; F. A. Brito; E. Passos
2012-12-11

183

The Paradoxical Forces for the Classical Electromagnetic Lag Associated with the Aharonov-Bohm Phase Shift

  Physics (arXiv)

Summary: The classical electromagnetic lag assocated with the Aharonov-Bohm phase shift is obtained by using a Darwin-Lagrangian analysis similar to that given by Coleman and Van Vleck to identify the puzzling forces of the Shockley-James paradox. The classical forces cause changes in particle velocities and so produce a relative lag leading to the same phase shift as predicted by Aharonov and Bohm and observed in experiments. An experiment is proposed to test for this lag aspect implied by the classical analysis but not present in the currently-accepted quantum topological description of the phase shift.

Timothy H. Boyer
2005-06-23

184

Influence of Induced Charges in the Electric Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: This paper states that the induced charge should not be neglected in the electric Aharonov-Bohm effect. If the induced charge is taken into account, the interference pattern of the moving charge will not change with the potential difference between the two metal tubes. It means that the scale potential itself can not affect the phase of the moving charge, and the true factor affecting the phase of the moving charge is the energy of the system including the moving charge and the induced charge.

Rui-Feng Wang
2014-09-24

185

A Remark on the Aharonov-Bohm Potential and a Discussion on the Electric Charge Quantization

  Quantum Physics (arXiv)

Summary: The purpose of this work is to stress on a mathematical requirement of the Stokes' theorem that, naturally, yields a reassessment of the electric charge quantization condition, which is, here, explicitly carried out in the context of the Aharonov-Bohm set-up. We argue that, by virtue of an ambiguity in the definition of the circulation of the vector potential, a modified quantization condition comes out for the electric charge that opens the way for understanding fundamental fractional charges. One does not, any longer, need to rely on the existence of a magnetic monopole to justify electric charge quantization.

F. A. Barone; J. A. Helayel-Neto
2005-02-08

186

Dephasing via stochastic absorption: A case study in Aharonov-Bohm oscillations

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm ring has been the mainstay of mesoscopic physics research since its inception. In this paper we have dwelt on the problem of dephasing of AB oscillations using a phenomenological model based on stochastic absorption. To calculate the conductance in the presence of inelastic scattering we have used the method due to Brouwer and Beenakker. We have shown that conductance is symmetric under flux reversal and visibility of AB oscillations decay to zero as a function of the incoherence parameter thus signalling dephasing in the system. Some comments are made on the relative merits of stochastic absorption with respect to optical potential model, which have been used to mimic dephasing.

Colin Benjamin; A. M. Jayannavar
2002-04-01

187

Electromagnetism, local covariance, the Aharonov-Bohm effect and Gauss' law

  CERN Preprints

Summary: We quantise the massless vector potential A of electromagnetism in the presence of a classical electromagnetic (background) current, j, in a generally covariant way on arbitrary globally hyperbolic spacetimes M. By carefully following general principles and procedures we clarify a number of topological issues. First we combine the interpretation of A as a connection on a principal U(1)-bundle with the perspective of general covariance to deduce a physical gauge equivalence relation, which is intimately related to the Aharonov-Bohm effect. By Peierls' method we subsequently find a Poisson bracket on the space of local, affine observables of the theory. This Poisson bracket is in general degenerate, leading to a quantum theory with non-local behaviour. We show that this non-local behaviour can be fully explained in terms of Gauss' law. Thus our analysis establishes a relationship, via the Poisson bracket, between the Aharonov-Bohm effect and Gauss' law (a relationship which seems to have gone unnoticed so far)....

Sanders, Ko; Hack, Thomas-Paul
2012-01-01

188

A Gravitational Aharonov-Bohm Effect, and its Connection to Parametric Oscillators and Gravitational Radiation

  General Relativity & Quantum Cosmology (arXiv)

Summary: A thought experiment is proposed to demonstrate the existence of a gravitational, vector Aharonov-Bohm effect. A connection is made between the gravitational, vector Aharonov-Bohm effect and the principle of local gauge invariance for nonrelativistic quantum matter interacting with weak gravitational fields. The compensating vector fields that are necessitated by this local gauge principle are shown to be incorporated by the DeWitt minimal coupling rule. The nonrelativistic Hamiltonian for weak, time-independent fields interacting with quantum matter is then extended to time-dependent fields, and applied to problem of the interaction of radiation with macroscopically coherent quantum systems, including the problem of gravitational radiation interacting with superconductors. But first we examine the interaction of EM radiation with superconductors in a parametric oscillator consisting of a superconducting wire placed at the center of a high Q superconducting cavity driven by pump microwaves. We find that the threshold for parametric oscillation for EM microwave generation is much lower for the separated configuration than the unseparated one, which then leads to an observable dynamical Casimir effect. We speculate that a separated parametric oscillator for generating coherent GR microwaves could also be built.

Raymond Y. Chiao; Robert W. Haun; Nader A. Inan; Bong-Soo Kang; Luis A. Martinez; Stephen J. Minter; Gerardo A. Muñoz; Douglas A. Singleton
2013-02-04

189

Aharonov-Bohm scattering of charged particles and neutral atoms: the role of absorption

  Quantum Physics (arXiv)

Summary: The Aharonov-Bohm scattering of charged particles by the magnetic field of an infinitely long and infinitely thin solenoid (magnetic string) in an absorbing medium is studied. We discuss the partial-wave approach to this problem and show that standard partial-wave method can be adjusted to this case. The effect of absorption leads to oscillations of the AB cross section. Based on this we investigate the scattering of neutral atoms with induced electric dipole moments by a charge wire of finite radius which is placed in an uniform magnetic field. The physical realistic and practically important case that all atoms which collide with the wire are totally absorbed at its surface, is studied in detail. The dominating terms of the scattering amplitude are evaluated analytically for different physical constellations. The rest terms are written in a form suitable for a numerical computation. We show that if the magnetic field is absent, the absorbing charged wire causes oscillations of the cross section. In the presence of the magnetic field the cross section increases and the dominating Aharonov--Bohm peak appears in the forward direction, suppressing the oscillations.

Juergen Audretsch; Vladimir Skarzhinsky
1999-01-25

190

PHYSICAL REVIEW B 86, 195403 (2012) Coherent control of double-dot molecules using Aharonov-Bohm magnetic flux

  Materials Science Websites

Summary: is susceptible to charge noises.13­15 In this paper, we show that for a uncoupled DQD in an Aharonov-Bohm (AB, controlling the charge coherence of the uncoupled DQD through the AB flux is very robust against charge noises an uncoupled DQD embedded in an AB interferometer, as shown in Fig. 1. In contrast to previous theoretical

Nori, Franco

191

Noncircular semiconductor nanorings of types I and II: Emission kinetics in the excitonic Aharonov-Bohm effect

  Materials Science Websites

Summary: are calculated, showing deviations from equilibrium. The presence of a nonradiative exciton decay leads to show a similar oscillating behavior. Origi- nally, a related many-body system has been studied by Wen out, but always using a rigid lateral confinement in the ring.7 For the exciton Aharonov-Bohm effect X

Zimmermann, Roland

192

Aharonov--Bohm E#ect in Scattering by a Chain of Point--like Magnetic Fields

  Mathematics Websites

Summary: Aharonov--Bohm E#ect in Scattering by a Chain of Point--like Magnetic Fields Hiroshi T. Ito the scattering by several point--like magnetic fields at large separation in two dimensions. We derive. Even if a magnetic field is compactly supported, the corresponding vector potential does


193

Aharonov-Bohm Effect and High-Velocity Estimates of Solutions to the Schr\\"odinger Equation

  CERN Preprints

Summary: The Aharonov-Bohm effect is a fundamental and controversial issue in physics. At stake are what are the fundamental electromagnetic quantities in quantum physics, if magnetic fields can act at a distance on charged particles and if the magnetic potentials have a real physical significance. From the experimental side the issues were settled by the remarkable experiments of Tonomura et al. in 1982 and 1986 with toroidal magnets that gave a strong experimental evidence of the physical existence of the Aharonov-Bohm effect, and by the recent experiment of Caprez et al. in 2007 that shows that the results of these experiments can not be explained by a force. The Aharonov-Bohm Ansatz of 1959 predicts the results of the experiments of Tonomura et al. and of Caprez et al. In 2009 we gave the first rigorous proof that the Aharonov-Bohm Ansatz is a good approximation to the exact solution for toroidal magnets under the conditions of the experiments of Tonomura et al.. In this paper we prove that our results do not depe...

Ballesteros, Miguel
2010-01-01

194

Dephasing by Extremely Dilute Magnetic Impurities Revealed by Aharonov-Bohm Oscillations F. Pierre and Norman O. Birge

  Materials Science Websites

Summary: Dephasing by Extremely Dilute Magnetic Impurities Revealed by Aharonov-Bohm Oscillations F. Pierre of at low temperature in weakly disordered metallic thin films is the presence of extremely dilute magnetic 48824-2320 (Received 28 June 2002; published 29 October 2002) We have probed the magnetic field

Birge, Norman

195

Magnetoresistance of nanoscale molecular devices based on Aharonov-Bohm interferometry This article has been downloaded from IOPscience. Please scroll down to see the full text article.

  Chemistry Websites

Summary: Magnetoresistance of nanoscale molecular devices based on Aharonov-Bohm interferometry This article molecular devices based on Aharonov­Bohm interferometry Oded Hod1 , Roi Baer2 and Eran Rabani3 1 Department

Rabani, Eran

196

Wave-packet rectification in nonlinear electronic systems: A tunable Aharonov-Bohm diode

  CERN Preprints

Summary: Rectification of electron wave-packets propagating along a quasi-one dimensional chain is commonly achieved via the simultaneous action of nonlinearity and longitudinal asymmetry, both confined to a limited portion of the chain termed wave diode. However, it is conceivable that, in the presence of an external magnetic field, spatial asymmetry perpendicular to the direction of propagation suffices to ensure rectification. This is the case of a nonlinear ring-shaped lattice with different upper and lower halves (diode), which is attached to two elastic chains (leads). The resulting device is mirror symmetric with respect to the ring vertical axis, but mirror asymmetric with respect to the chain direction. Wave propagation along the two diode paths can be modeled for simplicity by a discrete Schr\\"odinger equation with cubic nonlinearities. Numerical simulations demonstrate that, thanks to the Aharonov-Bohm effect, such a diode can be operated by tuning the magnetic flux across the ring.

Li, Yunyun; Marchesoni, Fabio; Li, Baowen
2014-01-01

197

Dynamics of coherences in the interacting double-dot Aharonov-Bohm interferometer: Exact numerical simulations

  Quantum Physics (arXiv)

Summary: We study the real time dynamics of electron coherence in a double quantum dot two-terminal Aharonov-Bohm geometry, taking into account repulsion effects between the dots' electrons. The system is simulated by extending a numerically exact path integral method, suitable for treating transport and dissipation in biased impurity models [Phys. Rev. B 82, 205323 (2010)]. Numerical simulations at finite interaction strength are supported by master equation calculations in two other limits: assuming non-interacting electrons, and working in the Coulomb blockade regime. Focusing on the intrinsic coherence dynamics between the double-dot states, we find that its temporal characteristics are preserved under weak-to-intermediate inter-dot Coulomb interaction. In contrast, in the Coulomb blockade limit, a master equation calculation predicts coherence dynamics and a steady-state value which notably deviate from the finite interaction case.

Salil Bedkihal; Dvira Segal
2012-01-13

198

Fermion pair production in planar Coulomb and Aharonov--Bohm potentials

  Mathematical Physics (arXiv)

Summary: Exact analytic solutions are found for the Dirac equation in 2+1 dimensions for a spin-one-half particle in a combination of the Lorentz 3-vector and scalar Coulomb as well as Aharonov--Bohm potentials. We employ the two-component Dirac equation which contains a new parameter introduced by Hagen to describe the spin of the spin-1/2 particle. We derive a transcendental equations that implicitly determine the energy spectrum of an electron near the negative-energy continuum boundary and the critical charges for some electron states. Fermion pair production from a vacuum by a strong Coulomb field in the presence of the magnetic flux tube of zero radius is considered. It is shown that the presence of the Ahanorov--Bohm flux tends to stabilize the system.

V. R. Khalilov; Choon-Lin Ho
2008-12-16

199

A proposal for investigating three-body forces in Aharonov-Bohm sytems

  Quantum Physics (arXiv)

Summary: Although there is no force on the electron in Aharonov-Bohm solenoid effect, the electron exerts a force on the solenoid related to the inequality of action and reaction forces of two subsystems in three-system configuration. The AB phase which is related to the force exerted by the electron on the solenoid . The momentum changes of the mechanical oscillator are equal in magnitude and opposite in sign to the changes in the momentum of the em fields. It is proposed to investigate momentum changes of "micro" bodies producing magnetic fields in AB systems which will clarify the nature of these effects. The problem of magnetic fields shielded from the electron wave packet is also discussed.

Y. Ben-Aryeh
2009-11-26

200

Aharonov-Bohm Effect in the Abelian-Projected SU(3)-QCD with $?$-term

  HEP - Theory (arXiv)

Summary: By making use of the path-integral duality transformation, string representation of the Abelian-projected SU(3)-QCD with the $\\Theta$-term is derived. Besides the short-range (self-)interactions of quarks (which due to the $\\Theta$-term acquire a nonvanishing magnetic charge, i.e. become dyons) and electric Abrikosov-Nielsen-Olesen strings, the resulting effective action contains also a long-range topological interaction of dyons with strings. This interaction, which has the form of the 4D Gauss linking number of the trajectory of a dyon with the world-sheet of a closed string, is shown to become nontrivial at $\\Theta$ not equal to $3\\pi$ times an integer. At these values of $\\Theta$, closed electric Abrikosov-Nielsen-Olesen strings in the model under study can be viewed as solenoids scattering dyons, which is the 4D analogue of the Aharonov-Bohm effect.

Dmitri Antonov
1999-11-29

201

The manifestly covariant Aharonov-Bohm effect in terms of the 4D fields

  CERN Preprints

Summary: In this paper it is presented a manifestly covariant formulation of the Aharonov-Bohm (AB) phase difference for the magnetic AB effect . This covariant AB phase is written in terms of the Faraday 2-form F and using the decomposition of F in terms of the electric and magnetic fields as four-dimensional (4D) geometric quantities. It is shown that there is a static electric field outside a stationary solenoid with resistive conductor carrying steady current, which causes that the AB phase difference in the magnetic AB effect may be determined by the electric part of the covariant expression, i.e. by the local influence of the 4D electric field and not, as generally accepted,in terms of nonzero vector potential.

Ivezic, Tomislav
2014-01-01

202

Aharonov-Bohm Effect in the Abelian-Projected SU(3)-QCD with $\\Theta$-term

  CERN Preprints

Summary: By making use of the path-integral duality transformation, string representation of the Abelian-projected SU(3)-QCD with the $\\Theta$-term is derived. Besides the short-range (self-)interactions of quarks (which due to the $\\Theta$-term acquire a nonvanishing magnetic charge, i.e. become dyons) and electric Abrikosov-Nielsen-Olesen strings, the resulting effective action contains also a long-range topological interaction of dyons with strings. This interaction, which has the form of the 4D Gauss linking number of the trajectory of a dyon with the world-sheet of a closed string, is shown to become nontrivial at $\\Theta$ not equal to $3\\pi$ times an integer. At these values of $\\Theta$, closed electric Abrikosov-Nielsen-Olesen strings in the model under study can be viewed as solenoids scattering dyons, which is the 4D analogue of the Aharonov-Bohm effect.

Antonov, D V
2000-01-01

203

Scattering of relativistic particles with Aharonov-Bohm-Coulomb interaction in two dimensions

  HEP - Theory (arXiv)

Summary: The Aharonov-Bohm-Coulomb potentials in two dimensions may describe the interaction between two particles carrying electric charge and magnetic flux, say, Chern--Simons solitons, or so called anyons. The scattering problem for such two-body systems is extended to the relativistic case, and the scattering amplitude is obtained as a partial wave series. The electric charge and magnetic flux is ($-q$, $-\\phi/Z$) for one particle and ($Zq$, $\\phi$) for the other. When $(Zq^2/\\hbar c)^2\\ll 1$, and $q\\phi/2\\pi\\hbar c$ takes on integer or half integer values, the partial wave series is summed up approximately to give a closed form. The results exhibit some nonperturbative features and cannot be obtained from perturbative quantum electrodynamics at the tree level.

Qiong-gui Lin
2000-07-27

204

Propagators associated to periodic Hamiltonians: an example of the Aharonov-Bohm Hamiltonian with two vortices

  Mathematical Physics (arXiv)

Summary: We consider an invariant quantum Hamiltonian $H=-\\Delta_{LB}+V$ in the $L^{2}$ space based on a Riemannian manifold $\\tilde{M}$ with a discrete symmetry group $\\Gamma$. Typically, $\\tilde{M}$ is the universal covering space of a multiply connected manifold $M$ and $\\Gamma$ is the fundamental group of $M$. To any unitary representation $\\Lambda$ of $\\Gamma$ one can relate another operator on $M=\\tilde{M}/\\Gamma$, called $H_\\Lambda$, which formally corresponds to the same differential operator as $H$ but which is determined by quasi-periodic boundary conditions. We give a brief review of the Bloch decomposition of $H$ and of a formula relating the propagators associated to the Hamiltonians $H_\\Lambda$ and $H$. Then we concentrate on the example of the Aharonov-Bohm effect with two vortices. We explain in detail the construction of the propagator in this case and indicate all essential intermediate steps.

P. Kocabova; P. Stovicek
2008-02-06

205

Effects of quantum deformation on the spin-1/2 Aharonov-Bohm problem

  Mathematical Physics (arXiv)

Summary: In this letter we study the Aharonov-Bohm problem for a spin-1/2 particle in the quantum deformed framework generated by the $\\kappa$-Poincar\\'{e}-Hopf algebra. We consider the nonrelativistic limit of the $\\kappa$-deformed Dirac equation and use the spin-dependent term to impose an upper bound on the magnitude of the deformation parameter $\\varepsilon$. By using the self-adjoint extension approach, we examine the scattering and bound state scenarios. After obtaining the scattering phase shift and the $S$-matrix, the bound states energies are obtained by analyzing the pole structure of the latter. Using a recently developed general regularization prescription [Phys. Rev. D. \\textbf{85}, 041701(R) (2012)], the self-adjoint extension parameter is determined in terms of the physics of the problem. For last, we analyze the problem of helicity conservation.

F. M. Andrade; E. O. Silva
2012-12-10

206

The manifestly covariant Aharonov-Bohm effect in terms of the 4D fields

  Physics (arXiv)

Summary: In this paper it is presented a manifestly covariant formulation of the Aharonov-Bohm (AB) phase difference for the magnetic AB effect . This covariant AB phase is written in terms of the Faraday 2-form F and using the decomposition of F in terms of the electric and magnetic fields as four-dimensional (4D) geometric quantities. It is shown that there is a static electric field outside a stationary solenoid with resistive conductor carrying steady current, which causes that the AB phase difference in the magnetic AB effect may be determined by the electric part of the covariant expression, i.e. by the local influence of the 4D electric field and not, as generally accepted,in terms of nonzero vector potential.

Tomislav Ivezic
2014-11-21

207

Triviality of the Aharonov-Bohm interaction in a spatially confining vacuum

  HEP - Theory (arXiv)

Summary: This paper explores long-range interactions between magnetically-charged excitations of the vacuum of the dual Landau-Ginzburg theory (DLGT) and the dual Abrikosov vortices present in the same vacuum. We show that, in the London limit of DLGT, the corresponding Aharonov-Bohm-type interactions possess such a coupling that the interactions reduce to a trivial factor of e^{2\\pi i (integer)}. The same analysis is done in the SU(N_c)-inspired [U(1)]^{N_c-1}-invariant DLGT, as well as in DLGT extended by a Chern-Simons term. It is furthermore explicitly shown that the Chern-Simons term leads to the appearance of knotted dual Abrikosov vortices.

Dmitri Antonov
2012-05-10

208

Levinson's theorem and higher degree traces for Aharonov-Bohm operators

  Mathematical Physics (arXiv)

Summary: We study Levinson type theorems for the family of Aharonov-Bohm models from different perspectives. The first one is purely analytical involving the explicit calculation of the wave-operators and allowing to determine precisely the various contributions to the left hand side of Levinson's theorem, namely those due to the scattering operator, the terms at 0-energy and at infinite energy. The second one is based on non-commutative topology revealing the topological nature of Levinson's theorem. We then include the parameters of the family into the topological description obtaining a new type of Levinson's theorem, a higher degree Levinson's theorem. In this context, the Chern number of a bundle defined by a family of projections on bound states is explicitly computed and related to the result of a 3-trace applied on the scattering part of the model.

J. Kellendonk; K. Pankrashkin; S. Richard
2010-12-15

209

Gaussian Curvature and Global effects : gravitational Aharonov-Bohm effect revisited

  CERN Preprints

Summary: Using the Gauss-Bonnet formula, integral of the Gaussian curvature over a 2-surface enclosed by a curve in the asymptotically flat region of a static spacetime was found to be a measure of a gravitational analogue of Aharonov-Bohm effect by Ford and Vilenkin in the linearized regime. Employing the 1+3 formulation of spacetime decomposition we study the same effect in the context of full Einstein field equations for stationary spacetimes. Applying our approach to static tube-like and cylindrical distributions of dust not only we recover their result but also obtain an extra term which is interpreted to be representing the classical version of the Colella-Overhauser-Werner effect (the COW experiment).

Nouri-Zonoz, M
2013-01-01

210

Transmission phase lapse in the non-Hermitian Aharonov-Bohm interferometer near the spectral singularity

  Quantum Physics (arXiv)

Summary: We study the effect of PT-symmetric imaginary potentials embedded in the two arms of an Aharonov-Bohm interferometer on the transmission phase by finding an exact solution for a concrete tight-binding system. It is observed that the spectral singularity always occurs at k=${\\pm}${\\pi}/2 for a wide range of fluxes and imaginary potentials. Critical behavior associated with the physics of the spectral singularity is also investigated. It is demonstrated that the quasi-spectral singularity corresponds to a transmission maximum and the transmission phase jumps abruptly by {\\pi} when the system is swept through this point. Moreover, We find that there exists a pulse-like phase lapse when the imaginary potential approaches the boundary value of the spectral singularity.

G. Zhang; X. Q. Li; X. Z. Zhang; Z. Song
2015-03-28

211

An Elementary Aharonov-Bohm System in Three Space Dimensions: Quantum Attraction With No Classical Force

  Quantum Physics (arXiv)

Summary: As a consequence of the Aharonov-Bohm effect, there is a quantum-induced attraction between a charged particle and a rigid, impenetrable hoop made from an arbitrarily thin tube containing a superconductor quantum of magnetic flux. This is remarkable because in classical physics there is no force between the two objects, and quantum-mechanical effects (associated with uncertainty principle energy) generally are repulsive rather than attractive. For an incident spinless charged particle in a P wave (in a configuration with total angular momentum zero) we verify a resonance just above threshold using the Kohn variational principle in its S-matrix form. Even if optimistic choices of parameters describing a model system with these properties turned out to be feasible, the temperature required to observe the resonance would be far lower than has yet been attained in the laboratory.

Alfred Scharff Goldhaber; Ryan Requist
2003-01-14

212

Aharonov-Bohm effect in the tunnelling of a quantum rotor in a linear Paul trap

  CERN Preprints

Summary: Quantum tunnelling is a common fundamental quantum-mechanical phenomenon that originates from the wave-like characteristics of quantum particles. Although the quantum-tunnelling effect was first observed 85 years ago, some questions regarding the dynamics of quantum tunnelling remain unresolved. Here, we realise a quantum-tunnelling system using two-dimensional ionic structures in a linear Paul trap. We demonstrate that the charged particles in this quantum-tunnelling system are coupled to the vector potential of a magnetic field throughout the entire process, even during quantum tunnelling, as indicated by the manifestation of the Aharonov-Bohm effect in this system. The tunnelling rate of the structures periodically depends on the strength of the magnetic field, whose period is the same as the magnetic-flux quantum $\\phi_0$ through the rotor [($0.99 \\pm 0.07)\\times \\phi_0$].

Noguchi, Atshushi; Toyoda, Kenji; Urabe, Shinji
2014-01-01

213

Aharonov-Bohm effect in the tunnelling of a quantum rotor in a linear Paul trap

  Quantum Physics (arXiv)

Summary: Quantum tunnelling is a common fundamental quantum-mechanical phenomenon that originates from the wave-like characteristics of quantum particles. Although the quantum-tunnelling effect was first observed 85 years ago, some questions regarding the dynamics of quantum tunnelling remain unresolved. Here, we realise a quantum-tunnelling system using two-dimensional ionic structures in a linear Paul trap. We demonstrate that the charged particles in this quantum-tunnelling system are coupled to the vector potential of a magnetic field throughout the entire process, even during quantum tunnelling, as indicated by the manifestation of the Aharonov-Bohm effect in this system. The tunnelling rate of the structures periodically depends on the strength of the magnetic field, whose period is the same as the magnetic-flux quantum $\\phi_0$ through the rotor [($0.99 \\pm 0.07)\\times \\phi_0$].

Atshushi Noguchi; Yutaka Shikano; Kenji Toyoda; Shinji Urabe
2014-05-20

214

Transmission phase lapse in the non-Hermitian Aharonov-Bohm interferometer near the spectral singularity

  Quantum Physics (arXiv)

Summary: We study the effect of PT-symmetric imaginary potentials embedded in the two arms of an Aharonov-Bohm interferometer on the transmission phase by finding an exact solution for a concrete tight-binding system. It is observed that the spectral singularity always occurs at k=${\\pm}${\\pi}/2 for a wide range of fluxes and imaginary potentials. Critical behavior associated with the physics of the spectral singularity is also investigated. It is demonstrated that the quasi-spectral singularity corresponds to a transmission maximum and the transmission phase jumps abruptly by {\\pi} when the system is swept through this point. Moreover, We find that there exists a pulse-like phase lapse when the imaginary potential approaches the boundary value of the spectral singularity.

G. Zhang; X. Q. Li; X. Z. Zhang; Z. Song
2014-12-25

215

Physical regularization for the spin-1/2 Aharonov-Bohm problem in conical space

  Mathematical Physics (arXiv)

Summary: We examine the bound state and scattering problem of a spin-one-half particle undergone to an Aharonov-Bohm potential in a conical space in the nonrelativistic limit. The crucial problem of the \\delta-function singularity coming from the Zeeman spin interaction with the magnetic flux tube is solved through the self-adjoint extension method. Using two different approaches already known in the literature, both based on the self-adjoint extension method, we obtain the self-adjoint extension parameter to the bound state and scattering scenarios in terms of the physics of the problem. It is shown that such a parameter is the same for both situations. The method is general and is suitable for any quantum system with a singular Hamiltonian that has bound and scattering states.

F. M. Andrade; E. O. Silva; M. Pereira
2012-02-23

216

Gaussian Curvature and Global effects : gravitational Aharonov-Bohm effect revisited

  Mathematical Physics (arXiv)

Summary: Using the Gauss-Bonnet formula, integral of the Gaussian curvature over a 2-surface enclosed by a curve in the asymptotically flat region of a static spacetime was found to be a measure of a gravitational analogue of Aharonov-Bohm effect by Ford and Vilenkin in the linearized regime. Employing the 1+3 formulation of spacetime decomposition we study the same effect in the context of full Einstein field equations for stationary spacetimes. Applying our approach to static tube-like and cylindrical distributions of dust not only we recover their result but also obtain an extra term which is interpreted to be representing the classical version of the Colella-Overhauser-Werner effect (the COW experiment).

M. Nouri-Zonoz; A. Parvizi
2013-06-08

217

Electromagnetism, local covariance, the Aharonov-Bohm effect and Gauss' law

  Mathematical Physics (arXiv)

Summary: We quantise the massless vector potential A of electromagnetism in the presence of a classical electromagnetic (background) current, j, in a generally covariant way on arbitrary globally hyperbolic spacetimes M. By carefully following general principles and procedures we clarify a number of topological issues. First we combine the interpretation of A as a connection on a principal U(1)-bundle with the perspective of general covariance to deduce a physical gauge equivalence relation, which is intimately related to the Aharonov-Bohm effect. By Peierls' method we subsequently find a Poisson bracket on the space of local, affine observables of the theory. This Poisson bracket is in general degenerate, leading to a quantum theory with non-local behaviour. We show that this non-local behaviour can be fully explained in terms of Gauss' law. Thus our analysis establishes a relationship, via the Poisson bracket, between the Aharonov-Bohm effect and Gauss' law (a relationship which seems to have gone unnoticed so far). Furthermore, we find a formula for the space of electric monopole charges in terms of the topology of the underlying spacetime. Because it costs little extra effort, we emphasise the cohomological perspective and derive our results for general p-form fields A (p < dim(M)), modulo exact fields. In conclusion we note that the theory is not locally covariant, in the sense of Brunetti-Fredenhagen-Verch. It is not possible to obtain such a theory by dividing out the centre of the algebras, nor is it physically desirable to do so. Instead we argue that electromagnetism forces us to weaken the axioms of the framework of local covariance, because the failure of locality is physically well-understood and should be accommodated.

Ko Sanders; Claudio Dappiaggi; Thomas-Paul Hack
2014-03-26

218

Electron vortex beams in a magnetic field: A new twist on Landau levels and Aharonov-Bohm states

  CERN Preprints

Summary: We examine the propagation of recently-discovered electron vortex beams in a longitudinal magnetic field. Both the Aharonov-Bohm configuration with a single flux line and the Landau case of a uniform magnetic field are considered. While stationary Aharonov-Bohm modes represent Bessel beams with field-dependent probability and current distributions, stationary Landau states manifest themselves as non-diffracting Laguerre-Gaussian beams. Furthermore, the Landau-state beams possess field- and vortex-dependent phases: (i) the Zeeman phase from coupling the quantized angular momentum to the magnetic field and (ii) the Gouy phase, known from optical Laguerre-Gaussian beams. Remarkably, together these phases determine the structure of Landau energy levels. This unified Zeeman-Landau-Gouy phase manifests itself in a nontrivial evolution of images formed by various superpositions of modes. We demonstrate that, depending on the chosen superposition, the image can rotate in a magnetic field with either Larmor, cyclotron...

Bliokh, Konstantin Y; Verbeeck, Jo; Nori, Franco
2012-01-01

219

Compactness in the d-bar Neumann problem, magnetic Schrodinger operators, and the Aharonov-Bohm effect

  Mathematical Physics (arXiv)

Summary: Compactness of the d-bar Neumann operator is studied for weakly pseudoconvex bounded Hartogs domains in two dimensions. A nonsmooth example is constructed in which condition (P) fails to hold, yet the Neumann operator is compact. The main result, in contrast, is that for smoothly bounded Hartogs domains, condition (P) of Catlin and Sibony is equivalent to compactness. The analyses of both compactness and condition (P) boil down to properties of the lowest eigenvalues of certain sequences of Schrodinger operators, with and without magnetic fields, parametrized by a Fourier variable resulting from the Hartogs symmetry. The nonsmooth counterexample is based on the Aharonov-Bohm phenomenon of quantum mechanics. For smooth domains, we prove that there always exists an exceptional sequence of Fourier variables for which the Aharonov-Bohm effect is quite weak. This sequence can be quite sparse, so that the failure of compactness is due to a rather subtle effect.

Michael Christ; Siqi Fu
2003-11-13

220

Nonlocal Phases of Local Quantum Mechanical Wavefunctions in Static and Time-Dependent Aharonov-Bohm Experiments

  CERN Preprints

Summary: We show that the standard Dirac phase factor is not the only solution of the gauge transformation equations. The full form of a general gauge function (that connects systems that move in different sets of scalar and vector potentials), apart from Dirac phases also contains terms of classical fields that act nonlocally (in spacetime) on the local solutions of the time-dependent Schr\\"odinger equation: the phases of wavefunctions in the Schr\\"odinger picture are affected nonlocally by spatially and temporally remote magnetic and electric fields, in ways that are fully explored. These contributions go beyond the usual Aharonov-Bohm effects (magnetic or electric). (i) Application to cases of particles passing through static magnetic or electric fields leads to cancellations of Aharonov-Bohm phases at the observation point; these are linked to behaviors at the semiclassical level (to the old Werner & Brill experimental observations, or their "electric analogs" - or to recent reports of Batelaan & Tonomura)...

Moulopoulos, Konstantinos
2010-01-01

221

How to test the gauge-invariant non-local quantum dynamics of the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The gauge invariant non local quantum dynamics of the Aharonov-Bohm effect can be tested experimentally by measuring the instantaneous shift of the velocity distribution occurring when the particle passes by the flux line. It is shown that in relativistic quantum theory it is possible to measure the instantaneous velocity with accuracy sufficient to detect the change of the velocity distribution. In non relativistic quantum theory the instantaneous velocity can be measured to any desired accuracy.

T. Kaufherr
2014-11-11

222

VOLUME 87, NUMBER 4 P H Y S I C A L R E V I E W L E T T E R S 23 JULY 2001 Nonlinear Aharonov-Bohm Scattering by Optical Vortices

  Physics Websites

Summary: Physics Group, Research School of Physical Sciences and Engineering, The Australian National University. This phenomenon is known these days as the Aharonov-Bohm effect [1], and it was shown to have a more general geo with the Aharonov-Bohm effect, allowing one to observe directly the macroscopic aspects of the geo- metrical phases


223

On the causality of electrodynamics and the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: This paper presents a \\emph{non-instant field model} for electrodynamics that permits a causal explanation of the \\emph{Aharonov-Bohm effect} and a \\emph{covariant quantization} of the respective Maxwell equations via the \\emph{Gupta-Bleuler method}. Our model satisfies the following \\emph{correspondence principle}: if $A^\\mu$, $\\vE$, $\\vB$ denote the four potential, the electric field and the magnetic field of the non-instant field model, then the respective classical quantities are $\\A[A^\\mu]$, $\\A[\\vE]$, $\\A[\\vB]$, where $\\A$ is a covariant time averaging operator. Here $\\A[A^\\mu]$ is interpreted as the best possible measurement of the four potential $A^\\mu$. Although the Lorentz condition is not satisfied for $A^\\mu$, it is satisfied for $\\A[A^\\mu]$. The latter fact means that the Lorentz condition does not hold for the quantized field but for its expectation value (cf. \\emph{Gupta-Bleuler method} of quantization). Finally, we derive the energy conservation law of our field model and show that the field energy is quantized.

Richard Kowar
2011-11-24

224

Precession and interference in the Aharonov-Casher and scalar Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The ideal scalar Aharonov-Bohm (SAB) and Aharonov-Casher (AC) effect involve a magnetic dipole pointing in a certain fixed direction: along a purely time dependent magnetic field in the SAB case and perpendicular to a planar static electric field in the AC case. We extend these effects to arbitrary direction of the magnetic dipole. The precise conditions for having nondispersive precession and interference effects in these generalized set ups are delineated both classically and quantally. Under these conditions the dipole is affected by a nonvanishing torque that causes pure precession around the directions defined by the ideal set ups. It is shown that the precession angles are in the quantal case linearly related to the ideal phase differences, and that the nonideal phase differences are nonlinearly related to the ideal phase differences. It is argued that the latter nonlinearity is due the appearance of a geometric phase associated with the nontrivial spin path. It is further demonstrated that the spatial force vanishes in all cases except in the classical treatment of the nonideal AC set up, where the occurring force has to be compensated by the experimental arrangement. Finally, for a closed space-time loop the local precession effects can be inferred from the interference pattern characterized by the nonideal phase differences and the visibilities. It is argued that this makes it natural to regard SAB and AC as essentially local and nontopological effects.

Philipp Hyllus; Erik Sjöqvist
2002-10-10

225

Transport, Aharonov-Bohm, and Topological Effects in Graphene Molecular Junctions and Graphene Nanorings

  Nuclear Theory (arXiv)

Summary: The unique ultra-relativistic, massless, nature of electron states in two-dimensional extended graphene sheets, brought about by the honeycomb lattice arrangement of carbon atoms in two-dimensions, provides ingress to explorations of fundamental physical phenomena in graphene nanostructures. Here we explore the emergence of new behavior of electrons in atomically precise segmented graphene nanoribbons (GNRs) and graphene rings with the use of tight-binding calculations, non-equilibrium Green's function transport theory, and a newly developed Dirac continuum model that absorbs the valence-to-conductance energy gaps as position-dependent masses, including topological-in-origin mass-barriers at the contacts between segments. Through transport investigations in variable-width segmented GNRs with armchair, zigzag, and mixed edge terminations we uncover development of new Fabry-Perot-like interference patterns in segmented GNRs, a crossover from the ultra-relativistic massless regime, characteristic of extended graphene systems, to a massive relativistic behavior in narrow armchair GNRs, and the emergence of nonrelativistic behavior in zigzag-terminated GNRs. Evaluation of the electronic states in a polygonal graphene nanoring under the influence of an applied magnetic field in the Aharonov-Bohm regime, and their analysis with the use of a relativistic quantum-field theoretical model, unveils development of a topological-in-origin zero-energy soliton state and charge fractionization. These results provide a unifying framework for analysis of electronic states, coherent transport phenomena, and the interpretation of forthcoming experiments in segmented graphene nanoribbons and polygonal rings.

Constantine Yannouleas; Igor Romanovsky; Uzi Landman
2015-02-16

226

Aharonov-Bohm effect in relativistic and nonrelativistic 2D electron gas: a comparative study

  HEP - Phenomenology (arXiv)

Summary: We carry out a comparative study of electronic properties of 2D electron gas (2DEG) in a magnetic field of an infinitesimally thin solenoid with relativistic dispersion as in graphene and quadratic dispersion as in semiconducting heterostructures. The problem of ambiguity of the zero mode solutions of the Dirac equation is treated by considering of a finite radius flux tube which allows to select unique solutions associated with each $\\mathbf{K}$ point of graphene's Brillouin zone. Then this radius is allowed to go to zero. On the base of the obtained in this case analytical solutions in the Aharonov-Bohm potential the local and total density of states (DOS) are calculated. It is shown that in the case of graphene there is an excess of LDOS near the vortex, while in 2DEG the LDOS is depleted. This results in excess of the induced by the vortex DOS in graphene and in its depletion in 2DEG. We discuss the application of the results for the local density of states for the scanning tunneling spectroscopy done on graphene.

A. O. Slobodeniuk; S. G. Sharapov; V. M. Loktev
2010-08-21

227

Creation of planar charged fermions in Coulomb and Aharonov-Bohm potentials

  HEP - Phenomenology (arXiv)

Summary: The creation of charged fermions from the vacuum by a Coulomb field in the presence of an Aharonov--Bohm (AB) potential are studied in 2+1 dimensions. The process is governed by a (singular) Dirac Hamiltonian that requires the supplementary definition in order for it to be treated as a self-adjoint quantum-mechanical operator. By constructing a one-parameter self-adjoint extension of the Dirac Hamiltonian, specified by boundary conditions, we describe the (virtual bound) quasistationary states with "complex energy" emerging in an attractive Coulomb potential, derive for the first time, complex equations (depending upon the electron spin and the extension parameter) for the quasistationary state "complex energy". The constructed self-adjoint Dirac Hamiltonians in Coulomb and AB potentials are applied to provide a correct description to the low-energy electron excitations, as well as the creation of charged quasiparticles from the vacuum in graphene by the Coulomb impurity in the presence of AB potential. It is shown that the strong Coulomb field can create charged fermions for some range of the extension parameter.

V. R. Khalilov
2013-09-09

228

Effect of vacuum polarization of charged massive fermions in an Aharonov--Bohm field

  Quantum Physics (arXiv)

Summary: The effect of vacuum polarization of charged massive fermions in an Aharonov-Bohm (AB) potential in 2+1 dimensions is investigated. The causal Green's function of the Dirac equation with the AB potential is represented via the regular and irregular solutions of the two-dimensional radial Dirac equation. It is shown that the vacuum current density contains the contribution from free filled states of the negative energy continuum as well as that from a bound unfilled state, which can emerge in the above background due to the interaction of the fermion spin magnetic moment with the AB magnetic field while the induced charge density contains only the contribution from the bound state. The expressions for the vacuum charge and induced current densities are obtained (recovered for massless fermions) for the graphene in the field of infinitesimally thin solenoid perpendicular to the plane of a sample. We also find the bound state energy as a function of magnetic flux, fermion spin and the radius of solenoid as well as discuss the role of the so-called self-adjoint extension parameter and determine it in terms of the physics of the problem.

V. R. Khalilov
2014-07-16

229

Interference between two independent electrons: observation of two-particle Aharonov-Bohm interference

  Quantum Physics (arXiv)

Summary: Very much like the ubiquitous quantum interference of a single particle with itself, quantum interference of two independent, but indistinguishable, particles is also possible. This interference is a direct result of quantum exchange statistics, however, it is observed only in the joint probability to find the particles in two separated detectors. Here we report the first observation of such interference fringes between two independent and non-interacting electrons in an interferometer proposed by Yurke et al. and Samuelsson et al. Our experiment resembles the "Hanbury Brown and Twiss" (HBT) experiment, which was performed with classical waves. In the experiment, two independent and mutually incoherent electron beams were each partitioned into two trajectories. The combined four trajectories enclosed an Aharonov-Bohm (AB) flux (but not the two trajectories of a single electron). While individual currents were found to be independent of the AB flux, as expected, the cross-correlation between current fluctuations in two opposite points across the device exhibited strong AB oscillations. This is a direct signature of orbital entanglement between two electrons even though they never interact with each other.

I. Neder; N. Ofek; Y. Chung; M. Heiblum; D. Mahalu; V. Umansky
2007-05-01

230

NonAbelian Vortices, Large Winding Limits and Aharonov-Bohm Effects

  HEP - Theory (arXiv)

Summary: Remarkable simplification arises from considering vortex equations in the large winding limit. This was recently used in [1] to display all sorts of vortex zeromodes, the orientational, translational, fermionic as well as semi-local, and to relate them to the apparently distinct phenomena of the Nielsen-Olesen-Ambjorn magnetic instabilities. Here we extend these analyses to more general types of BPS nonAbelian vortices, taking as a prototype a system with gauged U(1) x SU(N) x SU(N) symmetry where the VEV of charged scalar fields in the bifundamental representation breaks the symmetry to SU(N)_{l+r} . The presence of the massless SU(N)_{l+r} gauge fields in 4D bulk introduces all sorts of non-local, topological phenomena such as the nonAbelian Aharonov-Bohm effects, which in the theory with global SU(N)_r group (g_r=0) are washed away by the strongly fluctuating orientational zeromodes in the worldsheet. Physics changes qualitatively at the moment the right gauge coupling constant g_r is turned on.

Stefano Bolognesi; Chandrasekhar Chatterjee; Kenichi Konishi
2015-03-20

231

Aharonov-Bohm interference in the presence of metallic mesoscopic cylinders

  Quantum Physics (arXiv)

Summary: This work studies the interference of electrons in the presence of a line of magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low temperature. It is found that, while there is a supplementary phase contribution from each electron of the mesoscopic cylinder, the sum of these individual supplementary phases is equal to zero, so that the presence of a normal-conducting mesoscopic ring at low temperature does not change the Aharonov-Bohm interference pattern of the incident electron. It is shown that it is not possible to ascertain by experimental observation that the shielding electrons have responded to the field of an incident electron, and at the same time to preserve the interference pattern of the incident electron. It is also shown that the measuring of the transient magnetic field in the region between the two paths of an electron interference experiment with an accuracy at least equal to the magnetic field of the incident electron generates a phase uncertainty which destroys the interference pattern.

Silviu Olariu
1997-02-10

232

Filtering and analyzing mobile qubit information via Rashba-Dresselhaus-Aharonov-Bohm interferometers

  Quantum Physics (arXiv)

Summary: Spin-1/2 electrons are scattered through one or two diamond-like loops, made of quantum dots connected by one-dimensional wires, and subject to both an Aharonov-Bohm flux and (Rashba and Dresselhaus) spin-orbit interactions. With some symmetry between the two branches of each diamond, and with appropriate tuning of the electric and magnetic fields (or of the diamond shapes) this device completely blocks electrons with one polarization, and allows only electrons with the opposite polarization to be transmitted. The directions of these polarizations are tunable by these fields, and do not depend on the energy of the scattered electrons. For each range of fields one can tune the site and bond energies of the device so that the transmission of the fully polarized electrons is close to unity. Thus, these devices perform as ideal spin filters, and these electrons can be viewed as mobile qubits; the device writes definite quantum information on the spinors of the outgoing electrons. The device can also read the information written on incoming polarized electrons: the charge transmission through the device contains full information on this polarization. The double-diamond device can also act as a realization of the Datta-Das spin field-effect transistor.

Amnon Aharony; Yasuhiro Tokura; Guy Z. Cohen; Ora Entin-Wohlman; Shingo Katsumoto
2011-03-11

233

Filtering and analyzing mobile qubit information via Rashba-Dresselhaus-Aharonov-Bohm interferometers

  CERN Preprints

Summary: Spin-1/2 electrons are scattered through one or two diamond-like loops, made of quantum dots connected by one-dimensional wires, and subject to both an Aharonov-Bohm flux and (Rashba and Dresselhaus) spin-orbit interactions. With some symmetry between the two branches of each diamond, and with appropriate tuning of the electric and magnetic fields (or of the diamond shapes) this device completely blocks electrons with one polarization, and allows only electrons with the opposite polarization to be transmitted. The directions of these polarizations are tunable by these fields, and do not depend on the energy of the scattered electrons. For each range of fields one can tune the site and bond energies of the device so that the transmission of the fully polarized electrons is close to unity. Thus, these devices perform as ideal spin filters, and these electrons can be viewed as mobile qubits; the device writes definite quantum information on the spinors of the outgoing electrons. The device can also read the info...

Aharony, Amnon; Cohen, Guy Z; Entin-Wohlman, Ora; Katsumoto, Shingo
2011-01-01

234

A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms

  Quantum Physics (arXiv)

Summary: Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a "hairline" solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

Ming-Xia Huo; Nie Wei; David A. W. Hutchinson; Leong Chuan Kwek
2014-08-11

235

On the relation between the Feynman paradox and Aharonov-Bohm effects

  Quantum Physics (arXiv)

Summary: The magnetic Aharonov-Bohm (A-B) effect occurs when a point charge interacts with a line of magnetic flux, while its dual, the Aharonov-Casher (A-C) effect, occurs when a magnetic moment interacts with a line of charge. For the two interacting parts of these physical systems, the equations of motion are discussed in this paper. The generally accepted claim is that both parts of these systems do not accelerate, while Boyer has claimed that both parts of these systems do accelerate. Using the Euler-Lagrange equations we predict that in the case of unconstrained motion only one part of each system accelerates, while momentum remains conserved. This prediction requires a time dependent electromagnetic momentum. For our analysis of unconstrained motion the A-B effects are then examples of the Feynman paradox. In the case of constrained motion, the Euler-Lagrange equations give no forces in agreement with the generally accepted analysis. The quantum mechanical A-B and A-C phase shifts are independent of the treatment of constraint. Nevertheless, experimental testing of the above ideas and further understanding of A-B effects which is central to both quantum mechanics and electromagnetism may be possible.

Scot McGregor; Ryan Hotovy; Adam Caprez; Herman Batelaan
2012-07-06

236

Charge Detection in a Closed-Loop Aharonov-Bohm Interferometer

  Quantum Physics (arXiv)

Summary: We report on a study of complementarity in a two-terminal "closed-loop" Aharonov-Bohm interferometer. In this interferometer, the simple picture of two-path interference cannot be applied. We introduce a nearby quantum point contact to detect the electron in a quantum dot inserted in the interferometer. We found that charge detection reduces but does not completely suppress the interference even in the limit of perfect detection. We attribute this phenomenon to the unique nature of the closed-loop interferometer. That is, the closed-loop interferometer cannot be simply regarded as a two-path interferometer because of multiple reflections of electrons. As a result, there exist indistinguishable paths of the electron in the interferometer and the interference survives even in the limit of perfect charge detection. This implies that charge detection is not equivalent to path detection in a closed-loop interferometer. We also discuss the phase rigidity of the transmission probability for a two-terminal conductor in the presence of a detector.

Gyong Luck Khym; Kicheon Kang
2006-06-15

237

Classical Interaction of a Magnet and a Point Charge: The Classical Electromagnetic Forces Responsible for the Aharonov-Bohm Phase Shift

  CERN Preprints

Summary: A new classical electromagnetic analysis is presented suggesting that the Aharonov-Bohm phase shift is overwhelmingly likely to arise from a classical lag effect based upon classical electromagnetic forces. The analysis makes use of several aspects of classical electromagnetic theory which are unfamiliar to most physicists, including the Darwin Lagrangian, acceleration-based electric fields, internal electromagnetic momentum in a magnet, and a magnet model involving at least three mutually-interacting particles. Only when the acceleration-based electric forces acting on the passing charge are included do we find consistency with all the relativistic conservation laws: energy, linear momentum, angular momentum, and constant center-of-mass velocity. The electric forces on the passing charge lead to a lag effect which accounts quantitatively for the Aharonov-Bohm phase shift. Thus the classical analysis strongly suggests that the Aharonov-Bohm phase shift (observed when electrons pass a long solenoid which corre...

Boyer, Timothy H
2014-01-01

238

Dephasing in an Aharonov-Bohm interferometer containing a lateral double quantum dot induced by coupling with a quantum dot charge sensor

  Quantum Physics (arXiv)

Summary: We theoretically investigated the dephasing in an Aharonov-Bohm interferometer containing a lateral double quantum dot induced by coupling with a quantum dot charge sensor. We employed the interpolative 2nd-order perturbation theory to include the charge sensing Coulomb interaction. It is shown that the visibility of the Aharonov-Bohm oscillation of the linear conductance decreases monotonically as the sensing Coulomb interaction increases. In particular, for a weak sensing interaction regime, the visibility decreases parabolically, and it behaves linearly for a strong sensing interaction regime.

T. Kubo; Y. Tokura; S. Tarucha
2010-05-12

239

Nonlocal Phases of Local Quantum Mechanical Wavefunctions in Static and Time-Dependent Aharonov-Bohm Experiments

  Mathematical Physics (arXiv)

Summary: We show that the standard Dirac phase factor is not the only solution of the gauge transformation equations. The full form of a general gauge function (that connects systems that move in different sets of scalar and vector potentials), apart from Dirac phases also contains terms of classical fields that act nonlocally (in spacetime) on the local solutions of the time-dependent Schr\\"odinger equation: the phases of wavefunctions in the Schr\\"odinger picture are affected nonlocally by spatially and temporally remote magnetic and electric fields, in ways that are fully explored. These contributions go beyond the usual Aharonov-Bohm effects (magnetic or electric). (i) Application to cases of particles passing through static magnetic or electric fields leads to cancellations of Aharonov-Bohm phases at the observation point; these are linked to behaviors at the semiclassical level (to the old Werner & Brill experimental observations, or their "electric analogs" - or to recent reports of Batelaan & Tonomura) but are shown to be far more general (true not only for narrow wavepackets but also for completely delocalized quantum states). By using these cancellations, certain previously unnoticed sign-errors in the literature are corrected. (ii) Application to time-dependent situations provides a remedy for erroneous results in the literature (on improper uses of Dirac phase factors) and leads to phases that contain an Aharonov-Bohm part and a field-nonlocal part: their competition is shown to recover Relativistic Causality in earlier "paradoxes" (such as the van Kampen thought-experiment), while a more general consideration indicates that the temporal nonlocalities found here demonstrate in part a causal propagation of phases of quantum mechanical wavefunctions in the Schr\\"odinger picture. This may open a direct way to address time-dependent double-slit experiments and the associated causal issues

Konstantinos Moulopoulos
2010-09-17

240

Elastic scattering and bound states in the Aharonov-Bohm potential superimposed by an attractive $?^{-2}$ potential

  Quantum Physics (arXiv)

Summary: We consider the elastic scattering and bound states of charged quantum particles moving in the Aharonov-Bohm and an attractive $\\rho^{-2}$ potential in a partial wave approach. Radial solutions of the stationary Schr\\"{o}dinger equation are specified in such a way that the Hamiltonian of the problem is self-adjoint. It is shown that they are not uniquely fixed but depend on open parameters. The related physical consequences are discussed. The scattering cross section is calculated and the energy spectrum of bound states is obtained.

Juergen Audretsch; Vladimir D. Skarzhinsky; Boris L. Voronov
2000-11-30

241

Off-Diagonal Long-Range Order, Restricted Gauge Transformations, and Aharonov-Bohm Effect in Conductors

  HEP - Theory (arXiv)

Summary: The Hamiltonian describing a conductor surrounding an external magnetic field contains a nonvanishing vector potential in the volume accessible to the electrons and nuclei of which the conductor is made. That vector potential cannot be removed by a gauge transformation. Nevertheless, a macroscopic normal conductor can experience no Aharonov-Bohm effect. That is proved by assuming only that a normal conductor lacks off-diagonal long-range order (ODLRO). Then by restricting the Hilbert space to density matrices which lack ODLRO, it is possible to introduce a restricted gauge transformation that removes the interaction of the conductor with the vector potential.

Murray Peshkin
1995-10-20

242

Partial Wave Analysis of Scattering with Nonlocal Aharonov-Bohm Effect and Anomalous Cross Section induced by Quantum Interference

  Quantum Physics (arXiv)

Summary: Partial wave theory of a three dmensional scattering problem for an arbitray short range potential and a nonlocal Aharonov-Bohm magnetic flux is established. The scattering process of a ``hard shere'' like potential and the magnetic flux is examined. An anomalous total cross section is revealed at the specific quantized magnetic flux at low energy which helps explain the composite fermion and boson model in the fractional quantum Hall effect. Since the nonlocal quantum interference of magnetic flux on the charged particles is universal, the nonlocal effect is expected to appear in quite general potential system and will be useful in understanding some other phenomena in mesoscopic phyiscs.

De-Hone Lin
2004-06-09

243

Perturbative Study of Bremsstrahlung and Pair-Production by Spin-1/2 Particles in the Aharonov-Bohm Potential

  HEP - Theory (arXiv)

Summary: In the presence of an external Aharonov-Bohm potential, we investigate the two QED processes of the emission of a bremsstrahlung photon by an electron, and the production of an electron-positron pair by a single photon. Calculations are carried out using the Born approximation within the framework of covariant perturbation theory to lowest non-vanishing order in \\alpha. The matrix element for each process is derived, and the corresponding differential cross-section is calculated. In the non-relativistic limit, the resulting angular and spectral distributions and some polarization properties are considered, and compared to results of previous works.

U. A. al-Binni; M. S. Shikakhwa
2004-05-24

244

Aharonov-Bohm effect on AdS_2 and nonlinear supersymmetry of reflectionless Poschl-Teller system

  Mathematical Physics (arXiv)

Summary: We explain the origin and the nature of a special nonlinear supersymmetry of a reflectionless Poschl-Teller system by the Aharonov-Bohm effect for a nonrelativistic particle on the AdS_2. A key role in the supersymmetric structure appearing after reduction by a compact generator of the AdS_2 isometry is shown to be played by the discrete symmetries related to the space and time reflections in the ambient Minkowski space. We also observe that a correspondence between the two quantum non-relativistic systems is somewhat of the AdS/CFT holography nature.

Francisco Correa; Vit Jakubsky; Mikhail S. Plyushchay
2009-03-29

245

High-Velocity Estimates for the Scattering Operator and Aharonov-Bohm Effect in Three Dimensions

  Mathematical Physics (arXiv)

Summary: We obtain high-velocity estimates with error bounds for the scattering operator of the Schr\\"odinger equation in three dimensions with electromagnetic potentials in the exterior of bounded obstacles that are handlebodies. A particular case is a finite number of tori. We prove our results with time-dependent methods. We consider high-velocity estimates where the direction of the velocity of the incoming electrons is kept fixed as its absolute value goes to infinity. In the case of one torus our results give a rigorous proof that quantum mechanics predicts the interference patterns observed in the fundamental experiments of Tonomura et al. that gave a conclusive evidence of the existence of the Aharonov-Bohm effect using a toroidal magnet. We give a method for the reconstruction of the flux of the magnetic field over a cross-section of the torus modulo $2\\pi$. Equivalently, we determine modulo $2\\pi$ the difference in phase for two electrons that travel to infinity, when one goes inside the hole and the other outside it. For this purpose we only need the high-velocity limit of the scattering operator for one direction of the velocity of the incoming electrons. When there are several tori -or more generally handlebodies- the information that we obtain in the fluxes, and on the difference of phases, depends on the relative position of the tori and on the direction of the velocities when we take the high-velocity limit of the incoming electrons. For some locations of the tori we can determine all the fluxes modulo 2$\\pi$ by taking the high-velocity limit in only one direction. We also give a method for the unique reconstruction of the electric potential and the magnetic field outside the handlebodies from the high-velocity limit of the scattering operator.

Miguel Ballesteros; Ricardo Weder
2007-11-16

246

Electron vortex beams in a magnetic field: A new twist on Landau levels and Aharonov-Bohm states

  Quantum Physics (arXiv)

Summary: We examine the propagation of the recently-discovered electron vortex beams in a longitudinal magnetic field. We consider both the Aharonov-Bohm configuration with a single flux line and the Landau case of a uniform magnetic field. While stationary Aharonov-Bohm modes represent Bessel beams with flux- and vortex-dependent probability distributions, stationary Landau states manifest themselves as non-diffracting Laguerre-Gaussian beams. Furthermore, the Landau-state beams possess field- and vortex-dependent phases: (i) the Zeeman phase from coupling the quantized angular momentum to the magnetic field and (ii) the Gouy phase, known from optical Laguerre-Gaussian beams. Remarkably, together these phases determine the structure of Landau energy levels. This unified Zeeman-Landau-Gouy phase manifests itself in a nontrivial evolution of images formed by various superpositions of modes. We demonstrate that, depending on the chosen superposition, the image can rotate in a magnetic field with either (i) Larmor, (ii) cyclotron (double-Larmor), or (iii) zero frequency. At the same time, its centroid always follows the classical cyclotron trajectory, in agreement with the Ehrenfest theorem. Remarkably, the non-rotating superpositions reproduce stable multi-vortex configurations that appear in rotating superfluids. Our results open up an avenue for the direct electron-microscopy observation of fundamental properties of free quantum electron states in magnetic fields.

Konstantin Y. Bliokh; Peter Schattschneider; Jo Verbeeck; Franco Nori
2012-10-02

247

On the spin-1/2 Aharonov-Bohm problem in conical space: bound states, scattering and helicity nonconservation

  Mathematical Physics (arXiv)

Summary: In this work the bound state and scattering problems for a spin-1/2 particle undergone to an Aharonov-Bohm potential in a conical space in the nonrelativistic limit are considered. The presence of a \\delta-function singularity, which comes from the Zeeman spin interaction with the magnetic flux tube, is addressed by the self-adjoint extension method. One of the advantages of the present approach is the determination of the self-adjoint extension parameter in terms of physics of the problem. Expressions for the energy bound states, phase-shift and $S$ matrix are determined in terms of the self-adjoint extension parameter, which is explicitly determined in terms of the parameters of the problem. The relation between the bound state and zero modes and the failure of helicity conservation in the scattering problem and its relation with the gyromagnetic ratio $g$ are discussed. Also, as an application, we consider the spin-1/2 Aharonov-Bohm problem in conical space plus a two-dimensional isotropic harmonic oscillator.

F. M. Andrade; E. O. Silva; M. Pereira
2013-10-23

248

Phase rigidity and h/2e oscillations in a single-ring Aharonov-Bohm experiment A. Yacoby, R. Schuster, and M. Heiblum

  Physics Websites

Summary: Phase rigidity and h/2e oscillations in a single-ring Aharonov-Bohm experiment A. Yacoby, R-Bohm AB ring. The observed phase rigidity of the AB conductance oscillations is theoretically explained completely the con- ductance of a single AB ring. In a recent interference experiment 1 we devised a method

Heiblum, Mordehai "Moty"

249

Aharonov-Bohm effect in the non-Abelian quantum Hall fluid Lachezar S. Georgiev1 and Michael R. Geller2

  Physics Websites

Summary: . Geller2 1Institute for Nuclear Research and Nuclear Energy, 72 Tsarigradsko Chaussee, 1784 Sofia of this state in an Aharonov-Bohm geometry. While not probing statistics directly, the measurements proposed in a partially occupied Landau level with complex coordinates zi, where the first term is the Pfaff- ian

Geller, Michael R.

250

Dynamics of One-Dimensional Bose Liquids: Andreev-Like Reflection at Y Junctions and the Absence of the Aharonov-Bohm Effect

  Materials Science Websites

Summary: ) effect in the ring type interferometer, which consists of two Y-shaped junctions as in Fig. 2 of the Aharonov-Bohm Effect Akiyuki Tokuno,1,2 Masaki Oshikawa,1 and Eugene Demler3 1 Institute for Solid State liquids of interacting ultracold atoms in the Y-shaped potential when each branch is filled with atoms. We

Demler, Eugene

251

Mesoscopic photovoltaic effect in GaAs/Ga1-xAlxAs Aharonov-Bohm rings L. Angers, A. Chepelianskii, R. Deblock, B. Reulet, and H. Bouchiat

  Physics Websites

Summary: Mesoscopic photovoltaic effect in GaAs/Ga1-xAlxAs Aharonov-Bohm rings L. Angers, A. Chepelianskii specific dc voltage. We have investigated this photovoltaic PV effect on GaAs/Ga1-xAlxAs Aharonov is generally done by measuring the dc induced signal sometimes called photovoltaic effect which has also given

Shepelyansky, Dima

252

Quantum geometric phase in Majorana's stellar representation: Mapping onto a many-body Aharonov-Bohm phase

  Quantum Physics (arXiv)

Summary: The (Berry-Aharonov-Anandan) geometric phase acquired during a cyclic quantum evolution of finite-dimensional quantum systems is studied. It is shown that a pure quantum state in a (2J+1)-dimensional Hilbert space (or, equivalently, of a spin-J system) can be mapped onto the partition function of a gas of independent Dirac strings moving on a sphere and subject to the Coulomb repulsion of 2J fixed test charges (the Majorana stars) characterizing the quantum state. The geometric phase may be viewed as the Aharonov-Bohm phase acquired by the Majorana stars as they move through the gas of Dirac strings. Expressions for the geometric connection and curvature, for the metric tensor, as well as for the multipole moments (dipole, quadrupole, etc.), are given in terms of the Majorana stars. Finally, the geometric formulation of the quantum dynamics is presented and its application to systems with exotic ordering such as spin nematics is outlined.

Patrick Bruno
2012-06-13

253

Partial wave Analysis of the First Order Born Amplitude of a Dirac Particle in an Aharonov-Bohm Potential

  Quantum Physics (arXiv)

Summary: A partial wave analysis using the basis of the total angular momentum operator J_3 is carried out for the first order Born amplitude of a Dirac particle in an Aharonov-Bohm (AB)potential. It is demonstrated that the s-partial wave contributes to the scattering amplitude in contrast to the case with scalar non-relativistic particles.We suggest that this explains the fact that the first order Born amplitude of a Dirac particle coincides with the exact amplitude expanded to the same order, where it does not for a scalar particle. An interesting algebra involving the Dirac velocity operator and the angular observables is discovered and its consequences are exploited.

M. S. Shikakhwa; N. K. Pak
2003-02-20

254

Finite Difference-Time Domain solution of the Dirac equation and the dynamics of the Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The time-dependent Dirac equation is solved using the three-dimensional Finite Difference-Time Domain (FDTD) method. The dynamics of the electron wave packet in a vector potential is studied in the arrangements associated with the Aharonov-Bohm effect. The solution of the Dirac equation showed a change in the velocity of the electron wave packet even in a region where no forces acted on the electron. The solution of the Dirac equation agreed with the prediction of classical dynamics under the assumption that the dynamics was defined by the conservation of generalized or canonical momentum. It was also shown that in the case when the magnetic field was not zero, the conservation of generalized or canonical momentum was equivalent to the action of the Lorentz force.

Neven Simicevic
2009-09-14

255

Dirac Particle in an Aharonov-Bohm Potential: The Structure of the First Order S-matrix

  Mathematical Physics (arXiv)

Summary: The structure of the interaction Hamiltonian in the first order $S-$matrix element of a Dirac particle in an Aharonov-Bohm (AB) field is analyzed and shown to have interesting algebraic properties. It is demonstrated that as a consequence of these properties, this interaction Hamiltonian splits both the incident and outgoing waves in the the first order $S-$matrix into their $\\frac{\\Sigma_3}{2}-$components (eigenstates of the third component of the spin). The matrix element can then be viewed as the sum of two transitions taking place in these two channels of the spin. At the level of partial waves, each partial wave of the conserved total angular momentum is split into two partial waves of the orbital angular momentum in a manner consistent with the conservation of the total angular momentum quantum number.

M. S. Shikakhwa
2006-08-05

256

On the spectrum of the Schrodinger Operator with Aharonov-Bohm Magnetic Field in quantum waveguide with Neumann window

  Mathematical Physics (arXiv)

Summary: In a previous study \\cite{n} we investigate the bound states of the Hamiltonian describing a quantum particle living on three dimensional straight strip of width $d$. We impose the Neumann boundary condition on a disc window of radius $a$ and Dirichlet boundary conditions on the remained part of the boundary of the strip. We proved that such system exhibits discrete eigenvalues below the essential spectrum for any $a>0$. In the present work we study the effect of a magnetic filed of Aharonov-Bohm type when the magnetic field is turned on this system. Precisely we prove that in the presence of such magnetic filed there is some critical values of $a_0>0$, for which we have absence of the discrete spectrum for $\\displaystyle 0<\\frac{a}{d}

H. Najar; M. Rayssi
2012-11-10

257

Barotropic Magnetohydrodynamics as a Four Function Field Theory with Non-Trivial Topology and Aharonov-Bohm Effects

  Quantum Physics (arXiv)

Summary: Variational principles for magnetohydrodynamics were introduced by previous authors both in Lagrangian and Eulerian form. In previous works [1] Yahalom & Lynden-Bell and later Yahalom [2] introduced a simpler Eulerian variational principle from which all the relevant equations of Magnetohydrodynamics can be derived. The variational principles were given in terms of four independent functions for non-stationary flows and three independent functions for stationary flows. This is less than the seven variables which appear in the standard equations of magnetohydrodynamics which are the magnetic field, the velocity field and the density . In the case that the magnetohydrodynamic flow has a non trivial topology such as when the magnetic lines are knotted or magnetic and stream lines are knotted, some of the functions appearing in the Lagrangian are non-single valued. Those functions play the same rule as the phase in the Aharonov-Bohm celebrated effect [3].

Asher Yahalom
2010-05-21

258

Spin polarisation by external magnetic fields, Aharonov-Bohm flux strings, and chiral symmetry breaking in QED$_3$

  HEP - Theory (arXiv)

Summary: In the first part, the induced vacuum spin around an Aharonov-Bohm flux string in massless three-dimensional QED is computed explicitly and the result is shown to agree with a general index theorem. A previous observation in the literature, that the presence of induced vacuum quantum numbers which are not periodic in the flux make an integral-flux AB string visible, is reinforced. In the second part, a recent discussion of chiral symmetry breaking by external magnetic fields in parity invariant QED$_3$ and its relation to the induced spin in parity non-invariant QED$_3$ is further elaborated. Finally other vacuum polarisation effects around flux tubes in different variants of QED, in three and four dimensions are mentioned.

Rajesh Parwani
1995-06-09

259

Reduction by symmetries in singular quantum-mechanical problems: general scheme and application to Aharonov-Bohm model

  Mathematical Physics (arXiv)

Summary: We develop a general technique for finding self-adjoint extensions of a symmetric operator that respect a given set of its symmetries. Problems of this type naturally arise when considering two- and three-dimensional Schr\\"odinger operators with singular potentials. The approach is based on constructing a unitary transformation diagonalizing the symmetries and reducing the initial operator to the direct integral of a suitable family of partial operators. We prove that symmetry preserving self-adjoint extensions of the initial operator are in a one-to-one correspondence with measurable families of self-adjoint extensions of partial operators obtained by reduction. The general scheme is applied to the three-dimensional Aharonov-Bohm Hamiltonian describing the electron in the magnetic field of an infinitely thin solenoid. We construct all self-adjoint extensions of this Hamiltonian, invariant under translations along the solenoid and rotations around it, and explicitly find their eigenfunction expansions.

A. G. Smirnov
2014-12-15

260

Linear Dynamic Polarizability and the Absorption Spectrum of an Exciton in an Aharonov-Bohm Quantum Ring

  Quantum Physics (arXiv)

Summary: We analytically solve the problem of an exciton (with particles interacting by a delta potential) in a one-dimensional quantum ring in the presence of an Aharonov-Bohm flux. By following a more straightforward method than in earlier works we determine the energy spectrum and the associated eigenfunctions together with other physical properties of the system in closed analytical forms. After finding the energy spectra of the exciton in this system, we then calculate the dynamic linear electric polarizability and the absorption coefficients; we find that the magnetic flux changes the values of the absorption coefficients dramatically and that by changing the value of magnetic flux parameter from 0 to 0.5 dark exciton states states transform to bright ones and vice versa.

A. V. Ghazaryan; A. P. Djotyan; K. Moulopoulos; A. A. Kirakosyan
2011-05-30

261

Induced Fractional Zero-Point Canonical Angular Momentum on Charged Particles of Aharonov - Bohm Vector Potential and "Spectator" Magnetic Field

  Quantum Physics (arXiv)

Summary: The induced fractional zero-point canonical angular momentum on charged particles by the Aharonov - Bohm (AB) vector potential is realized via modified combined traps. It explores new features for this type of quantum effects: In a limit of vanishing mechanical kinetic energy the AB vector potential alone cannot induce a fractional zero-point canonical angular momentum on charged particles at the quantum mechanical level in the AB magnetic field-free region; But for the case of the AB vector potential with another one of a "spectator" magnetic field the AB vector potential induces a fractional zero-point canonical angular momentum in the same limit. The "spectator" one does not contribute to such a fractional zero-point quantity, but plays essential role in guaranteeing non-trivial dynamics survived in this limit at the quantum mechanical level. These results are significance in investigations of the AB effects and related fields for both theories and experiments.

Jian-Zu Zhang
2007-11-02

262

New application of decomposition of U(1) gauge potential:Aharonov-Bohm effect and Anderson-Higgs mechanism

  Quantum Physics (arXiv)

Summary: In this paper we study the Aharonov-Bohm (A-B) effect and Anderson-Higgs mechanism in Ginzburg-Landau model of superconductors from the perspective of the decomposition of U(1) gauge potential. By the Helmholtz theorem, we derive exactly the expression of the transverse gauge potential $\\vec{A}_\\perp$ in A-B experiment, which is gauge-invariant and physical. For the case of a bulk superconductor, we find that the gradient of the total phase field $\\theta$ provides the longitudinal component ${\\vec A}_{\\parallel}$, which reflects the Anderson-Higgs mechanism. For the case of a superconductor ring, the gradient of the longitudinal phase field $\\theta_1$ provides the longitudinal component ${\\vec A}_{\\parallel}$, while the transverse phase field $\\theta_2$ produces new physical effects such as the flux quantization inside a superconducting ring.

Jian-Feng Li; Yu Jiang; Wei-Min Sun; Hong-Shi Zong; Fan Wang
2012-05-29

263

Effective Beam Separation Schemes for the Measurement of the Electric Aharonov-Bohm Effect in an Ion Interferometer

  Quantum Physics (arXiv)

Summary: We propose an experiment for the first proof of the type I electric Aharonov-Bohm effect in an ion interferometer for hydrogen. The performances of three different beam separation schemes are simulated and compared. The coherent ion beam is generated by a single atom tip (SAT) source and separated by either two biprisms with a quadrupole lens, two biprisms with an einzel-lens or three biprisms. The beam path separation is necessary to introduce two metal tubes that can be pulsed with different electric potentials. The high time resolution of a delay line detector allows to work with a continuous ion beam and circumvents the pulsed beam operation as originally suggested by Aharonov and Bohm. We demonstrate, that the higher mass and therefore lower velocity of ions compared to electrons combined with the high expected SAT ion emission puts the direct proof of this quantum effect for the first time into reach of current technical possibilities. Thereby a high coherent ion detection rate is crucial to avoid long integration times that allow the influence of dephasing noise from the environment. We can determine the period of the expected matter wave interference pattern and the signal on the detector by determining the superposition angle of the coherent partial beams. Our simulations were tested with an electron interferometer setup and agree with the experimental results. We determine the separation scheme with three biprisms to be most efficient and predict a total signal acquisition time of only 80 s to measure a phase shift from 0 to 2$\\pi$ due to the electric Aharonov-Bohm effect.

Georg Schütz; Alexander Rembold; Andreas Pooch; Henrike Prochel; Alexander Stibor
2014-12-19

264

Path integral treatment of two- and three-dimensional delta-function potentials and application to spin-1/2 Aharonov-Bohm problem

  HEP - Theory (arXiv)

Summary: Delta-function potentials in two- and three-dimensional quantum mechanics are analyzed by the incorporation of the self-adjoint extension method to the path integral formalism. The energy-dependent Green functions for free particle plus delta-function potential systems are explicitly calculated. Also the energy-dependent Green function for the spin-1/2 Aharonov-Bohm problem is evaluated. It is found that the only one special value of the self-adjoint extension parameter gives a well-defined and non-trivial time-dependent propagator. This special value corresponds to the viewpoint of the spin-1/2 Aharonov-Bohm problem when the delta-function is treated as a limit of the infinitesimal radius.

D. K. Park
1994-05-04

265

He-McKellar-Wilkens effect and Scalar Aharonov-Bohm effect for a neutral particle based on the Lorentz symmetry violation

  HEP - Theory (arXiv)

Summary: In this contribution, we discuss the He-McKellar-Wilkens effect and the Scalar Aharonov-Bohm effect for neutral particles based on the Lorentz symmetry violation background, by showing that the background of the Lorentz symmetry violation yields abelian quantum phases for a neutral particle. We also study the nonrelativistic bound states for a neutral particle interacting with a Coulomb-like potential based on the Lorentz symmetry violation background given by a fixed vector field parallel to the radial direction.

K. Bakke; E. O. Silva; H. Belich
2012-08-08

266

A pragmatic approach to the problem of the self-adjoint extension of Hamilton operators with the Aharonov-Bohm potential

  Quantum Physics (arXiv)

Summary: We consider the problem of self-adjoint extension of Hamilton operators for charged quantum particles in the pure Aharonov-Bohm potential (infinitely thin solenoid). We present a pragmatic approach to the problem based on the orthogonalization of the radial solutions for different quantum numbers. Then we discuss a model of a scalar particle with a magnetic moment which allows to explain why the self-adjoint extension contains arbitrary parameters and give a physical interpretation.

Juergen Audretsch; Ulf Jasper; Vladimir D. Skarzhinsky
1995-03-07

267

Radiative Corrections to the Aharonov-Bohm Scattering L.C. de Albuquerque, M. Gomes and A.J. da Silva ? Instituto de Física, USP

  CiteSeer

Summary: We consider the scattering of relativistic electrons from a thin magnetic flux tube and perturbatively calculate the order ?, radiative correction, to the first order Born approximation. We show also that the second order Born amplitude vanishes, and obtain a finite inclusive cross section for the one-body scattering which incorporates soft photon bremsstrahlung effects. Moreover, we determine the radiatively corrected Aharonov-Bohm potential and, in particular, verify that an induced magnetic field is generated outside of the flux tube.

Typeset Using Revtex
1999-01-01

268

Flux-dependent occupations and occupation difference in geometrically symmetric and energy degenerate double-dot Aharonov-Bohm interferometers

  Quantum Physics (arXiv)

Summary: We study the steady-state characteristics and the transient behavior of the nonequilibrium double-dot Aharonov-Bohm interferometer using analytical tools and numerical simulations. Our simple setup includes noninteracting degenerate quantum dots that are coupled to two biased metallic leads at the same strength. A magnetic flux $\\Phi$ is piercing the setup perpendicularly. As we tune the degenerate dots energies away from the symmetric point we observe four nontrivial magnetic flux control effects: (i) flux dependency of the dots occupation, (ii) magnetic flux induced occupation difference between the dots, at degeneracy, (iii) the effect of "phase-localization" of the dots coherence holds only at the symmetric point, while in general both real and imaginary parts of the coherence are nonzero, and (iv) coherent evolution survives even when the dephasing strength, introduced into our model using B\\"uttiker probe, is large and comparable to the dots energies and the bias voltage. Moreover, not only finite dephasing strength does not destroy the coherence features, it can provide new type of coherent oscillations. These four phenomena take place when the dots energies are gated, to be positioned away from the symmetric point, demonstrating that the combination of bias voltage, magnetic flux and gating field, can provide delicate controllability over the occupation of each of the quantum dots, and their coherence.

Salil Bedkihal; Malay Bandyopadhyay; Dvira Segal
2012-10-25

269

The Spin Interaction of a Dirac Particle in an Aharonov-Bohm Potential in First Order Scattering

  HEP - Theory (arXiv)

Summary: For a Dirac particle in an Aharonov-Bohm (AB) potential, it is shown that the spin interaction (SI) operator which governs the transitions in the spin sector of the first order S-matrix is related to one of the generators of rotation in the spin space of the particle. This operator, which is given by the projection of the spin operator $\\mathbf{\\Sigma}$ along the direction of the total momentum of the system, and the two operators constructed from the projections of the $\\mathbf{\\Sigma}$ operator along the momentum transfer and the z-directions close the SU(2) algebra.It is suggested, then, that these two directions of the total momentum and the momentum transfer form some sort of natural intrinsic directions in terms of which the spin dynamics of the scattering process at first order can be formulated conveniently. A formulation and an interpretation of the conservation of helicity at first order using the spin projection operators along these directions is presented .

A. Albeed; M. S. Shikakhwa
2007-11-13

270

Effect of magnetic flux and of electron momentum on the transmission amplitude in the Aharonov-Bohm ring

  Quantum Physics (arXiv)

Summary: A characterization of the two-terminal open-ring Aharonov-Bohm interferometer is made by analyzing the phase space plots in the complex transmission amplitude plane. Two types of plots are considered: type I plot which uses the magnetic flux as the variable parameter and type II plot which uses the electron momentum as the variable parameter. In type I plot, the trajectory closes upon itself only when the ratio $R$ of the arm lengths (of the interferometer) is a rational fraction, the shape and the type of the generated flower-like pattern is sensitive to the electron momentum. For momenta corresponding to discrete eigenstates of the perfect ring (i.e. the ring without the leads), the trajectory passes through the origin a certain fixed number of times before closing upon itself, whereas for arbitrary momenta it never passes through the origin. Although the transmission coefficient is periodic in the flux with the elementary flux quantum as the basic period, the phenomenon of electron transmission is shown not to be so when analyzed via the present technique. The periodicity is seen to spread over several flux units whenever $R$ is a rational fraction whereas there is absolutely no periodicity present when $R$ is an irrational number. In type II plot, closed trajectories passing through the origin a number of times are seen for $R$ being a rational fraction. The case R=1 (i.e. a symmetric ring) with zero flux is rather pathological--it presents a closed loop surrounding the origin. For irrational $R$ values, the trajectories never close.

M. V. Amaresh Kumar; Debendranath Sahoo
2005-06-25

271

Single-Particle Density of States for the Aharonov-Bohm Potential and Instability of Matter with Anomalous Magnetic Moment in 2+1 Dimensions

  HEP - Theory (arXiv)

Summary: In the nonrelativistic case we find that whenever the relation $mc^2/e^2 2$ (note that $g_m=2.00232$ for the electron), then the matter is unstable against formation of the flux $\\al$. The result persists down to $g_m=2$ provided the Aharonov-Bohm potential is supplemented with a short range attractive potential. We also show that whenever a bound state is present in the spectrum it is always accompanied by a resonance with the energy proportional to the absolute value of the binding energy. is considered. For the Klein-Gordon equation with the Pauli coupling which exists in (2+1) dimensions without any reference to a spin the matter is again unstable for $g_m>2$. The results are obtained by calculating the change of the density of states induced by the Aharonov-Bohm potential. The Krein-Friedel formula for this long-ranged potential is shown to be valid when supplemented with zeta function regularization. PACS : 03.65.Bz, 03-70.+k, 03-80.+r, 05.30.Fk

Alexander MOROZ
1994-05-05

272

Polarized excitons in nanorings and the optical Aharonov-Bohm effect A. O. Govorov

  Physics Websites

Summary: in semiconductors, and are responsible for optical emission of crystals at low temperatures. The predicted in no sensitivity to magnetic flux would be expected. We propose a mechanism for the topologi- cal phase that this magnetic-field induced phase may strongly affect excitons in a system with cylindrical symmetry, resulting

Ludwig-Maximilians-Universität, München

273

The Single-Particle density of States, Bound States, Phase-Shift Flip, and a Resonance in the Presence of an Aharonov-Bohm Potential

  Quantum Physics (arXiv)

Summary: Both the nonrelativistic scattering and the spectrum in the presence of the Aharonov-Bohm potential are analyzed. The single-particle density of states (DOS) for different self-adjoint extensions is calculated. The DOS provides a link between different physical quantities and is a natural starting point for their calculation. The consequences of an asymmetry of the S matrix for the generic self-adjoint extension are examined. I. Introduction II. Impenetrable flux tube and the density of states III. Penetrable flux tube and self-adjoint extensions IV. The S matrix and scattering cross sections V. The Krein-Friedel formula and the resonance VI. Regularization VII. The R --> 0 limit and the interpretation of self-adjoint extensions VIII. Energy calculations IX. The Hall effect in the dilute vortex limit X. Persistent current of free electrons in the plane pierced by a flux tube XI. The 2nd virial coefficient of nonrelativistic interacting anyons XII. Discussion of the results and open questions

Alexander Moroz
1996-02-08

274

Observability of the scalar Aharonov-Bohm effect inside a 3D Faraday cage with time-varying exterior charges and masses

  CERN Preprints

Summary: In this paper we investigate the scalar Aharonov-Bohm (AB) effect in two of its forms, i.e., its electric form and its gravitational form. The standard form of the electric AB effect involves having particles (such as electrons) move in regions with zero electric field but different electric potentials. When a particle is recombined with itself, it will have a different phase, which can show up as a change in the way the single particle interferes with itself when it is recombined with itself. In the case where one has quasi-static fields and potentials, the particle will invariably encounter fringing fields, which makes the theoretical and experimental status of the electric AB effect much less clear than that of the magnetic (or vector) AB effect. Here we propose using time varying fields outside of a spherical shell, and potentials inside a spherical shell to experimentally test the scalar AB effect. In our proposal a quantum system will always be in a field-free region but subjected to a non-zero time-var...

Chiao, R Y; Sundqvist, K M; Inan, N A; Munoz, G A; Singleton, D A; Kang, B S; Martinez, L A
2014-01-01

275

Real-time dynamics of spin-dependent transport through a double-quantum-dot Aharonov-Bohm interferometer with spin-orbit interaction

  Quantum Physics (arXiv)

Summary: The spin-resolved non-equilibrium real-time electron transport through a double-quantum-dot (DQD) Aharonov-Bohm (AB) interferometer with spin-orbit interaction (SOI) is explored. The SOI and AB interference in the real-time dynamics of spin transport is expressed by effective magnetic fluxes. Analytical formulae for the time-dependent currents, for initially unpolarized spins, are presented. In many cases, there appear spin currents in the electrodes, for which the spins in each electrode are polarized along characteristic directions, pre-determined by the SOI parameters and by the geometry of the system. Special choices of the system parameters yield steady-state currents in which the spins are fully polarized along these characteristic directions. The time required to reach this steady state depends on the couplings of the DQD to the leads. The magnitudes of the currents depend strongly on the SOI-induced effective fluxes. Without the magnetic flux, the spin-polarized current cannot be sustained to the steady states, due to the phase rigidity for this system. For a non-degenerate DQD, transient spin transport can be produced by the sole effects of SOI. We also show that one can extract the spin-resolved currents from measurements of the total charge current.

Matisse Wei-Yuan Tu; Amnon Aharony; Wei-Min Zhang; Ora Entin-Wohlman
2014-10-02

276

Novel Aharonov-Bohm-like effect: Detectability of the vector potential in a solenoidal configuration with a ferromagnetic core covered by superconducting lead, and surrounded by a thin cylindrical shell of aluminum

  Quantum Physics (arXiv)

Summary: The flux as measured by the Josephson effect in a SQUID-like configuration with a ferromagnetic core inserted into its center, is shown to be sensitive to the vector potential arising from the central ferromagnetic core, even when the core is covered with a superconducting material that prevents any magnetic field lines from ever reaching the perimeter of the SQUID-like configuration. This leads to a macroscopic, Aharonov-Bohm-like effect that is observable in an asymmetric hysteresis loop in the response of the SQUID-like configuration to an externally applied magnetic field.

R. Y. Chiao
2012-06-23

277

Hysteretic method for measuring the flux trapped within the core of a superconducting lead-coated ferromagnetic torus by a linked superconducting tin ring, in a novel Aharonov-Bohm-like effect based on the Feynman path-integral principle

  CERN Preprints

Summary: A novel kind of nonlocal, macroscopic Aharonov-Bohm effect involving two topologically linked superconducting rings made out of two different materials, namely, lead and tin, is suggested for experimental observation, in which the lead ring is a torus containing a core composed of permanently magnetized ferromagnetic material. It is predicted that the remnant fields in a hysteresis loop induced by the application of a magnetic field imposed by a large external pair of Helmholtz coils upon the tin ring, will be asymmetric with respect to the origin of the loop. An appendix based on Feynman's path-integral principle is the basis for these predictions.

Chiao, Raymond
2012-01-01

278

Observability of the scalar Aharonov-Bohm effect inside a 3D Faraday cage with time-varying exterior charges and masses

  Quantum Physics (arXiv)

Summary: In this paper we investigate the scalar Aharonov-Bohm (AB) effect in two of its forms, i.e., its electric form and its gravitational form. The standard form of the electric AB effect involves having particles (such as electrons) move in regions with zero electric field but different electric potentials. When a particle is recombined with itself, it will have a different phase, which can show up as a change in the way the single particle interferes with itself when it is recombined with itself. In the case where one has quasi-static fields and potentials, the particle will invariably encounter fringing fields, which makes the theoretical and experimental status of the electric AB effect much less clear than that of the magnetic (or vector) AB effect. Here we propose using time varying fields outside of a spherical shell, and potentials inside a spherical shell to experimentally test the scalar AB effect. In our proposal a quantum system will always be in a field-free region but subjected to a non-zero time-varying potentials. Furthermore, our system will not be spatially split and brought back together as in the magnetic AB experiment. Therefore there is no spatial interference and hence no shift in a spatial interference pattern to observe. Rather, there arises purely temporal interference phenomena. As in the magnetic AB experiments, these effects are non-classical. We present two versions of this idea: (i) a Josephson temporal interferometry experiment inside a superconducting spherical shell with a time-varying surface charge; (ii) a two-level atom experiment in which the atomic spectrum acquires FM sidebands when it is placed inside a spherical shell whose exterior mass is sinusoidally varying with time. The former leads to a time-varying internal magnetic field, and the latter leads to a time-varying gravitational redshift.

R. Y. Chiao; X. H. Deng; K. M. Sundqvist; N. A. Inan; G. A. Munoz; D. A. Singleton; B. S. Kang; L. A. Martinez
2014-11-13

279

AnomalousAnomalous AharonovBohmAharonovBohm gapgap

  Physics Websites

Summary: et al. Science 304, 1129 (2004) The lowest excitonic peak moves to lower energy as the field. Bachtold et al., Nature 397, 673 (1999) S. Zaric et al. Science 304, 1129 (2004) The lowest excitonic peak. Zaric et al. Science 304, 1129 (2004) =B RCNT 2 #12;CNTs in a uniform B field: The Lorentz correction

Marini, Andrea

280

J. Phys. III Yance 7 (1997) 1515-1520 JULY 1997, PAGE 1515 Aharonov-Bohm Interference of Holes at Dislocations in

  Computer Technologies and Information Sciences Websites

Summary: and other imperfections PACS.73 40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions interference of holes in macroscopic semiconductor sample containing an array of straight-line dislocations properties of semiconductor crystals. The latter are mainly affected by the presence of localised (at least m

Boyer, Edmond

281

The Aharonov-Bohm Problem Revisited

  HEP - Theory (arXiv)

Summary: The properties of a nonrelativistic charged particle in two dimensions in the presence of an arbitrary number of nonquantized magnetic fluxes are investigated in free space as well as in a uniform magnetic field. The fluxes are represented mathematically as branch points in one of the complex coordinates. It is found that in order to construct solutions, the fluxes have to be treated in general as dynamical objects dual to the charges. A medium made up of fluxes acts like an anti-magnetic field and tends to expel the charges.

Yoichiro Nambu
1999-06-28

282

The Casimir-Aharonov-Bohm effect?

  HEP - Theory (arXiv)

Summary: The combined effect of the magnetic field background in the form of a singular vortex and the Dirichlet boundary condition at the location of the vortex on the vacuum of quantized scalar field is studied. We find the induced vacuum energy density and current to be periodic functions of the vortex flux and holomorphic functions of the space dimension.

Yu. A. Sitenko; A. Yu. Babansky
1997-10-24

283

Creation of two-dimensional coulomb crystals of ions in oblate Paul traps for quantum simulations

  Quantum Physics (arXiv)

Summary: We develop the theory to describe the equilibrium ion positions and phonon modes for a trapped ion quantum simulator in an oblate Paul trap that creates two-dimensional Coulomb crystals in a triangular lattice. By coupling the internal states of the ions to laser beams propagating along the symmetry axis, we study the effective Ising spin-spin interactions that are mediated via the axial phonons and are less sensitive to ion micromotion. We find that the axial mode frequencies permit the programming of Ising interactions with inverse power law spin-spin couplings that can be tuned from uniform to $r^{-3}$ with DC voltages. Such a trap could allow for interesting new geometrical configurations for quantum simulations on moderately sized systems including frustrated magnetism on triangular lattices or Aharonov-Bohm effects on ion tunneling. The trap also incorporates periodic boundary conditions around loops which could be employed to examine time crystals.

Bryce Yoshimura; Marybeth Stork; Danilo Dadic; W. C. Campbell; J. K. Freericks
2014-06-20

284

Creation of two-dimensional coulomb crystals of ions in oblate Paul traps for quantum simulations

  CERN Preprints

Summary: We develop the theory to describe the equilibrium ion positions and phonon modes for a trapped ion quantum simulator in an oblate Paul trap that creates two-dimensional Coulomb crystals in a triangular lattice. By coupling the internal states of the ions to laser beams propagating along the symmetry axis, we study the effective Ising spin-spin interactions that are mediated via the axial phonons and are less sensitive to ion micromotion. We find that the axial mode frequencies permit the programming of Ising interactions with inverse power law spin-spin couplings that can be tuned from uniform to $r^{-3}$ with DC voltages. Such a trap could allow for interesting new geometrical configurations for quantum simulations on moderately sized systems including frustrated magnetism on triangular lattices or Aharonov-Bohm effects on ion tunneling. The trap also incorporates periodic boundary conditions around loops which could be employed to examine time crystals.

Yoshimura, Bryce; Dadic, Danilo; Campbell, W C; Freericks, J K
2014-01-01

285

Bremsstrahlung of relativistic electrons in the Aharonov-Bohm potential

  HEP - Theory (arXiv)

Summary: We investigate the scattering of an electron by an infinitely thin and infinitely long straight magnetic flux tube in the framework of QED. We discuss the solutions of the Dirac and Maxwell fields in the related external pure AB potential and evaluate matrix elements and differential probabilities for the bremsstrahlung process. The dependence of the resulting cross section on the energy, direction and polarization of the involved particles is analyzed. In the low energy regime a surprising angular asymmetry is found which results from the interaction of the electron's magnetic moment with the magnetic field.

J. Audretsch; Ulf. Jasper; V. D. Skarzhinsky
1997-09-18

286

Detecting Noncommutative Phase Space by Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: Noncommutative phase space plays an essential role in particle physics and quantum gravity at the Planck scale. However, direct experimental evidence or observation to demonstrate the existence of noncommutative phase space is still lacking.We study a quantum ring in noncommutative phase space based on the Seiberg-Witten map and give the effective magnetic potential and field coming from the noncommutative phase space, which induces the persistent current in the ring. We introduce two variables as two signatures to detect the noncommutative phase space and propose an experimental scheme to detect the noncommutative phase space as long as we measure the persistent current and the external magnetic flux.

Shi-Dong Liang; Haoqi Li; Guang-Yao Huang
2015-02-02

287

Induced Current and Aharonov-Bohm Effect in Graphene

  Mathematical Physics (arXiv)

Summary: The effect of vacuum polarization in the field of an infinitesimally thin solenoid at distances much larger than the radius of solenoid is investigated. The induced charge density and induced current are calculated. Though the induced charge density turned out to be zero, the induced current is finite periodical function of the magnetic flux $\\Phi$. The expression for this function is found exactly in a value of the flux. The induced current is equal to zero at the integer values of $\\Phi/\\Phi_0$ as well as at half-integer values of this ratio, where $\\Phi_0=2\\pi\\hbar c/e$ is the elementary magnetic flux. The latter is a consequence of the Furry theorem and periodicity of the induced current with respect to magnetic flux. As an example we consider the graphene in the field of solenoid perpendicular to the plane of a sample.

R. Jackiw; A. I. Milstein; S. -Y. Pi; I. S. Terekhov
2009-07-20

288

The Dynamical Mechanism of the Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: In this paper, it is emphasized that the dynamical cause for the A-B effect is the superimposed energy between the magnetic field produced by the moving charges and that in the solenoid, instead of the existence of the vector potential. If such a superposition between the magnetic fields can be eliminated, the A-B effect should not be observed any more. To verify this viewpoint, a new experimental method using a SQUID is suggested in this paper.

R. F. Wang
2007-05-28

289

Comment on Macroscopic Test of the Aharonov-Bohm Effect

  Quantum Physics (arXiv)

Summary: In this Comment it is shown that it cannot be argued that in the magnetic AB effect there is no force acting on the particle, i.e., that the observed phase shift is entirely due to nonzero vector potential. In stationary resistive conductors carrying constant currents there are quasistatic surface charges, which generate not only the electric field inside the wire driving the current, but also a static electric field outside it. These external static electric fields have nothing to do with Boyer's force picture and with his result for the existence of a time delay.

Tomislav Ivezic
2014-06-04

290

Aharonov-Bohm effect in curved space and cosmic strings

  Mathematical Physics (arXiv)

Summary: A quantum theory is developed for the scattering of a nonrelativistic particle in the field of a cosmic string regarded as a combination of a magnetic and gravitational strings. Allowance is made for the effects due to the finite transverse dimensions of the string under fairly general assumptions about the distribution of the magnetic field and spatial curvature in the string. It is shown that in a definite range of angles the differential cross section at all absolute values of the wave vector of the incident particle depends strongly on the magnetic flux of the string.

Yurii Sitenko; Alexei Mishchenko
1999-01-18

291

Mathematical justification of the Aharonov-Bohm hamiltonian

  Mathematics Websites

Summary: S , the interpretation in [?], and followed by a huge amount of papers, is that A plays a prominent role in quantum), but here we concentrate on the more realistic case of radius a > 0. There are controversies over


292

Spinless Aharonov-Bohm problem in curved space

  Mathematical Physics (arXiv)

Summary: The dynamics of a spinless charged particle under the influence of a magnetic field in curved space is considered. We chose the surface as being a cone defined by a line element in polar coordinates. The geometry of this line element establishes that the motion of the particle can occur on the surface of a cone or an anti-cone. As a consequence of the nontrivial topology of the cone and also because of two-dimensional confinement, the geometric potential should be taken into account. At first, we establish the conditions for the particle describing a circular path in such a context. Because of the presence of the geometric potential, which contains a singular term, we use the self-adjoint extension method in order to describe the dynamics in all space including the singularity. Expressions are obtained for the bound state energies and wave functions.

Edilberto O. Silva; Sérgio C. Ulhoa; Fabiano M. Andrade; Cleverson Filgueiras; R. G. G. Amorin
2015-02-25

293

Spectral Zeta Functions for Spherical Aharonov-Bohm Quantum Bags

  HEP - Theory (arXiv)

Summary: We study the sum $\\ds\\zeta_H(s)=\\sum_j E_j^{-s}$ over the eigenvalues $E_j$ of the Schrdinger equation in a spherical domain with Dirichlet walls, threaded by a line of magnetic flux. Rather than using Green's function techniques, we tackle the mathematically nontrivial problem of finding exact sum rules for the zeros of Bessel functions $J_{\

E. Elizalde; S. Leseduarte; A. Romeo
1992-12-16

294

Simulating the Aharonov-Bohm Effect Frank Rioux

  Chemistry Websites

Summary: screen, with the interference pattern shifted when a magnetic field B is turned on in the cylindrical. The most commonly described case occurs when the wave function of an electron passing around a long and displayed below. Please consult other tutorials on the double-slit interference effect on my page

Rioux, Frank

295

Field Asymmetry of mesoscopic rectification In Aharonov Bohm Rings

  Materials Science Websites

Summary: #12;Field Asymmetry of mesoscopic rectification Why is non linear mesoscopic transport interesting probes Magnetoconductance symmetric in magnetic field Not true for non linear transport! I = G1 V + G2 V of el-el interactions! Conductor between 2 reservoirs 1 2 B #12;Magnetochiral classical non linear

Fominov, Yakov

296

Numerical analysis of nodal sets for eigenvalues of Aharonov-Bohm Hamiltonians on the square

  Mathematics Websites

Summary: of the associated eigenfunctions as a function of the pole. This leads us to discover new candidates for minimal k;meeting (with equal angle) at critical points of their boundary set can be odd [14]. Here by critical results of [14] and [15] with efficient numerical computations to exhibit some candidates to be minimal 3

Bonnaillie-Noël, Virginie

297

Numerical analysis of nodal sets for eigenvalues of Aharonov-Bohm Hamiltonians on the square

  Physics Websites

Summary: candidates for minimal k-partitions of the square with a specific topolog- ical type. This illustrates also on the square as a function of the pole and propose new candidates for minimal k-partitions of a specific that the number of half-lines meeting (with equal angle) at critical points of their boundary set can be odd [12

Paris-Sud XI, Université de

298

"Level Curvature" Distribution for Diffusive Aharonov-Bohm Systems: analytical results

  Nonlinear Sciences (arXiv)

Summary: We calculate analytically the distributions of "level curvatures" (LC) (the second derivatives of eigenvalues with respect to a magnetic flux) for a particle moving in a white-noise random potential. We find that the Zakrzewski-Delande conjecture is still valid even if the lowest weak localization corrections are taken into account. The ratio of mean level curvature modulus to mean dissipative conductance is proved to be universal and equal to $2\\pi$ in agreement with available numerical data.

Yan V. Fyodorov; H-J. Sommers
1994-12-24

299

String Representation of the Abelian Higgs Theory and Aharonov-Bohm Effect on the Lattice

  CERN Preprints

Summary: The partition function of the $4D$ lattice Abelian Higgs theory is represented as the sum over world sheets of Nielsen--Olesen strings. The creation and annihilation operators of the strings are constructed. The topological long--range interaction of the strings and charged particles is shown to exist; it is proportional to the linking number of the string world sheet and particle world trajectory.

Polikarpov, M I; Zubkov, M A
1993-01-01

300

Non-Abelian Aharonov-Bohm Scattering of Spin 1/2 Particles

  HEP - Theory (arXiv)

Summary: We study the low energy regime of the scattering of two fermionic particles carrying isospin 1/2 and interacting through a non-Abelian Chern-Simons field. We calculate the one-loop scattering amplitude for both the nonrelativistic and also for the relativistic theory. In the relativistic case we introduce an intermediate cutoff, separating the regions with low and high loop momenta integration. In this procedure purely relativistic field theory effects as the vacuum polarization and anomalous magnetic moment corrections are automatically incorporated.

M. Gomes; L. C. Malacarne; A. J. da Silva
2000-04-24

301

Random Aharonov-Bohm vortices and some exact families of integrals: Part III

  Mathematical Physics (arXiv)

Summary: As a sequel to [1] and [2], I present some recent progress on Bessel integrals $\\int_0^{\\infty}{\\rmd u}\\; uK_0(u)^{n}$, $\\int_0^{\\infty}{\\rmd u}\\; u^{3}K_0(u)^{n}$, ... where the power of the integration variable is odd and where $n$, the Bessel weight, is a positive integer. Some of these integrals for weights n=3 and n=4 are known to be intimately related to the zeta numbers zeta(2) and zeta(3). Starting from a Feynman diagram inspired representation in terms of n dimensional multiple integrals on an infinite domain, one shows how to partially integrate to n-2 dimensional multiple integrals on a finite domain. In this process the Bessel integrals are shown to be periods. Interestingly enough, these "reduced" multiple integrals can be considered in parallel with some simple integral representations of zeta numbers. One also generalizes the construction of [2] on a particular sum of double nested Bessel integrals to a whole family of double nested integrals. Finally a strong PSLQ numerical evidence is shown to support a surprisingly simple expression of zeta(5) as a linear combination with rational coefficients of Bessel integrals of weight n= 8.

Stephane Ouvry
2014-01-30

302

Comment on "Aharonov-Casher and Scalar Aharonov-Bohm Topological Effects"

  Quantum Physics (arXiv)

Summary: In this Comment we point out (i) that the Hamiltonian, Eq. (17) in the Letter(Phys. Rev. Lett. 108, 070405 (2012)), is not a relativistic Hamiltonian, (ii) then that the conditions in the Letter are irrelevant for a topological AC and SAB effects, and (iii) conclusively that the non-relativistic Hamiltonian employed by Peshkin and Lipkin (Phys. Rev. Lett. 74, 2847 (1995)) has the same $U(1)_{mm}$ gauge structure for a fixed spin and then is not wrong, but their incorrect interpretation of the spin autocorrelations led to the incorrect conclusion.

Taeseung Choi; Sam Young Cho
2013-11-16

303

On the dynamics created by a time--dependent Aharonov-Bohm flux

  Mathematical Physics (arXiv)

Summary: We study the dynamics of classical and quantum particles moving in a punctured plane under the influence of a homogeneous magnetic field and driven by a time-dependent singular flux tube through the hole.

J. Asch; P. Stovicek
2007-10-17

304

Coherent and semiclassical states in magnetic field in the presence of the Aharonov-Bohm solenoid

  Quantum Physics (arXiv)

Summary: A new approach to constructing coherent states (CS) and semiclassical states (SS) in magnetic-solenoid field is proposed. The main idea is based on the fact that the AB solenoid breaks the translational symmetry in the xy-plane, this has a topological effect such that there appear two types of trajectories which embrace and do not embrace the solenoid. Due to this fact, one has to construct two different kinds of CS/SS, which correspond to such trajectories in the semiclassical limit. Following this idea, we construct CS in two steps, first the instantaneous CS (ICS) and the time dependent CS/SS as an evolution of the ICS. The construction is realized for nonrelativistic and relativistic spinning particles both in (2+1)- and (3+1)- dimensions and gives a non-trivial example of SS/CS for systems with a nonquadratic Hamiltonian. It is stressed that CS depending on their parameters (quantum numbers) describe both pure quantum and semiclassical states. An analysis is represented that classifies parameters of the CS in such respect. Such a classification is used for the semiclassical decompositions of various physical quantities.

V. G. Bagrov; S. P. Gavrilov; D. M. Gitman; D. P. Meira Filho
2011-08-25

305

Dynamics of a classical Hall system driven by a time-dependent Aharonov--Bohm flux

  Mathematical Physics (arXiv)

Summary: We study the dynamics of a classical particle moving in a punctured plane under the influence of a strong homogeneous magnetic field, an electrical background, and driven by a time-dependent singular flux tube through the hole. We exhibit a striking classical (de)localization effect: in the far past the trajectories are spirals around a bound center; the particle moves inward towards the flux tube loosing kinetic energy. After hitting the puncture it becomes ``conducting'': the motion is a cycloid around a center whose drift is outgoing, orthogonal to the electric field, diffusive, and without energy loss.

J. Asch; P. Stovicek
2006-09-13

306

Consistency of the Born Approximation for the spin-1/2 Aharonov-Bohm Scattering

  HEP - Theory (arXiv)

Summary: The relativistic scattering of a spin-1/2 particle from an infinitely long solenoid is considered in the framework of covariant perturbation theory. The first order term agrees with the corresponding term in the series expansion of the exact amplitude, and second order term vanishes, thus proving that Born approximation is consistent.

M. Boz; N. K. Pak
2000-04-24

307

Semiclassical Explanation of the Matteucci-Pozzi and Aharonov-Bohm Phase Shifts

  Quantum Physics (arXiv)

Summary: Classical electromagnetic forces can account for the experimentally observed phase shifts seen in an electron interference pattern when a line of electric dipoles or a line of magnetic dipoles (a solenoid) is placed between the electron beams forming the interference pattern.

Timothy H. Boyer
2001-07-19

308

String Representation of the Abelian Higgs Theory and Aharonov-Bohm Effect on the Lattice

  HEP - Lattice (arXiv)

Summary: The partition function of the $4D$ lattice Abelian Higgs theory is represented as the sum over world sheets of Nielsen--Olesen strings. The creation and annihilation operators of the strings are constructed. The topological long--range interaction of the strings and charged particles is shown to exist; it is proportional to the linking number of the string world sheet and particle world trajectory.

M. I. Polikarpov; U. -J. Wiese; M. A. Zubkov
1993-03-26

309

Inelastic Effects in Aharonov-Bohm Molecular Interferometers Oded Hod,1,* Roi Baer,2

  Chemistry Websites

Summary: interferometer becomes more sensitive to the threading magnetic flux as the electron-phonon coupling is increased to shift conductance peaks into the low-bias regime. Magnetic fields, on the other hand, have been rarely used due to the small magnetic flux captured by molecular conductors (an exception is the Kondo effect

Hod, Oded

310

AharonovBohm Effect in Resonances of Magnetic Schrodinger Operators with

  Mathematics Websites

Summary: Aharonov­Bohm Effect in Resonances of Magnetic Schr¨odinger Operators with Potentials with Supports@ecu.edu Hideo Tamura : tamura@math.okayama-u.ac.jp 0 #12;Aharonov­Bohm Effect in Resonances of Magnetic Schr]). In this work we study the AB effect in resonances through scattering by electrostatic and magnetic fields

Alexandrova, Ivana

311

Coulomb blockade double-dot Aharonov-Bohm interferometer: harmonic decomposition of the interference pattern

  Quantum Physics (arXiv)

Summary: For the solid state double-dot interferometer, the phase shifted interference pattern induced by the interplay of inter-dot Coulomb correlation and multiple reflections is analyzed by harmonic decomposition. Unexpected result is uncovered, and is discussed in connection with the which-path detection and electron loss.

Feng Li; HuJun Jiao; Hui Wang; JunYan Luo; Xin-Qi Li
2009-06-19

312

Anomalous Aharonov-Bohm-Type Effects in Square Array of Antidots

  Materials Science Websites

Summary: period and antidot radius were a=1 µm and r=350 nm in all arrays. -40 -20 0 20 40 xx() 3.543.523.503.483.46 Magnetic Field (T) -50 0 50 xx() 6.886.866.846.82 Magnetic Field (T) (a) (b) (c) 4 3 2 1 0 xx(k) 8 6 4 2 0 B(mT) 86420 Magnetic Field (T) B xx =4 =2 b c FIGURE 1. (a) Magnetoresistivity (right axis) of a 5

Katsumoto, Shingo

313

Comment on "On the Electric Charge Quantization from the Aharonov-Bohm Potential"

  Quantum Physics (arXiv)

Summary: In the paper quant-ph/0503212, Barone and Halayel-Neto (BH) claim that charge quantization in quantum mechanics can be proven without the need for the existence of magnetic monopoles. In this paper it is argued that their claim is untrue.

R. MacKenzie; H. Paquette; J. Pinel; P. -L. Roussel
2005-04-07

314

An inverse scattering problem with the AharonovBohm effect Francois Nicoleau

  Mathematics Websites

Summary: ­Bohm effect. In dimension greater or equal to three, we show that the electric potential and the magnetic­dimensional case). In this note, we study Schr¨odinger operators with an electric potential and a magnetic field­operator. 1 #12; This method can be used to study Hamiltonians with electric and magnetic potentials 6 on L 2

Nicoleau, François

315

Resistance Fluctuations and AharonovBohm-Type Oscillations in Antidot Arrays in the Quantum Hall Regime

  Physics Websites

Summary: Resistance Fluctuations and Aharonov­Bohm-Type Oscillations in Antidot Arrays in the Quantum Hall in the quantum Hall regime are studied. Magnetoresistance of finite antidot array systems in the quantum Hall in the present case. KEYWORDS: GaAs/AlGaAs, two-dimensional electron system, quantum Hall effect, antidot array

Iye, Yasuhiro

316

Anomaly and Thermodynamics for 2D Spinors in the Aharonov--Bohm Gauge Field

  HEP - Theory (arXiv)

Summary: The axial anomaly is computed for Euclidean Dirac fermions on the plane. The dependence upon the self-adjoint extensions of the Dirac operator is investigated and its relevance concerning the second virial coefficient of the anyon gas is discussed.

P. Giacconi; F. Maltoni; R. Soldati
1994-09-19

317

On the spectrum of the Schrodinger Operator with Aharonov-Bohm Magnetic Field in quantum

  Mathematics Websites

Summary: ]. In the limit of the vanishing Dirichlet part of the border the reciprocal of the first eigenvalue describes the mean first passage time of Brownian motion to D. In cellular biology, the study of the diffusive motion


318

Generalized Aharonov-Bohm effect and topological states in graphene nanorings

  Physics Websites

Summary: : any two of the three 2x2 Pauli matrices scalar field / position-dependent mass m equation a and b: any two of the three 2x2 Pauli matrices scalar field / position-dependent mass m ring in the reczag trigonal flake #12;Relativistic quantum-field-theory Lagrangian 1D Generalized Dirac

Yannouleas, Constantine

319

Scaling of Aharonov-Bohm couplings and the dynamical vacuum in gauge theories

  CERN Preprints

Summary: Recent results on the vacuum polarization induced by a thin string of magnetic flux lead us to suggest an analogue of the Copenhagen `flux spaghetti' QCD vacuum as a possible mechanism for avoiding the divergence of perturbative QED, thus permitting consistent completion of the full, nonperturbative theory. The mechanism appears to operate for spinor, but not scalar, QED.

Goldhaber, A S; Parwani, R R; Goldhaber, Alfred S.; Li, Hsiang-Nan; Parwani, Rajesh R.
1995-01-01

320

Quantum mechanical complementarity probed in a closed-loop AharonovBohm

  Physics Websites

Summary: ; doi:10.1038/nphys854 The complementarity principle1 demands that a particle reveals wave-state interferometers with phase-coherent electrons6 . In the latter experiment, a charge detector embedded near one on electron dephasing in an Aharonov­Bohm ring interferometer7 via a charge detector adjacent to the ring

Heiblum, Mordehai "Moty"

321

ON THE MATHEMATICAL THEORY OF THE AHARONOV-BOHM Ph. Roux and D. Yafaev

  Mathematics Websites

Summary: of short-range (satisfying the condition O(jxj 1 " ), " > 0, at in#12;nity) electric and magnetic the case of short-range magnetic and electric potentials (as well as from the electric Coulomb potential ) with a magnetic potential A(x) = a(^x)( x 2 ; x 1 )jxj 2 , where a is an arbitrary function on the unit circle


322

PHYSICAL REVIEW B 85, 165434 (2012) Patterns of the Aharonov-Bohm oscillations in graphene nanorings

  Physics Websites

Summary: in the last couple of years. Surprisingly, these graphene-ring studies have been inconclusive regarding of Technology, Atlanta, Georgia 30332-0430, USA (Received 2 December 2011; revised manuscript received 3 April 2012; published 17 April 2012) Using extensive tight-binding calculations, we investigate (including

Yannouleas, Constantine
2012-01-01

323

Can the Aharonov-Bohm effect be used to detect or refute superseparability?

  Quantum Physics (arXiv)

Summary: The existence of inequivalent irreducible unitary representations of the CCR suggests that two identical charged bosons may, under suitable conditions, be unable to interact with each other even though their wave functions overlap considerably in space at a fixed time. An experiment is proposed to test this possibility.

R N Sen
2010-02-02

324

Dynamics of a classical Hall system driven by a time-dependent AharonovBohm flux

  Mathematics Websites

Summary: the influence of a strong homogeneous magnetic field, an electrical background, and driven by a time is a cycloid around a center whose drift is outgoing, orthogonal to the electric field, diffusive, and without: generation, recombina- tion, lifetime, trapping, mean free paths 1 Introduction The motivation to study


325

Observation of an enhanced AharonovBohm effect K. Kobayashia,*, H. Aikawaa

  Materials Science Websites

Summary: 277-8581, Japan b CREST, Japan Science and Technology Corporation, Mejiro, Tokyo 171-0031, Japan®guration than that obtained in the conventional four-terminal con®guration and the AB phase can be continuously temperature than that in the conventional one. The present result indicates that decoherence is affected

Katsumoto, Shingo

326

Interaction between a moving electron and magnetic flux in Aharonov-Bohm effect

  Quantum Physics (arXiv)

Summary: The back-action exerted by the moving electron on the magnetic flux in the A-B effect is analyzed. It is emphasized that a reasonable interpretation on the A-B effect should be consistent with the uncertain principle. If the back-action on the magnetic flux is reduced to zero, the A-B effect should not be observed, even through the vector potential still exists in space. To verify this interpretation, a new experimental scheme is proposed in this paper.

Wang Rui-Feng
2013-12-21

327

Aharonov-Bohm E ect and Time-Dependent Inverse Scattering Ricardo Weder y

  Mathematics Websites

Summary: , it reduces to a problem in R 2 . We #12;rst consider an unshielded magnetic #12;eld that has a singular part. We then consider the case where the singular part of the magnetic #12;eld is shielded inside a cylinder whose transversal section is compact set K, and there is also a regular magnetic #12;eld


328

Self-adjoint Schrodinger and Dirac operators with Aharonov-Bohm and magnetic-solenoid fields

  Quantum Physics (arXiv)

Summary: We study all the s.a. Schrodinger and Dirac operators (Hamiltonians) both with pure AB field and with magnetic-solenoid field. Then, we perform a complete spectral analysis for these operators, which includes finding spectra and spectral decompositions, or inversion formulas. In constructing the Hamiltonians and performing their spectral analysis, we respectively follow the von Neumann theory of s.a. extensions of symmetric differential operators and the Krein method of guiding functionals. The examples of similar consideration are given by us in arXiv:0903.5277, where a nonrelativistic particle in the Calogero potential field is considered and in Theor. Math. Phys. 150 (1) (2007) 34, where a Dirac particle in the Coulomb field of arbitrary charge is considered. However, due to peculiarities of the three-dimensional problems under consideration, we elaborated a generalization of the approach used in the study of the Dirac particle.

D. M. Gitman; A. Smirnov; I. V. Tyutin; B. L. Voronov
2009-11-04

329

Aharonov-Bohm effect and nucleon-nucleon phase shifts on the lattice

  HEP - Lattice (arXiv)

Summary: We propose a method for the lattice QCD computation of nucleon-nucleon low-energy interactions. It consists in simulating QCD in the background of a ''electromagnetic" field whose potential is non-vanishing, but whose field strength is zero. By tuning the background field, phase-shifts at any (but small) momenta can be determined by measuring the shift of the ground state energy. Lattice sizes as small as 5 Fermi can be sufficient for the calculation of phase shifts up to momenta of order of $m_{\\pi}/2$.

Paulo F. Bedaque
2004-02-14

330

Aharonov-Bohm effect in the chiral Luttinger liquid Michael R. Geller

  Physics Websites

Summary: in the fractional regime should be chiral Luttinger liquids CLL . As in the nonchiral Luttinger liquid,8,9 electron-electron interactions in the CLL play an essential role and lead to physical properties that can be dra- matically

Geller, Michael R.

331

PHYSICAL REVIEW B 84, 165104 (2011) Aharonov-Bohm interference for a hole in a two-dimensional Ising antiferromagnet

  Physics Websites

Summary: , if the bare hopping and the exchange energy scales are comparable. This contradicts the general view of "defects" (misaligned spins). In dimensions higher than one, the energy cost of this string increases effectively remove (or "heal") pieces of this string of defects are needed to free the hole and allow

Fehske, Holger
2011-01-01

332

[PETO] M. Peshkin A. Tonomura, The AharonovBohm effect , Lecture Notes in Physics, SpringerVerlag, (1989)

  Mathematics Websites

Summary: ) [BA] G. Baym ­ Benjamin ­ Cumming, Lectures on quantum mechanics, Publishing Company Inc. [B­G­O] T. Phys. 119, 315­329, (1988) [HO]1,4 L. Hörmander, The analysis of linear partial differential operators , Springer, tomes 1 à 4 [KU] H. Kumanogo, Pseudo­differential operator of multiple symbol and the Calderòn

Nicoleau, François

333

The three-dimensional Dirac-Oscillator in the presence of Aharonov-Bohm and magnetic monopole potentials

  HEP - Theory (arXiv)

Summary: We study the Dirac equation in 3+1 dimensions with non-minimal coupling to isotropic radial three-vector potential and in the presence of static electromagnetic potential. The space component of the electromagnetic potential has angular (non-central) dependence such that the Dirac equation is completely separable in spherical coordinates. We obtain exact solutions for the case where the three-vector potential is linear in the radial coordinate (Dirac-Oscillator) and the time component of the electromagnetic potential vanishes. The relativistic energy spectrum and spinor eigenfunctions are obtained.

A. D. Alhaidari
2005-01-06

334

Temperature dependence of the Aharonov-Bohm oscillations and the energy spectrum in a single-mode ballistic ring

  Materials Science Websites

Summary: -mode ballistic ring M. Casse´,1,2 Z. D. Kvon,3 G. M. Gusev,4 E. B. Olshanetskii,1,3 L. V. Litvin,3 A. V oscillations in a single mode ballistic ring has been measured. The experimental data is analyzed using to fab- ricate ballistic ring interferometers.2,3 At low temperatures the electron phase coherence

Gusev, Guennady

335

Various Abelian Projections of $SU(2)$ Lattice Gluodynamics and Aharonov-Bohm Effect in the Field Theory

  HEP - Lattice (arXiv)

Summary: We show that in general abelian projection of lattice gluodynamics it is not only monopoles but also strings are present. Both these topological excitations may be responsible for the confinement of color. We illustrate our ideas by some explicit results in the Abelian Higgs model with the Villain action.

M. N. Chernodub; M. I. Polikarpov; M. A. Zubkov
1994-01-24

336

Aharonov-Bohm effect in the presence of dissipative environments Baruch Horovitz1 and Pierre Le Doussal2

  Materials Science Websites

Summary: for the cold atoms necessarily also produces noise. Our problem is then relevant for evaluating the interference am- plitude of the cold atoms in presence of such noise. As an efficient tool for monitoring has been extensively investigated by in- stanton methods,16­18 by renormalization-group RG methods,7

Horovitz, Baruch

337

Supercurrent and multiple singlet-doublet phase transitions of a quantum dot Josephson junction inside an Aharonov-Bohm ring

  Physics Websites

Summary: , however, nonmono- tonically on the coupling strength between the superconductors, causing the system interaction U. As a starting point, the limit of large superconducting energy gaps = is solved analytically of quantum dot Josephson junc- tions is governed by an interplay of superconductivity and the Kondo effect


338

Interplay of Aharonov-Bohm, chirality, and aspect ratio effects in the axial conductance of a nanotube

  CERN Preprints

Summary: A magnetic flux applied along the axis of a nanotube can counteract the effect of the tube chirality and dramatically affect its conductance, leading to a way to determine the chirality of a nanotube. The effect of the applied flux is strongest in the long tube limit where the conductance is (i) either a sequence of sharp $4e^{2}/h$ height peaks located at integer (in units of the flux quantum) values of the flux (for an armchair tube) or (ii) a periodic sequence of pairs of $2e^{2}/h$ height peaks for a chiral tube, with the spacing determined by the chirality. In the short tube limit the conductance takes on the value that gives the universal conductivity of an undoped graphene sheet, with a small amplitude modulation periodic in the flux.

Kolomeisky, Eugene B; Zaidi, Hussain
2011-01-01

339

New formulae for the Aharonov-Bohm wave operators Department of Pure Mathematics and Mathematical Statistics, Centre for Mathe-

  Mathematics Websites

Summary: and Mathematical Statistics, Centre for Mathe- matical Sciences, University of Cambridge, Cambridge, CB3 0WB and on the space dimension. In this paper, we obtain a similar result for the five-parameter family of Hamiltonians of this paper is the following: We first recall the constructions of the five- parameter family of self


340

PUBLISHED ONLINE: 13 DECEMBER 2009 | DOI: 10.1038/NMAT2609 AharonovBohm interference in topological

  Materials Science Websites

Summary: in topological insulator nanoribbons Hailin Peng1,2 *, Keji Lai3,4 *, Desheng Kong1 , Stefan Meister1 , Yulin Chen3,4,5 , Xiao-Liang Qi4,5 , Shou-Cheng Zhang4,5 , Zhi-Xun Shen3,4,5 and Yi Cui1 Topological or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells1

Cui, Yi

341

PUBLISHED ONLINE: 10 JULY 2011 | DOI: 10.1038/NPHYS2034 AharonovBohm interferences from local

  Materials Science Websites

Summary: the observed ripples7­9 and elastic deformations10­15 . The state of the art and an updated list of references, Madrid, Spain, 3Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz 3, Madrid 28049, Spain, 4European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble

Loss, Daniel

342

J. Phys. A: Math. Gen. 32 (1999) 56275641. Printed in the UK PII: S0305-4470(99)04457-1 AharonovBohm beam deflection: Shelankov's formula, exact

  Physics Websites

Summary: for a light beam reflected by a mirror containing a step of height . A theory of this optical phenomenon, Olariuetal 1985), inaccessible magnetic flux diffracts electrons, producing interference fringes whose-dimensional) problem to be studied here. A monochromatic beam of electrons (charge -e) travelling in the r = (x, y

Berry, Michael Victor

343

Propagators weakly associated to a family of Hamiltonians and the adiabatic theorem for the Landau Hamiltonian with a time-dependent Aharonov-Bohm flux

  Mathematical Physics (arXiv)

Summary: We study the dynamics of a quantum particle moving in a plane under the influence of a constant magnetic field and driven by a slowly time-dependent singular flux tube through a puncture. The known adiabatic results do not cover these models as the Hamiltonian has time dependent domain. We give a meaning to the propagator and prove an adiabatic theorem. To this end we introduce and develop the new notion of a propagator weakly associated to a time-dependent Hamiltonian.

J. Asch; I. Hradecky; P. Stovicek
2005-02-25

344

Interference of heavy holes in an Aharonov-Bohm ring Dimitrije Stepanenko,1 Minchul Lee,2 Guido Burkard,3 and Daniel Loss1

  Materials Science Websites

Summary: Burkard,3 and Daniel Loss1 1Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 of the strong spin-orbit coupling of heavy holes confined to the ring,15 and long co- herence length 3 m


345

Matrices de dioeusion pour l'op#rateur de Schr#dinger avec champ magn#tique et ph#nom#ne de AharonovBohm

  Mathematics Websites

Summary: ; ae ? 1, (ie A et V # courte port#e), on montre facilement que H A;V est une perturbation # courte port#e de l'op#rateur de Laplace H 0 = \\Gamma\\Delta et que les op#rateurs d'onde de Moeller (2:1) W, (ae = 1), et donc a priori A est # longue port#e. Cependant, via une condition de jauge appropri

Nicoleau, François

346

Generalized boundary conditions of a spin1/2 particle for the AharonovBohm e#ect combined with a homogeneous magnetic

  Mathematics Websites

Summary: with a homogeneous magnetic field Osamu Ogurisu Department of Computational Science, Kanazawa University, Kanazawa­ teracting the plane at the origin on the background of a homogeneous magnetic field [J. Math. Phys., 43, p e#ect with the background of a homogeneous magnetic field in Ref. [8]: The authors say


347

The Aharonov-Bohm effect for massless Dirac fermions and the spectral flow of Dirac type operators with classical boundary conditions

  HEP - Theory (arXiv)

Summary: We compute, in topological terms, the spectral flow of an arbitrary family of self-adjoint Dirac type operators with classical (local) boundary conditions on a compact Riemannian manifold with boundary under the assumption that the initial and terminal operators of the family are conjugate by a bundle automorphism. This result is used to study conditions for the existence of nonzero spectral flow of a family of self-adjoint Dirac type operators with local boundary conditions in a two-dimensional domain with nontrivial topology. Possible physical realizations of nonzero spectral flow are discussed.

M. I. Katsnelson; V. E. Nazaikinskii
2012-05-24

348

Mesoscopic Fano effect in a quantum dot embedded in an Aharonov-Bohm ring Kensuke Kobayashi, Hisashi Aikawa, Shingo Katsumoto, and Yasuhiro Iye

  Physics Websites

Summary: July 2003; published 5 December 2003 The Fano effect, which occurs through the quantum-mechanical probe to detect a quantum-mechanical phase of travers- ing electrons. DOI: 10.1103/PhysRevB.68 such a system, namely, a QD embedded in one arm of an AB ring. It was found that an electron at least partially

Iye, Yasuhiro

349

On the origin of the minimal coupling rule, and on the possiblity of observing a classical, "Aharonov-Bohm-like" angular momentum

  Quantum Physics (arXiv)

Summary: The minimal coupling rule is "derived" starting from Landau's relativistically invariant classical action for a charge in the presence of classical electromagnetic fields. Experiments are then proposed to see the resulting electromagnetic angular momentum of a classical, "lumpy" charged ring enclosing a solenoid. These classical, macroscopic experiments are similar in spirit to those proposed by Aharonov and Bohm at the quantum level.

Raymond Chiao
2011-04-22

350

Interplay of Coulomb blockade and Aharonov-Bohm resonances in a Luttinger liquid Jari M. Kinaret, Mats Jonson, and Robert I. Shekhter

  Physics Websites

Summary: 1997 We consider a ring of strongly interacting electrons connected to two external leads by tunnel of an electronic system is reduced, a rich variety of new ``mesoscopic'' phenomena becomes experi- mentally leads by tunnel junctions. The tunnel junctions are at positions xL and xR , respectively. The ring

Eggert, Sebastian

351

Crystallization Screens Crystallization Optimization

  Biotechnology Websites

Summary: Crystallization Screens Crystallization Optimization Cryo Screens Phasing www-made solutions in the areas of crystal screening, crystallization optimization, cryo-crystal- lography the researcher to find tailor-made solutions in the areas of crystal screening, crystallization optimization

Lebendiker, Mario

352

Magnetoresistance devices based on single-walled carbon nanotubes Oded Hod and Eran Rabania

  Chemistry Websites

Summary: on the Aharonov-Bohm effect Phys. Rev. 115, 485 1959 . The proposed device is made of a short single-walled carbon to the Aharonov-Bohm effect, and show that by retracting the tip/contacts, so that the coupling to the SWCNT, for example, the conductance is sensitive to the Aharonov-Bohm AB effect.3 The study of the interplay between

Rabani, Eran

353

Geometric Phase for Fermionic Quasiparticles Scattering by Disgyration in Superfluids

  General Relativity & Quantum Cosmology (arXiv)

Summary: We consider a Volovik's analog model for description of a topological defects in a superfluid and we investigate the scattering of quasiparticles in this background. The analog of the gravitational Aharonov-Bohm in this system is found. An analysis of this problem employing loop variables is considered and corroborates for the existence of the Aharonov-Bohm effect in this system. The results presented here may be used to study the Aharonov-Bohm effect in superconductors.

L. C. Garcia de Andrade; A. M. de M. Carvalho; C. Furtado
2004-06-14

354

Matrices de dioeusion pour l'op#rateur de Schr#dinger en pr#sence d'un champ magn#tique Ph#nom#ne de AharonovBohm

  Mathematics Websites

Summary: #tique # longue port#e. Nous estimons la singularit# de l'amplitude de dioeusion sur la diagonale et #tablissons # courte port#e de l'op#rateur de Laplace H 0 = \\Gamma\\Delta et que les op#rateurs d'onde de Moeller (1 due # Isozaki et Kitada, ([6]). Cette approche a l'avantage de fournir des informations sur les

Nicoleau, François

355

Crystal Notes The Crystal

  Biology and Medicine Websites

Summary: . Ordered crystals exist because in their formation they must disorder their surroundings more than Diamond Octahedron octahedral 8 faces Truncated Octahedron octahedral > 8 faces Tetrahedron tetrahedral 35O4 9 2000 corundum Al2O3 10 10,000 diamond C #12;

Meagher, Mary

356

Optical Analog of the Iordanskii Force in a Bose-Einstein Condensate

  Condensed Matter (arXiv)

Summary: A vortex in a Bose-Einstein condensate generates the optical analog of the Aharonov-Bohm effect when illuminated with slow light. In contrast to the original Aharonov-Bohm effect the vortex will exchange forces with the light that lead to a measurable motion of the vortex.

U. Leonhardt; P. Ohberg
2003-05-01

357

Comment on "Coherent Detection of Electron Dephasing'' [arXiv:0909.2197

  Physics (arXiv)

Summary: It is shown that the theoretical result according to which electrons can be reflected because of magnetic flux in the Aharonov-Bohm ring contradicts to the fundamental law of momentum conservation and can not conform with the Aharonov-Bohm effect. Therefore a publication of Phys. Rev. Lett. [arXiv:0909.2197] based on this result can not be correct.

A. V. Nikulov
2010-06-29

358

Optomechanical creation of magnetic fields for photons on a lattice

  Quantum Physics (arXiv)

Summary: We propose using the optomechanical interaction to create artificial magnetic fields for photons on a lattice. The ingredients required are an optomechanical crystal, i.e. a piece of dielectric with the right pattern of holes, and two laser beams with the right pattern of phases. One of the two proposed schemes is based on optomechanical modulation of the links between optical modes, while the other is an lattice extension of optomechanical wavelength-conversion setups. We illustrate the resulting optical spectrum, photon transport in the presence of an artificial Lorentz force, edge states, and the photonic Aharonov-Bohm effect. Moreover, wWe also briefly describe the gauge fields acting on the synthetic dimension related to the phonon/photon degree of freedom. These can be generated using a single laser beam impinging on an optomechanical array.

M. Schmidt; S. Keßler; V. Peano; O. Painter; F. Marquardt
2015-02-26

359

International Crystal Manufacturing

  Physics Websites

Summary: ---------------------------------------------------------------------------16 T26W/T38W Tuning Fork Watch Crystal ------------------------------------------------------------------ 19 SP114 SMD Watch Crystal --------------------------------------------------------------------------------20 SP94 Miniature SMD Watch Crystals

Berns, Hans-Gerd

360

Optomechanical Crystals

  CERN Preprints

Summary: Structured, periodic optical materials can be used to form photonic crystals capable of dispersing, routing, and trapping light. A similar phenomena in periodic elastic structures can be used to manipulate mechanical vibrations. Here we present the design and experimental realization of strongly coupled optical and mechanical modes in a planar, periodic nanostructure on a silicon chip. 200-Terahertz photons are co-localized with mechanical modes of Gigahertz frequency and 100-femtogram mass. The effective coupling length, which describes the strength of the photon-phonon interaction, is as small as 2.9 microns, which, together with minute oscillator mass, allows all-optical actuation and transduction of nanomechanical motion with near quantum-limited sensitivity. Optomechanical crystals have many potential applications, from RF-over-optical communication to the study of quantum effects in mesoscopic mechanical systems.

Eichenfield, Matt; Camacho, Ryan M; Vahala, Kerry J; Painter, Oskar
2009-01-01

361

Gauge invariance and the detection of gravitational radiation

  General Relativity & Quantum Cosmology (arXiv)

Summary: The detection of gravitational radiation raises some subtle issues having to do with the coordinate invariance of general relativity. This paper explains these issues and their resolution by using an analogy with the Aharonov-Bohm effect of quantum mechanics.

David Garfinkle
2005-11-16

362

Disorder-Mediated Electron Valley Resonance in Carbon Nanotube Quantum Dots Andras Palyi1,2

  Materials Science Websites

Summary: in a graphene Aharonov-Bohm ring [3]. However, valley mixing due to edge irregularities of nanostructured gra physics in CNTs, which have a rolled-up and therefore edge-free geometry. In fact, ultraclean CNT quantum


363

INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS A: MATHEMATICAL AND GENERAL J. Phys. A: Math. Gen. 39 (2006) 22872306 doi:10.1088/0305-4470/39/10/004

  Physics Websites

Summary: devices Gilad Rosenberg and Doron Cohen Department of Physics, Ben-Gurion University, Beer-Sheva 84105 an Aharonov­Bohm flux , such that by Faraday's law EMF = - . But there is another way to create a current

Cohen, Doron
2006-01-01

364

Several remarks on ``Comments'' by A. Moroz

  Quantum Physics (arXiv)

Summary: We make a couple of remarks on ``Comments'' due to A. Moroz which were addressed to our recent letter "Differential cross section for Aharonov-Bohm effect with non standard boundary conditions", Europhys. Lett. 44 (1998) 403.

P. Stovicek
1999-06-21

365

Recent Results on the Abelian Projection of Lattice Gluodynamics

  HEP - Lattice (arXiv)

Summary: The abelian projection of lattice gluodynamics is reviewed. The main topics are: abelian and monopole dominance, monopole condensate as the disorder parameter, effective abelian Lagrangian, monopoles in the instanton field, Aharonov -- Bohm effect on the lattice.

M. I. Polikarpov
1996-09-07

366

A rigorous proof for the Landauer-Buttiker formula

  Mathematics Websites

Summary: of transport phenomena through quantum rings, wires or dots (see the monographs [11] and [14]). These nanodevices display several non-trivial effects like Aharonov-Bohm conductance oscilla- tions, quantum Hall


367

Temperature-Dependent Screening of the Edge State around Antidots in the Quantum Hall Regime

  Materials Science Websites

Summary: this issue via study of the Aharonov-Bohm (AB) effect in an antidot system. A quantum antidot, i bound states around the antidot. The magnetotran- sport of antidot systems in the QH regime ubiquitously

Katsumoto, Shingo

368

Interlayer interference in double wells in a tilted magnetic field G. M. Gusev, C. A. Duarte, and T. E. Lamas

  Materials Science Websites

Summary: to Aharonov-Bohm interference effect between cyclotron orbits in different layers. The interplay between as a manifestation of the interference between cyclotron orbits in different quan- tum wells. The peak/value ratio

Gusev, Guennady

369

"Magic Angle Chaotic Precession" (Recurrent Holonomies)

  Physics Websites

Summary: was the first who directly approached the holonomy of gyroscopes; Aharonov-Bohm effect. 3. After 1970s: Wu Rotator (Gyroscope) r = + binder@quanics.com CHAOS2008 O z /d dt = /d dt = /d dt = Precession Spin

Binder, Bernd

370

On Aharonov-Casher bound states

  Quantum Physics (arXiv)

Summary: In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the $\\boldsymbol{\

E. O. Silva; F. M. Andrade; H. Belich; C. Filgueiras
2013-04-23

371

Comment on ``Theoretical Analysis of the Transmission Phase Shift of a Quantum Dot in the Presence of Kondo

  Materials Science Websites

Summary: ) in the Kondo regime, as deduced from placing the QD in a double-slit Aharonov-Bohm interferometer (ABI- ing the double-slit interpretation of the data [A. Aharony and O. Entin-Wohlman, Phys. Rev. B 72

von Delft, Jan

372

Crossover from critical orthogonal to critical unitary statistics at the Anderson transition

  Nonlinear Sciences (arXiv)

Summary: We report a novel scale-independent, Aharonov-Bohm flux controlled crossover from critical orthogonal to critical unitary statistics at the disorder induced metal insulator transition. Our numerical investigations show that at the critical point the level statistics are definitely distinct and determined by fundamental symmetries. The latter is similar to the behavior of the metallic phase known from random matrix theory. The Aharonov-Bohm flux dependent crossover is characteristic of the critical ensemble.

M. Batsch; L. Schweitzer; I. Kh. Zharekeshev; B. Kramer
1996-07-10

373

Toroidal Crystals

  Condensed Matter (arXiv)

Summary: Crystalline assemblages of identical sub-units packed together and elastically bent in the form of a torus have been found in the past ten years in a variety of systems of surprisingly different nature, such as viral capsids, self-assembled monolayers and carbon nanomaterials. In this Letter we analyze the structural properties of toroidal crystals and we provide a unified description based on the elastic theory of defects in curved geometries. We find ground states characterized by the presence of 5-fold disclinations on the exterior of the torus and 7-fold disclinations in the interior. The number of excess disclinations is controlled primarily by the aspect ratio of the torus, suggesting a novel mechanism for creating toroidal templates with precisely controlled valency via functionalization of the defect sites.

Luca Giomi; Mark J. Bowick
2008-01-23

374

VOLUME 88, NUMBER 25 P H Y S I C A L R E V I E W L E T T E R S 24 JUNE 2002 Tuning of the Fano Effect through a Quantum Dot in an Aharonov-Bohm Interferometer

  Materials Science Websites

Summary: electron droplet isolated from its leads by tunnel- ing barriers, has discrete energy levels arising from.256806 PACS numbers: 73.21.La, 72.15.Qm, 73.23.Hk, 85.35.­p When a discrete energy level is embedded the discrete level. In 1961, Fano proposed [1] that in such a system a transi- tion from an arbitrary initial

Katsumoto, Shingo

375

VOLUME 87, NUMBER 25 P H Y S I C A L R E V I E W L E T T E R S 17 DECEMBER 2001 Coherent Coupling of Two Quantum Dots Embedded in an Aharonov-Bohm Interferometer

  Physics Websites

Summary: is fabricated from a negative resist (calixarene) [10] with a dielectric constant of ecax 7.1 [11]. Hereby, the areas of the 2DEG which are below the calixarene are significantly less depleted by voltages which

Ludwig-Maximilians-Universität, München

376

Liquid crystal bilayer wall

  Materials Science Websites

Summary: Liquid crystal bilayer wall Silicified liquid crystal Silica layer Water Water Water Water Surfactant/hexanol Silica layer Figure 1: A sketch of the L3 phase liquid crystal structure, derived from order with long range disorder. The bilayer forming the liquid crystal can then be templated by a silica

Aksay, Ilhan A.

377

Protein crystallization in vivo

  Condensed Matter (arXiv)

Summary: Protein crystallization in vivo provides some fascinating examples of biological self-assembly. Here, we provide a selective survey to show the diversity of functions for which protein crystals are used, and the physical properties of the crystals thatare exploited. Where known, we emphasize how the nature of the protein-protein interactions leads to control of the crystallization behaviour.

Jonathan P. K. Doye; Wilson C. K. Poon
2005-10-03

378

Cylindrical photonic crystals

  MIT - DSpace

Summary: In this thesis, we explore the properties of cylindrical photonic crystal waveguides in which light is confined laterally by the band gap of a cylindrically-layered photonic crystal. We show in particular that axially-uniform ...

Ibanescu, Mihai, 1977-
2005-01-01

379

Protein crystallization Mirjam Leunissen

  Mathematics Websites

Summary: , protein crystal growth has developed into an extensive research field with many applications, for instance (thermodynamic) principles applying to protein crystal growth and the main parameters influencing the process of nucleation processes, crystal growth mechanisms and kinetics is summarized. Concluding this essay

Leunissen, Mirjam

380

Journal of Crystal Growth ] (

  Mathematics Websites

Summary: the nonlinear morphological stability of the self-similar crystals, using a new spectrally accurate 2D boundary that the morphologies of the nonlinearly evolving crystals tend to limiting shapes that evolve self-similarly and depend). #12;morphological evolution of a growing crystal. Because our analysis shows that interactions among

Lowengrub, John

381

Ion Coulomb Crystals

  CERN Preprints

Summary: Ion Coulomb crystals (ICC), formed by atomic ions at low temperatures in radiofrequency and Penning ion traps, are structures that have remarkable properties and many applications. Images of Coulomb crystals are striking and reveal the crystal structure, which arises from a balance between the trapping forces acting on the ions and their mutual Coulomb repulsion. Applications of these structures range from frequency standards and quantum simulation through to measurement of the cross sections of chemical reactions of ions.

Thompson, Richard C
2014-01-01

382

Ion Coulomb Crystals

  Quantum Physics (arXiv)

Summary: Ion Coulomb crystals (ICC), formed by atomic ions at low temperatures in radiofrequency and Penning ion traps, are structures that have remarkable properties and many applications. Images of Coulomb crystals are striking and reveal the crystal structure, which arises from a balance between the trapping forces acting on the ions and their mutual Coulomb repulsion. Applications of these structures range from frequency standards and quantum simulation through to measurement of the cross sections of chemical reactions of ions.

Richard C. Thompson
2014-11-18

383

Function Photonic Crystals

  Physics (arXiv)

Summary: In the paper, we present a new kind of function photonic crystals, which refractive index is a function of space position. Unlike conventional PCs, which structure grow from two materials, A and B, with different dielectric constants $\\epsilon_{A}$ and $\\epsilon_{B}$. By Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we study the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals. By choosing various refractive index distribution function $n(z)$, we can obtain more width or more narrow band gap structure than conventional photonic crystals.

Xiang-Yao Wu; Bai-Jun Zhang; Jing-Hai Yang; Xiao-Jing Liu; Nuo Ba; Yi-Heng Wu; Qing-Cai Wang; Guang-Huai Wang
2012-12-01

384

Arnold Schwarzenegger SINGLE CRYSTAL SILICON

  Energy Storage, Conversion and Utilization Websites

Summary: Arnold Schwarzenegger Governor SINGLE CRYSTAL SILICON SHEET GROWTH Prepared For: California Energy CRYSTAL SILICON SHEET GROWTH EISG AWARDEE ENERGY MATERIALS RESEARCH 132 Chalmers Drive Rochester Hills, MI


385

Quantum extended crystal PDE's

  Math Preprints (arXiv)

Summary: Our recent results on {\\em extended crystal PDE's} are generalized to PDE's in the category $\\mathfrak{Q}_S$ of quantum supermanifolds. Then obstructions to the existence of global quantum smooth solutions for such equations are obtained, by using algebraic topologic techniques. Applications are considered in details to the quantum super Yang-Mills equations. Furthermore, our geometric theory of stability of PDE's and their solutions, is also generalized to quantum extended crystal PDE's. In this way we are able to identify quantum equations where their global solutions are stable at finite times. These results, are also extended to quantum singular (super)PDE's, introducing ({\\em quantum extended crystal singular (super) PDE's}).

Agostino Prástaro
2011-05-16

386

Crystal Electrostatic Energy

  Physics (arXiv)

Summary: It has been shown that to calculate the parameters of the electrostatic field of the ion crystal lattice it sufficient to take into account ions located at a distance of 1-2 lattice spacings. More distant ions make insignificant contribution. As a result, the electrostatic energy of the ion lattice in the alkaline halide crystal produced by both positive and negative ions is in good agreement with experiment when the melting temperature and the shear modulus are calculated. For fcc and bcc metals the ion lattice electrostatic energy is not sufficient to obtain the observed values of these parameters. It is possible to resolve the contradiction if one assumes that the electron density is strongly localized and has a crystal structure described by the lattice delta - function. As a result, positive charges alternate with negative ones as in the alkaline halide crystal. Such delta-like localization of the electron density is known as a model of nearly free electrons.

Alexander Ivanchin
2010-01-24

387

Diffusion in Coulomb Crystals

  Nuclear Theory (arXiv)

Summary: Diffusion in coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants $D$ from molecular dynamics simulations. We find that $D$ for coulomb crystals with relatively soft-core $1/r$ interactions may be larger than $D$ for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ring-like configurations. Here ions "hop" in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from coulomb parameter $\\Gamma=175$ to coulomb parameters up to $\\Gamma=1750$, is fast enough so that the system starts to crystallize during long simulation runs. These results strongly suggest that coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.

J. Hughto; A. S. Schneider; C. J. Horowitz; D. K. Berry
2011-06-07

388

Coolers for Obtaining Crystals

  CiteSeer

Summary: ization rates (see formula (1) of CABRIC et al. 1994) along test tubes. Defect "flowing" towards test tube walls is regulated by the angle between the test tube axis B. CABRIC, T. PAVLOVIC*, M. RISTIC Faculty of Sciences, Kragujevac, Yugoslavia *Faculty of Philosophy, Nis, Yugoslavia Coolers for Obtaining Crystals 130 B. CABRIC et al.: Coolers for Obtaining Crystals and crystallization rate direction (inclining test tube (Fig. 1)). The temperature gradient is regulated by the distance (b), which is performed by moving part of the cooler ("cold bench"). Tamman's test tubes of various shapes and dimensions (WILKE) can be mounted on the rings, i.e. simultaneously tested. By varying the shape and dimensions of the movable part of the cooler, a family of "cold bench" can be modelled for tests in a wider range of temperature gradients and crystallization rate in

B. Cabric; T. Pavlovic; M. Ristic

389

Crystallization: Colloidal suspense

  Condensed Matter (arXiv)

Summary: According to classical nucleation theory, a crystal grows from a small nucleus that already bears the symmetry of its end phase - but experiments with colloids now reveal that, from an amorphous precursor, crystallites with different structures can develop.

László Gránásy; Gyula I. Tóth
2014-07-14

390

Magnetic Response in the Holographic Insulator/Superconductor Transition

  HEP - Theory (arXiv)

Summary: We study the magnetic response of holographic superconductors exhibiting an insulating "normal" phase. These materials can be realized as a CFT compactified on a circle, which is dual to the AdS Soliton geometry. We study the response under i) magnetic fields and ii) a Wilson line on the circle. Magnetic fields lead to formation of vortices and allows one to infer that the superconductor is of type II. The response to a Wilson line is in the form of Aharonov-Bohm-like effects. These are suppressed in the holographic conductor/superconductor transition but, instead, they are unsuppressed for the insulator case. Holography, thus, predicts that generically insulators display stronger Aharonov-Bohm effects than conductors. In the fluid-mechanical limit the AdS Soliton is interpreted as a supersolid. Our results imply that supersolids display unsuppressed Aharonov-Bohm (or "Sagnac") effects - stronger than in superfluids.

Marc Montull; Oriol Pujolàs; Alberto Salvio; Pedro J. Silva
2012-05-03

391

New Views of Crystal Symmetry

  CERN Preprints

Summary: Already Hermann Grassmann's father Justus (1829, 1830) published two works on the geometrical description of crystals, influenced by the earlier works of C.S. Weiss (1780-1856) on three main crystal forces governing crystal formation. In his 1840 essay on the derivation of crystal shapes from the general law of crystal formation Hermann established the notion of a three-dimensional vectorial system of forces with rational coefficients, that represent the interior crystal structure, regulate its formation, its shape and physical behavior. In the Ausdehnungslehre 1844 (Paragraph 171) he finally writes: I shall conclude this presentation by one of the most beautiful applications which can be made of the science treated, i.e. the application to crystal figures (Scholz, 1996). The geometry of crystals thus certainly influenced the Ausdehnungslehre. In this paper we see how Grassmann's work influenced Clifford's creation of geometric algebras, which in turn leads to a new geometric description of crystal symmetry s...

Hitzer, Eckhard
2013-01-01

392

Charge screening in the Higgs phase of Chern-Simons electrodynamics

  HEP - Theory (arXiv)

Summary: Though screened at large distances, a point-like electric charge can still participate in a long-range electromagnetic interaction in the Higgs phase, namely that with the Aharonov-Bohm field produced by a localized magnetic flux. We show that this follows from the fact that the screening charge, induced in the presence of a Higgs condensate, does not interact with the Aharonov-Bohm field. The same phenomenon occurs, if a Chern-Simons term is incorporated in the action. This observation provides a physical basis for the recently proposed classification of the superselection sectors of this model in terms of a quasi-Hopf algebra.

F. Alexander Bais; A. Morozov; M. de Wild Propitius
1993-03-26

393

Hartman effect in presence of Aharanov Bohm flux

  Quantum Physics (arXiv)

Summary: The Hartman effect for the tunneling particle implies the independence of group delay time on the opaque barrier width, with superluminal velocities as a consequence. This effect is further examined on a quantum ring geometry in the presence of Aharonov-Bohm flux. We show that while tunneling through an opaque barrier the group delay time for given incident energy becomes independent of the barrier thickness as well as the magnitude of the flux. The Hartman effect is thereby extended beyond one dimension and in the presence of Aharonov-Bohm flux.

Swarnali Bandopadhyay; Raishma Krishnan; A. M. Jayannavar
2003-12-03

394

Interferometry using spatial adiabatic passage in quantum dot networks

  Quantum Physics (arXiv)

Summary: We show that techniques of spatial adiabatic passage can be used to realise an electron interferometer in a geometry analogous to a conventional Aharonov-Bohm ring, with transport of the particle through the device modulated using coherent transport adiabatic passage. This device shows an interesting interplay between the adiabatic and non-adiabatic behaviour of the system. The transition between non-adiabatic and adiabatic behaviour may be tuned via system parameters and the total time over which the protocol is enacted. Interference effects in the final state populations analogous to the electrostatic Aharonov-Bohm effect are observed.

Lenneke M Jong; Andrew D. Greentree
2009-12-16

395

Nonrelativistic molecular models under external magnetic and AB flux fields

  Quantum Physics (arXiv)

Summary: By using the wave function ansatz method, we study the energy eigenvalues and wave function for any arbitrary $m$-state in two-dimensional Schr\\"{o}dinger wave equation with various power interaction potentials in constant magnetic and Aharonov-Bohm (AB) flux fields perpendicular to the plane where the interacting particles are confined. We calculate the energy levels of some diatomic molecules in the presence and absence of external magnetic and AB flux fields using different potential models. We found that the effect of the Aharonov-Bohm field is much as it creates a wider shift for $m\

Sameer M. Ikhdair; Babatunde J. Falaye; Majid Hamzavi
2014-12-21

396

A classical analog to topological non-local quantum interference effect

  Quantum Physics (arXiv)

Summary: The two main features of the Aharonov-Bohm effect are the topological dependence of accumulated phase on the winding number around the magnetic fluxon, and non-locality -- local observations at any intermediate point along the trajectories are not affected by the fluxon. The latter property is usually regarded as exclusive to quantum mechanics. Here we show that both the topological and non-local features of the Aharonov-Bohm effect can be manifested in a classical model that incorporates random noise. The model also suggests new types of multi-particle topological non-local effects which have no quantum analog.

Y. Aharonov; S. Popescu; B. Reznik; A. Stern
2003-11-23

397

Which-path interferometry using spatial adiabatic passage in quantum dot networks

  CERN Preprints

Summary: We show that techniques of spatial adiabatic passage can be used to realise an electron interferometer in a geometry analogous to a conventional Aharonov-Bohm ring, with transport of the particle through the device modulated using coherent transport adiabatic passage. This device shows an interesting interplay between the adiabatic and non-adiabatic behaviour of the system. The transition between non-adiabatic and adiabatic behaviour may be tuned via system parameters and the total time over which the protocol is enacted. Interference effects in the final state populations analogous to the electrostatic Aharonov-Bohm effect are observed.

Jong, Lenneke M
2009-01-01

398

Deformed Skyrme Crystals

  HEP - Theory (arXiv)

Summary: The Skyrme crystal, a solution of the Skyrme model, is the lowest energy-per-charge configuration of skyrmions seen so far. Our numerical investigations show that, as the period in various space directions is changed, one obtains various other configurations, such as a double square wall, and parallel vortex-like solutions. We also show that there is a sudden "phase transition" between a Skyrme crystal and the charge 4 skyrmion with cubic symmetry as the period is gradually increased in all three space directions.

J. Silva Lobo
2010-10-04

399

Generalized Skyrme Crystals

  HEP - Theory (arXiv)

Summary: This letter deals with triply-periodic (crystalline) solutions in a family of Skyrme systems, namely where the field takes values in the squashed 3-sphere. The family includes the standard Skyrme model (round 3-sphere), and the Skyrme-Faddeev case (maximal squashing). In the round case, the lowest-energy crystal is the well-known cubic lattice of half-skyrmions; but in the squashed case the minimal-energy crystal structures turn out to be different. We describe some of the solutions that arise, including arrays of vortices and multi-sheeted structures.

J. Silva Lobo; R. S. Ward
2010-12-18

400

Photonic crystals Fabrication of Tunable Spherical Colloidal Crystals

  Physics Websites

Summary: Photonic crystals Fabrication of Tunable Spherical Colloidal Crystals Immobilized in Soft Hydrogels** Toshimitsu Kanai, Daeyeon Lee, Ho Cheung Shum, and David A. Weitz* Spherical colloidal crystals are three-dimensional periodic arrays of monodisperse colloidal particles with a spherical geometry.[1] The spatial periodicity


401

Protein crystallization: from purified protein to diffraction-quality crystal

  Biology and Medicine Websites

Summary: , the first bottleneck in the procedure is at the protein purification stage.The problem is how to obtain to crystallization by removal of flexible tails and interdo- main regions,as well as random or rational mutagenesis by influencing the crystallization process. Setting up initial trials Finding crystallization conditions

Cai, Long

402

Simulation of Crystal Extraction Experiments

  CiteSeer

Summary: We discuss the simulation methods and results for the crystal extraction experiments performed recently at the high energy accelerators. Possible future applications of the crystal channeling technique are considered. 1

Valery M. Biryukov

403

Simulation of crystal extraction experiments

  HEP - Experiment (arXiv)

Summary: We discuss the simulation methods and results for the crystal extraction experiments performed recently at the high energy accelerators. Possible future applications of the crystal channeling technique are considered.

Valery M. Biryukov
2001-10-29

404

Colloids at liquid crystal interfaces 

  Edinburgh, University of - Research Archive

Summary: This thesis presents a study of colloidal particles dispersed in thermotropic liquid crystals. It has a specific focus on colloids in the presence of an interface between the liquid crystal and an isotropic fluid. Three ...

Pawsey, Anne Claire
2014-06-28

405

SINGLE CRYSTAL SURFACE ENGINEERING

  Materials Science Websites

Summary: ENGINEERINGSX - SURFACE ENGINEERING · SX superalloys are generally used for HPT turbine blades. · MechanicalCrAlY coating. · Ni has high crystal (E) anisotropy ® incompatibility stresses in thermal cycling ® premature SOLIDIFICATION CONDITIONS bottom surface 50% #12;EPFL COMBINATION OF PARAMETERS CHARACTERISTIC

Cambridge, University of

406

Lattice-Gas Crystallization

  CiteSeer

Summary: This paper presents a new lattice-gas method for molecular dynamics modeling. A mean field treatment is given and is applied to a linear stability analysis. Exact numerical simulations of the solid-phase crystallization is presented, as is a finite-temperature multiphase liquid-gas system. The

Jeffrey Yepez
1994-01-01

407

Nondiffractive sonic crystals

  Physics (arXiv)

Summary: We predict theoretically the nondiffractive propagation of sonic waves in periodic acoustic media (sonic crystals), by expansion into a set of plane waves (Bloch mode expansion), and by finite difference time domain calculations of finite beams. We also give analytical evaluations of the parameters for nondiffractive propagation, as well as the minimum size of the nondiffractively propagating acoustic beams.

Isabel Perez-Arjona; Victor J. Sanchez-Morcillo; Javier Redondo; Victor Espinosa; Kestutis Staliunas
2006-06-02

408

Crystal Growing The "Touch"

  Biology and Medicine Websites

Summary: battle leads to a condition called supersaturation, a condition where the concentration of the solution is to reach this condition and to keep it stable while the crystals slowly form. Unfortunately the primary sources of dust near your bench. Run a clean filtered compressed air line or purchase compressed

Meagher, Mary

409

Photonic Crystal: FIB etching

  Physics Websites

Summary: Waveguide 100 m×2.5 mm The patterned area is about 4 m×100 m photonic crystal filter is formed by a line defect of transmission All optical filter, switch Time-resolved evanescent field coupling measurement filter, switch with ultrafast time response is realized . Time Response #12;M4M4

Wang, Wei Hua

410

Liquid crystal lasers Andrii Varanytsia

  Chemistry Websites

Summary: Liquid crystal lasers Andrii Varanytsia Class: LC Optics and Photonics, Spring 2012 Instructor: Professor Peter Palffy-Muhoray 1 #12;Outline · Organic dye lasers and distributed feedback lasers · Liquid crystal laser · Methods of control and tuning liquid crystal laser emission · Methods of emission

Palffy-Muhoray, Peter

411

Contribution of crystal-impeller and crystal-crystal collisions to secondary nucleation

  CiteSeer

Summary: A secondary nucleation model mainly based on the findings of Ottens (1973) and Evans (1974) considering both crystal-impeller collisions and crystal-crystal collisions was investigated using experimental data obtained from two crystallizers, a 22-liter Draft Tube (DT) crystallizer and an 1100-liter Draft Tube Baffled (DTB) crystallizer, which are both operated continuously in an evaporative mode for the crystallization of ammonium sulfate. Since the two crystallizer types differ in scale and configuration, not only the effect of the impeller frequency but also the effect of scale on the crystal size distribution (CSD) could be investigated. The CSD-prediction obtained using dynamic process simulations is consistent with the measured data for all investigated experiments. Not only the changes in the CSD due to different impeller frequencies, but also the changes due to scale and configuration are well described and model is able to capture the sustained cyclic behavior in DTB crystallizer. It was found that three model parameters i.e. the number of nuclei per unit energy, the lower bound of integration for the crystal-impeller and for the crystal-

A. Imran; E. Wolf; H. J. M. Kramer; P. J. Jansens

412

Entangling Atoms in Photonic Crystals

  Quantum Physics (arXiv)

Summary: We propose a method for entangling a system of two-level atoms in photonic crystals. The atoms are assumed to move in void regions of a photonic crystal. The interaction between the atoms is mediated either via a defect mode or via resonant dipole-dipole interaction. We show that these interactions can produce pure entangled atomic states. We analyze the problem with parameters typical for currently existing photonic crystals and Rydberg atoms. We show that the atoms can emerge from photonic crystals in entangled states. Depending on the linear dimensions of the crystal and on their velocity of the entangled atoms can be separated by tens of centimeters.

Martin Konopka; Vladimir Buzek
1999-01-26

413

Optimization of crystal extraction experiment

  HEP - Experiment (arXiv)

Summary: Using a computer model for the crystal extraction, we investigate the bent-crystal parameters optimal for the extraction experiment. The optimal crystal curvature is found to be near 1 GeV/cm (for pv/R), i.e. a factor of 2--3 higher than for the crystal application in beam lines. An influence of the accelerator optics on extraction is discussed. A possibility of using the high-Z crystals for extraction is considered. The simulations for the ongoing experiments at the CERN-SPS and the Fermilab Tevatron, and for the proposed extraction at LHC, are presented.

Valery Biryukov
2001-10-11

414

Crystalizing the genetic code

  CERN Preprints

Summary: New developments are presented in the framework of the model introduced by the authors in refs. [1,2] and in which nucleotides as well as codons are classified in crystal bases of the quantum group U_q(sl(2)+sl(2)) in the limit q -> 0. An operator which gives the correspondence between the amino-acids and the codons is now obtained for any known genetic code. The free energy released by base pairing of dinucleotides as well as the relative hydrophilicity and hydrophobicity of the dinucleosides are also computed. For the vertebrate series, a universal behaviour in the ratios of codon usage frequencies is put in evidence and is shown to fit nicely in our model. Then a first attempt to represent the mutations relative to the deletion of a pyrimidine by action of a suitable crystal spinor operator is proposed. Finally recent theoretical descriptions are reviewed and compared with our model.

Frappat, L; Sorba, Paul
2000-01-01

415

Cracks Cleave Crystals

  Condensed Matter (arXiv)

Summary: The problem of finding what direction cracks should move is not completely solved. A commonly accepted way to predict crack directions is by computing the density of elastic potential energy stored well away from the crack tip, and finding a direction of crack motion to maximize the consumption of this energy. I provide here a specific case where this rule fails. The example is of a crack in a crystal. It fractures along a crystal plane, rather than in the direction normally predicted to release the most energy. Thus, a correct equation of motion for brittle cracks must take into account both energy flows that are described in conventional continuum theories and details of the environment near the tip that are not.

Michael Marder
2004-03-05

416

Classical Time Crystals

  Mathematical Physics (arXiv)

Summary: We consider the possibility that classical dynamical systems display motion in their lowest energy state, forming a time analogue of crystalline spatial order. Challenges facing that idea are identified and overcome. We display arbitrary orbits of an angular variable as lowest-energy trajectories for nonsingular Lagrangian systems. Dynamics within orbits of broken symmetry provide a natural arena for formation of time crystals. We exhibit models of that kind, including a model with traveling density waves.

Alfred Shapere; Frank Wilczek
2012-07-12

417

Classical Time Crystals

  CERN Preprints

Summary: We consider the possibility that classical dynamical systems display motion in their lowest energy state, forming a time analogue of crystalline spatial order. Challenges facing that idea are identified and overcome. We display arbitrary orbits of an angular variable as lowest-energy trajectories for nonsingular Lagrangian systems. Dynamics within orbits of broken symmetry provide a natural arena for formation of time crystals. We exhibit models of that kind, including a model with traveling density waves.

Shapere, Alfred
2012-01-01

418

Ultraviolet photonic crystal laser

  CERN Preprints

Summary: We fabricated two dimensional photonic crystal structures in zinc oxide films with focused ion beam etching. Lasing is realized in the near ultraviolet frequency at room temperature under optical pumping. From the measurement of lasing frequency and spatial profile of the lasing modes, as well as the photonic band structure calculation, we conclude that lasing occurs in the strongly localized defect modes near the edges of photonic band gap. These defect modes originate from the structure disorder unintentionally introduced during the fabrication process.

Wu, X; Liu, X; Li, S; Dravid, V P; Chang, R P H; Cao, H
2004-01-01

419

Consistently melting crystals

  HEP - Theory (arXiv)

Summary: Recently Ooguri and Yamazaki proposed a statistical model of melting crystals to count BPS bound states of certain D-brane configurations on toric Calabi--Yau manifolds [arXiv:0811.2801]. This construction relied on a set of consistency conditions on the corresponding brane tiling, and in this note I show that these conditions are satisfied for any physical brane tiling; they follow from the conformality of the low energy field theory on the D-branes. As a byproduct I also provide a simple direct proof that any physical brane tiling has a perfect matching.

Klaus Larjo
2009-02-04

420

Canonical Transformations in Crystals

  Mathematical Physics (arXiv)

Summary: The space representations of linear canonical transformations were studied by Moshinsky and Quesne in 1972. For a few decades, the bilinear hamiltonian remained as the only exactly solvable representative for such problems. In this work we show that the Mello-Moshinsky equations can be solved exactly for a class of problems with discrete symmetry, leading to exact propagators for Wannier-Stark ladders in one and two dimensional crystals. We give a detailed study for a particle in a triangular lattice under the influence of a time-dependent electric field. A more general set of Mello-Moshinsky equations for arbitrary lattices is presented.

Emerson Sadurní
2013-08-14

421

Crystal engineering: A brief overview

  CiteSeer

Summary: Abstract. Crystal structures of organic and metal-organic compounds have been determined in enor-mous numbers over the past century, and at the time of writing this review, the Cambridge Structural Database has just crossed the half million mark. The possibility of designing a particular crystal packing is, however, of more recent origin and the subject of crystal engineering has addressed this possibility, more or less systematically, during the past 30 years. Crystal engineering demands a detailed and thor-ough knowledge of intermolecular interactions, which act as the supramolecular glue that binds mole-cules into crystals. It also requires systematic strategies for the design of a crystal, the architectural blueprint as it were. Finally, this enterprise needs to be geared towards a useful property in that the crys-tal that is being designed is a functional one. All these features of the subject are directly or indirectly connected with the fact that there is a very large database of known crystal structures that is available to the crystal engineer. This review attempts to briefly survey the current scenario in this expanding subject.

Gautam R Desiraju

422

Acoustic properties of colloidal crystals

  Condensed Matter (arXiv)

Summary: We present a systematic study of the frequency band structure of acoustic waves in crystals consisting of nonoverlapping solid spheres in a fluid. We consider colloidal crystals consisting of polystyrene spheres in water, and an opal consisting of close-packed silica spheres in air. The opal exhibits an omnidirectional frequency gap of considerable width; the colloidal crystals do not. The physical origin of the bands are discussed for each case in some detail. We present also results on the transmittance of finite slabs of the above crystals.

I. E. Psarobas; R. Sainidou; N. Stefanou; A. Modinos
2001-10-30

423

MODELING LIQUID CRYSTAL MATERIALS ANDMODELING LIQUID CRYSTAL MATERIALS AND PROCESSES IN BIOLOGICAL SYSTEMSPROCESSES IN BIOLOGICAL SYSTEMS

  Geosciences Websites

Summary: MODELING LIQUID CRYSTAL MATERIALS ANDMODELING LIQUID CRYSTAL MATERIALS AND PROCESSES IN BIOLOGICAL Device Modeling #12;Biological Liquid Crystals Nucleic Acids Collagen Silks CarbohydratesLipids & membranes Proteins ·T. Rizvi, Liquid crystalline biopolymers, J. Molecular Liquids 2003. #12;Liquid Crystal

Maryland at College Park, University of

424

Mesoscopic Physics SK2700 Home work assignments will be handed out every week, due the following week.

  Materials Science Websites

Summary: single JJ Impedance of environment Own Notes, articles Lecture 14 Cooper Pair box, Cooper Pair Transistor invariant phase and Aharonov-Bohm effect Data Chapter 5, Physics Today article, Wasburn and Webb Lecture 8: Grabert and Devoret introduction, Esteve article. Lecture 12 Josephson effect Classical dynamics

Haviland, David

425

International Journal of Modern Physics B Vol. 23, Nos. 12 & 13 (2009) 26032606

  Materials Science Websites

Summary: @romeo.if.usp.br Received 15 October 2008 We have studied Shubnikov de Haas oscillations and the quantum Hall effect in Ga analyzed and interpreted as the Aharonov-Bohm effect, in real and momen- tum space. For example, magnetic in different layers, which leads to oscillations of the effective interlayer tunneling amplitude.3

Gusev, Guennady
2009-01-01

426

Coulomb Blockade and Kondo Effect in a Quantum Hall Antidot H.-S. Sim,1

  Materials Science Websites

Summary: Coulomb Blockade and Kondo Effect in a Quantum Hall Antidot H.-S. Sim,1 M. Kataoka,2 Hangmo Yi,1 N quantization, and their effective spin fluctuation can result in Coulomb blockade, h=2e Aharonov-Bohm oscillations, and the Kondo effect. The resultant conductance is in qualitative agreement with recent

Choi, Mahn-Soo

427

Israeli Conference on Plasma Science and Applications Israel Plasma Science and Technology Association

  Plasma Physics and Fusion Websites

Summary: of plasma waves via formation of holes in phase space 14:45 - 15:00 A. Yahalom, Ariel Aharonov Bohm in a Vacuum Arc with a Black Body Electrode Configuration 16:35 - 16:50 E. Gidalevich and R. L. Boxman, TAU


428

www.aspbs.com/enn odeling of arbon-Based Nanojunctions

  Physics Websites

Summary: transform the tube from a metal into rnp_iY~,n semiconductor and vice versa. This was addressed a model Aharonov-Bohm oscillations [26] of the bandgap due to a flux the tube [27]. It has also been shown, and (d) controlled switches. PROPERTIES CARBON NANOTUBES (CNTs) In this we review the electronic

Cuniberti, Gianaurelio

429

VOLUME 74, NUMBER 3 P H Y S I C A L R E V I E W L E T T E R S 16 JANUARY 1995 Observation of Quantum Interference in a Phase-Coherent Two-Dimensional Superlattice

  Physics Websites

Summary: -2600 GA Delft, The Netherlands C. T. Foxon Philips Research Laboratories, Redhill, Surrey RH1 5HA. In low magnetic fields (B , 1 T) conductance minima are measured due to localization of electron orbits. Superimposed on these minima, Aharonov-Bohm oscillations are observed with periods in B which are submultiples


430

PERSISTENT CURRENTS IN A KONDO RING H.-P. Eckle, 1;2 H. Johannesson, 3 and C. A. Sta ord 2;4

  Materials Science Websites

Summary: . The system consists of electrons in a one-dimensional ring threaded by an Aharonov-Bohm ux #8;, coupled via where electrons in a one-dimensional (1D) ring threaded by an AB ux are coupled via antiferromagnetic exchange to a localized electron, representing a magnetic impurity or quantum dot. A detailed analysis

Stafford, Charles

431

*Corresponding author. E-mail address: tfkhj@fy.chalmers.se (H. Johannesson)

  Materials Science Websites

Summary: threaded by spin-dependent Aharonov}Bohm/Casher #uxes, and coupled via an antiferromagnetic exchange model where electrons in a one-dimensional (1D) ring threaded by a magnetic #ux and a charged string or an ultrasmall quan- tum dot. A detailed analysis shows that this model can be mapped onto the integrable Kondo

Stafford, Charles

432

Remarks about Hardy inequalities on metric trees

  Mathematical Physics (arXiv)

Summary: We find sharp conditions on the growth of a rooted regular metric tree such that the Neumann Laplacian on the tree satisfies a Hardy inequality. In particular, we consider homogeneous metric trees. Moreover, we show that a non-trivial Aharonov-Bohm magnetic field leads to a Hardy inequality on a loop graph.

Tomas Ekholm; Rupert L. Frank; Hynek Kovarik
2007-11-13

433

Interference of Charged Particles in a Vector Potential with Vanishing Magnetic Field

  HEP - Phenomenology (arXiv)

Summary: An interference experiment in a magnetic field free region with non vanishing vector potential created by two perpendicularly intersecting planes carrying uniform currents is discussed. The relation of this configuration to the Aharonov-Bohm potential is examined. An experimental set up which is finite in the direction of the electronic motion is studied.

I. H. Duru
1997-04-29

434

Nuclear Physics B 386 (1992) 27--42 P H VS I C S B North-Holland ________________

  Physics Websites

Summary: of Technology, Pasadena, CA 91125, USA Received 23 December 1991 (Revised 25 May 1992) Accepted for publication 26 May 1992 We analyze the charges carried by loops of string in models with non-abelian local of the Aharonov--Bohm interaction of the loop with another string. We describe the process of charge detection

Preskill, John
1992-01-01

435

Non-Abelian Gauge Configuration with a Magnetic Field Concentrated at a Point

  HEP - Theory (arXiv)

Summary: A specific SU(2) gauge configuration yielding a magnetic field concentrated at a point is investigated. Its relation to the Aharonov-Bohm gauge potential and its cohomological meaning in a three dimensional space are clarified. Quantum mechanics of a spinning particle in such a gauge configuration is briefly discussed.

Minoru Hirayama; Takeshi Hamada; Masafumi Hasegawa
1997-11-10

436

Testing Atom and Neutron Neutrality with Atom Interferometry

  HEP - Experiment (arXiv)

Summary: We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10^{-28}e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10^{-28}e, 7 orders of magnitude below current bounds.

Asimina Arvanitaki; Savas Dimopoulos; Andrew A. Geraci; Jason Hogan; Mark Kasevich
2007-11-29

437

AB and Berry phases for a quantum cloud of charge

  HEP - Theory (arXiv)

Summary: We investigate the phase accumulated by a charged particle in an extended quantum state as it encircles one or more magnetic fluxons, each carrying half a flux unit. A simple, essentially topological analysis reveals an interplay between the Aharonov-Bohm phase and Berry's phase.

Y. Aharonov; S. Coleman; A. S. Goldhaber; S. Nussinov; S. Popescu; B. Reznik; D. Rohrlich; L. Vaidman
1993-12-15

438

A New Interpretation of Flux Quantization Department of Physics, University of Puerto Rico

  Mathematics Websites

Summary: 00681 Abstract We study the e#ect of Aharonov­Bohm flux on the superconducting state in metallic in the free energy of the superconducting state (relative to that of normal state) as a function of the flux fascinating properties of superconducting states. This phenomenon was found by Deaver and Fairbank 1 and Doll


439

THESIS FOR THE DEGREE OF LICENTIATE OF PHILOSOPHY On the two-dimensional Pauli operator

  Mathematics Websites

Summary: different two-dimensional self-adjoint Pauli operators corresponding to a singular magnetic field with a finite number of Aharonov-Bohm solenoids. In the first paper the Pauli operator is defined via particle, moving in a plane, affected by a magnetic field B orthogonal to the plane, is described

Patriksson, Michael

440

Quantum Interference in Radial Heterostructure Nanowires

  Materials Science Websites

Summary: Core/shell heterostructure nanowires are one of the most interesting mesoscopic systems potentially of both the Aharonov-Bohm (h/e) and the Altshuler-Aronov-Spivak (h/2e) oscillations in radial core oscillation to high-field h/e oscillation. The relationship between the oscillation period and the core width

Choi, Mahn-Soo

441

Yambo:Yambo: present, past and futurepresent, past and future

  Physics Websites

Summary: . Chem Phys. 131131, 084102(2009), 084102(2009) #12;Magnetic systems: Ab-initio Aharonov-Bohm effect Molecules on surfaces #12;Magnetic systems: Kerr effect Kerr parameters in Iron and Cobalt D. Sangalli et al as it is done in OCTOPUS or RT-TDDFT/SIESTA codes. Quasi-monocromatich-field p-nitroaniline Y.Takimoto, Phd

Marini, Andrea

442

Global aspects of gravitomagnetism

  General Relativity & Quantum Cosmology (arXiv)

Summary: We consider global properties of gravitomagnetism by investigating the gravitomagnetic field of a rotating cosmic string. We show that although the gravitomagnetic field produced by such a configuration of matter vanishes locally, it can be detected globally. In this context we discuss the gravitational analogue of the Aharonov-Bohm effect.

A. Barros; V. B. Bezerra; C. Romero
2003-07-12

443

Jens Bardarson Tuesday, June 15

  Plasma Physics and Fusion Websites

Summary: -Bohm Oscillations in Disordered Topological Insulator Nanowires" A direct signature of electron transport at the metallic surface of a topological insulator is the Aharonov-Bohm oscillation observed in a recent study of $\\phi_0$ but a minimum at zero flux due to a nontrivial Berry phase in topological insulators

Lathrop, Daniel P.

444

EPL, 85 (2009) 57008 www.epljournal.org doi: 10.1209/0295-5075/85/57008

  Chemistry Websites

Summary: distributions of electron transfers through quantum dot Aharonov-Bohm interferometers S. Welack1(a) , S. Mukamel2 and YiJing Yan1(b) 1 Department of Chemistry, Hong Kong University of Science and Technology November 2008; accepted in final form 13 February 2009 published online 19 March 2009 PACS 73.63.Kv

Mukamel, Shaul
2009-01-01

445

Entanglement Witnesses from Single-Particle Interference

  Quantum Physics (arXiv)

Summary: We describe a general method of realizing entanglement witnesses in terms of the interference pattern of a single quantum probe. After outlining the principle, we discuss specific realizations both with electrons in mesoscopic Aharonov-Bohm rings and with photons in standard Young's double-slit or coherent-backscattering interferometers.

T. Scholak; F. Mintert; C. A. Müller
2008-09-23

446

Available online at www.sciencedirect.com Physica E 22 (2004) 365368

  Physics Websites

Summary: .elsevier.com/locate/physe Quantum oscillation and decoherence in triangular antidot lattice M. Ueki, A. Endo, S. Katsumoto, Y. Iye oscillation phenomena in triangular antidot lattice have been investigated. Altshuler­Aronov­Spivak oscillations and Aharonov­Bohm (AB)-type oscillations are observed at low magnetic ÿeld, and AB

Iye, Yasuhiro
2004-01-01

447

A Brief Note on the Magnetic Effects of the Electron

  Physics (arXiv)

Summary: In this paper it is shown that a recent formulation of the electron in terms of a Kerr-Newman type metric, exhibits a short range magnetic effect, as indeed has been observed at Cornell, and also an Aharonov-Bohm type of an effect.

B. G. Sidharth
2000-04-20

448

Hidden supersymmetry in quantum bosonic systems

  Nuclear Theory (arXiv)

Summary: We show that some simple well studied quantum mechanical systems without fermion (spin) degrees of freedom display, surprisingly, a hidden supersymmetry. The list includes the bound state Aharonov-Bohm, the Dirac delta and the Poschl-Teller potential problems, in which the unbroken and broken N=2 supersymmetry of linear and nonlinear (polynomial) forms is revealed.

Francisco Correa; Mikhail S. Plyushchay
2006-12-11

449

Crystal Growth Platonic Gold Nanocrystals**

  Chemistry Websites

Summary: of shape control has started to revitalize the centuries-old metal colloidal synthesis. Nano- particles of various shapes[3­5] (rods,[6­9] wires,[10­12] prisms,[13­19] cubes[20,21] ), particularly those of silver platonic nano- crystals) with high yield and good uniformity. These nano- crystals have the perfect

Yang, Peidong

450

Two classes of unconventional photonic crystals

  MIT - DSpace

Summary: This thesis concerns two classes of photonic crystal that differ from the usual solid-state dielectric photonic crystals studied in optical physics. The first class of unconventional photonic crystal consists of atoms bound ...

Chong, Y. D. (Yi Dong)
2008-01-01

451

Continuous Plug Flow Crystallization of Pharmaceutical Compounds

  MIT - DSpace

Summary: Crystallization processes in the pharmaceutical industry are usually designed to obtain crystals with controlled size, shape, purity, and polymorphic form. Knowledge of the process conditions required to fabricate crystals ...

Alvarez, Alejandro J.

452

Taub-NUT Crystal

  HEP - Theory (arXiv)

Summary: We consider the Gibbons-Hawking metric for a three-dimensional periodic array of multi-Taub-NUT centers, containing not only centers with a positive NUT charge but also ones with a negative NUT charge. The latter are regarded as representing the asymptotic form of the Atiyah-Hitchin metric. The periodic arrays of Taub-NUT centers have close parallels with ionic crystals, where the Gibbons-Hawking potential plays the role of the Coulomb static potential of the ions, and are similarly classified according to their space groups. After a periodic identification and a Z2 projection, the array is transformed by T-duality to a system of NS5-branes with the SU(2) structure, and a further standard embedding yields, though singular, a half-BPS heterotic 5-brane background with warped compact transverse dimensions. A discussion is given of the possibility of probing the singular geometry by two-dimensional gauge theories.

Harunobu Imazato; Shun'ya Mizoguchi; Masaya Yata
2011-07-18

453

Taub-NUT Crystal

  CERN Preprints

Summary: We consider the Gibbons-Hawking metric for a three-dimensional periodic array of multi-Taub-NUT centers, containing not only centers with a positive NUT charge but also ones with a negative NUT charge. The latter are regarded as representing the asymptotic form of the Atiyah-Hitchin metric. The periodic arrays of Taub-NUT centers have close parallels with ionic crystals, where the Gibbons-Hawking potential plays the role of the Coulomb static potential of the ions, and are similarly classified according to their space groups. After a periodic identification and a Z2 projection, the array is transformed by T-duality to a system of NS5-branes with the SU(2) structure, and a further standard embedding yields, though singular, a half-BPS heterotic 5-brane background with warped compact transverse dimensions. A discussion is given of the possibility of probing the singular geometry by two-dimensional gauge theories.

Imazato, Harunobu; Yata, Masaya
2011-01-01

454

CRYSTALLIZATION NOTE Crystallization and Preliminary X-Ray Diffraction Analysis

  Biology and Medicine Websites

Summary: cloacae have been grown by vapor diffusion using phosphate buffer as the precipitant. The crystals belong and stabilizes them to their high internal osmotic pressure. The major structural element of the wall


455

Active crystals and their stability

  Condensed Matter (arXiv)

Summary: A recently introduced active phase field crystal model describes the formation of ordered resting and traveling crystals in systems of self-propelled particles. Increasing the active drive, a resting crystal can be forced to perform collectively ordered migration as a single traveling object. We demonstrate here that these ordered migrating structures are linearly stable. In other words, during migration, the single crystalline texture together with the globally ordered collective motion is preserved even on large length scales. Furthermore, we consider self-propelled particles on a substrate that are surrounded by a thin fluid film. We find that in this case the resulting hydrodynamic interactions can destabilize the order.

Andreas M. Menzel; Takao Ohta; Hartmut Löwen
2014-01-21

456

Light propagation in biaxial crystals

  CERN Preprints

Summary: We present a formalism able to predict the transformation of light beams passing through biaxial crystals. We use this formalism to show both theoretically and experimentally the transition from double refraction to conical refraction, which is found when light propagates along one of the optic axes of a biaxial crystal. Additionally, we demonstrate that the theory is applicable both to non-cylindrically symmetric and non-homogeneously polarized beams by predicting the transformation of input beams passing through a cascade of biaxial crystals.

Turpin, Alex; Kalkandjiev, Todor K; Mompart, Jordi
2015-01-01

457

Crystals and liquid crystals confined to curved geometries

  Condensed Matter (arXiv)

Summary: This review introduces the elasticity theory of two-dimensional crystals and nematic liquid crystals on curved surfaces, the energetics of topological defects (disclinations, dislocations and pleats) in these ordered phases, and the interaction of defects with the underlying curvature. This chapter concludes with two cases of three-dimensional nematic phases confined to spaces with curved boundaries, namely a torus and a spherical shell.

Vinzenz Koning; Vincenzo Vitelli
2014-01-20

458

Beyond the Dirac phase factor: Dynamical Quantum Phase-Nonlocalities in the Schroedinger Picture

  Mathematical Physics (arXiv)

Summary: Generalized solutions of the standard gauge transformation equations are presented and discussed in physical terms. They go beyond the usual Dirac phase factors and they exhibit nonlocal quantal behavior, with the well-known Relativistic Causality of classical fields affecting directly the phases of wavefunctions in the Schroedinger Picture. These nonlocal phase behaviors, apparently overlooked in path-integral approaches, give a natural account of the dynamical nonlocality character of the various (even static) Aharonov-Bohm phenomena, while at the same time they seem to respect Causality. Indeed, for particles passing through nonvanishing magnetic or electric fields they lead to cancellations of Aharonov-Bohm phases at the observation point, generalizing earlier semiclassical experimental observations (of Werner & Brill) to delocalized (spread-out) quantum states. This leads to a correction of previously unnoticed sign-errors in the literature, and to a natural explanation of the deeper reason why certain time-dependent semiclassical arguments are consistent with static results in purely quantal Aharonov-Bohm configurations. These nonlocalities also provide a remedy for misleading results propagating in the literature (concerning an uncritical use of Dirac phase factors, that persists since the time of Feynman's work on path integrals). They are shown to conspire in such a way as to exactly cancel the instantaneous Aharonov-Bohm phase and recover Relativistic Causality in earlier "paradoxes" (such as the van Kampen thought-experiment), and to also complete Peshkin's discussion of the electric Aharonov-Bohm effect in a causal manner. The present formulation offers a direct way to address time-dependent single- vs double-slit experiments and the associated causal issues -- issues that have recently attracted attention, with respect to the inability of current theories to address them.

Konstantinos Moulopoulos
2011-05-11

459

Beyond the Dirac phase factor: Dynamical Quantum Phase-Nonlocalities in the Schrödinger Picture

  Mathematical Physics (arXiv)

Summary: Generalized solutions of the standard gauge transformation equations are presented and discussed in physical terms. They go beyond the usual Dirac phase factors and they exhibit nonlocal quantal behavior, with the well-known Relativistic Causality of classical fields affecting directly the phases of wavefunctions in the Schr\\"odinger Picture. These nonlocal phase behaviors, apparently overlooked in path-integral approaches, give a natural account of the dynamical nonlocality character of the various (even static) Aharonov-Bohm phenomena, while at the same time they seem to respect Causality. For particles passing through nonvanishing magnetic or electric fields they lead to cancellations of Aharonov-Bohm phases at the observation point, generalizing earlier semiclassical experimental observations (of Werner & Brill) to delocalized (spread-out) quantum states. This leads to a correction of previously unnoticed sign-errors in the literature, and to a natural explanation of the deeper reason why certain time-dependent semiclassical arguments are consistent with static results in purely quantal Aharonov-Bohm configurations. These nonlocalities also provide a remedy for misleading results propagating in the literature (concerning an uncritical use of Dirac phase factors, that persists since the time of Feynman's work on path integrals). They are shown to conspire in such a way as to exactly cancel the instantaneous Aharonov-Bohm phase and recover Relativistic Causality in earlier " paradoxes" (such as the van Kampen thought-experiment), and to also complete Peshkin's discussion of the electric Aharonov-Bohm effect in a causal manner. The present formulation offers a direct way to address time-dependent single- vs double-slit experiments and the associated causal issues -- issues that have recently attracted attention, with respect to the inability of current theories to address them.

Konstantinos Moulopoulos
2011-09-08

460

Circular birefringence in crystal optics

  CERN Preprints

Summary: In crystal optics the special status of the rest frame of the crystal means that space-time symmetry is less restrictive of electrodynamic phenomena than it is of static electromagnetic effects. A relativistic justification for this claim is provided and its consequences for the analysis of optical activity are explored. The discrete space-time symmetries P and T that lead to classification of static property tensors as polar or axial, time-invariant (-i) or time-change (-c) are shown to be connected by orientation considerations. The connection finds expression in the dynamic phenomenon of gyrotropy in certain, symmetry determined, crystal classes. In particular, the degeneracies of forward and backward waves in optically active crystals arise from the covariance of the wave equation under space-time (PT) reversal.

Potton, Richard J
2014-01-01

461

Radiating dipoles in photonic crystals

  Quantum Physics (arXiv)

Summary: The radiation dynamics of a dipole antenna embedded in a Photonic Crystal are modeled by an initially excited harmonic oscillator coupled to a non--Markovian bath of harmonic oscillators representing the colored electromagnetic vacuum within the crystal. Realistic coupling constants based on the natural modes of the Photonic Crystal, i.e., Bloch waves and their associated dispersion relation, are derived. For simple model systems, well-known results such as decay times and emission spectra are reproduced. This approach enables direct incorporation of realistic band structure computations into studies of radiative emission from atoms and molecules within photonic crystals. We therefore provide a predictive and interpretative tool for experiments in both the microwave and optical regimes.

Kurt Busch; Nipun Vats; Sajeev John; Barry C. Sanders
2000-06-02

462

Radiating dipoles in photonic crystals

  CERN Preprints

Summary: The radiation dynamics of a dipole antenna embedded in a Photonic Crystal are modeled by an initially excited harmonic oscillator coupled to a non--Markovian bath of harmonic oscillators representing the colored electromagnetic vacuum within the crystal. Realistic coupling constants based on the natural modes of the Photonic Crystal, i.e., Bloch waves and their associated dispersion relation, are derived. For simple model systems, well-known results such as decay times and emission spectra are reproduced. This approach enables direct incorporation of realistic band structure computations into studies of radiative emission from atoms and molecules within photonic crystals. We therefore provide a predictive and interpretative tool for experiments in both the microwave and optical regimes.

Busch, K; John, S; Sanders, B C; Busch, Kurt; Vats, Nipun; John, Sajeev; Sanders, Barry C.
2000-01-01

463

Absence of Quantum Time Crystals

  Mathematical Physics (arXiv)

Summary: In analogy with crystalline solids around us, Wilczek recently proposed the idea of "time crystals" as phases that spontaneously break the continuous time translation into a discrete subgroup. The proposal stimulated further studies and vigorous debates whether it can be realized in a physical system. However, a precise definition of the time crystal is needed to resolve the issue. Here we first present a definition of time crystals based on the time-dependent correlation functions of the order parameter. We then prove a no-go theorem that rules out the possibility of time crystals defined as such, in the ground state or in the canonical ensemble of a general Hamiltonian, which consists of not-too-long-range interactions.

Haruki Watanabe; Masaki Oshikawa
2014-12-29

464

Crystal Growth Inside an Octant

  Mathematical Physics (arXiv)

Summary: We study crystal growth inside an infinite octant on a cubic lattice. The growth proceeds through the deposition of elementary cubes into inner corners. After re-scaling by the characteristic size, the interface becomes progressively more deterministic in the long-time limit. Utilizing known results for the crystal growth inside a two-dimensional corner, we propose a hyperbolic partial differential equation for the evolution of the limiting shape. This equation is interpreted as a Hamilton-Jacobi equation which helps in finding an analytical solution. Simulations of the growth process are in excellent agreement with analytical predictions. We then study the evolution of the sub-leading correction to the volume of the crystal, the asymptotic growth of the variance of the volume of the crystal, and the total number of inner and outer corners. We also show how to generalize the results to arbitrary spatial dimension.

Jason Olejarz; P. L. Krapivsky
2013-07-19

465

Crystal Melting and Black Holes

  HEP - Theory (arXiv)

Summary: It has recently been shown that the statistical mechanics of crystal melting maps to A-model topological string amplitudes on non-compact Calabi-Yau spaces. In this note we establish a one to one correspondence between two and three dimensional crystal melting configurations and certain BPS black holes given by branes wrapping collapsed cycles on the orbifolds C^2/Z_n and C^3/Z_n x Z_n in the large n limit. The ranks of gauge groups in the associated gauged quiver quantum mechanics determine the profiles of crystal melting configurations and the process of melting maps to flop transitions which leave the background Calabi-Yau invariant. We explain the connection between these two realizations of crystal melting and speculate on the underlying physical meaning.

Jonathan J. Heckman; Cumrun Vafa
2006-10-02

466

Heat transport through ion crystals

  Quantum Physics (arXiv)

Summary: We study the thermodynamical properties of crystals of trapped ions which are laser cooled to two different temperatures in two separate regions. We show that these properties strongly depend on the structure of the ion crystal. Such structure can be changed by varying the trap parameters and undergoes a series of phase transitions from linear to zig-zag or helicoidal configurations. Thus, we show that these systems are ideal candidates to observe and control the transition from anomalous to normal heat transport. All structures behave as `heat superconductors', with a thermal conductivity increasing linearly with system size and a vanishing thermal gradient inside the system. However, zig-zag and helicoidal crystals turn out to be hyper sensitive to disorder having a linear temperature profile and a length independent conductivity. Interestingly, disordered 2D ion crystals are heat insulators. Sensitivity to disorder is much smaller in the 1D case.

Nahuel Freitas; Esteban Martinez; Juan Pablo Paz
2014-12-09

467

Active materials in photonic crystals

  MIT - DSpace

Summary: I analyze new phenomena arising from embedding active materials inside of photonic crystal structures. These structures strongly modify the photonic local density of states (LDOS), leading to quantitative and qualitative ...

Bermel, Peter (Peter A.)
2007-01-01

468

Banding in single crystals during plastic deformation

  Engineering Websites

Summary: Banding in single crystals during plastic deformation M. Arul Kumar a Sivasambu Mahesh a,b a. India. Abstract A rigid-plastic rate-independent crystal plasticity model capable of capturing band- ing such as dense dislocation walls. Key words: crystal plasticity, single crystal, macroscopic shear band, regular

Mahesh, Sivasambu

469

Crystal melting on toric surfaces

  HEP - Theory (arXiv)

Summary: We study the relationship between the statistical mechanics of crystal melting and instanton counting in N=4 supersymmetric U(1) gauge theory on toric surfaces. We argue that, in contrast to their six-dimensional cousins, the two problems are related but not identical. We develop a vertex formalism for the crystal partition function, which calculates a generating function for the dimension 0 and 1 subschemes of the toric surface, and describe the modifications required to obtain the corresponding gauge theory partition function.

Michele Cirafici; Amir-Kian Kashani-Poor; Richard J. Szabo
2009-12-18

470

Phase transitions in layered crystals

  CERN Preprints

Summary: It is demonstrated by analyzing real examples that phase transitions in layered crystals occur like all other solid-state phase transitions by nucleation and crystal growth, but have a specific morphology. There the nucleation is epitaxial, resulting in the rigorous orientation relationship between the polymorphs, such that the direction of molecular layers are preserved. The detailed molecular mechanism of these phase transitions and formation of the laminar domain structures are described and related to the nature of ferroelectrics.

Mnyukh, Yuri
2011-01-01

471

Crystal melting on toric surfaces

  CERN Preprints

Summary: We study the relationship between the statistical mechanics of crystal melting and instanton counting in N=4 supersymmetric U(1) gauge theory on toric surfaces. We argue that, in contrast to their six-dimensional cousins, the two problems are related but not identical. We develop a vertex formalism for the crystal partition function, which calculates a generating function for the dimension 0 and 1 subschemes of the toric surface, and describe the modifications required to obtain the corresponding gauge theory partition function.

Cirafici, Michele; Szabo, Richard J
2009-01-01

472

Proposal of the Crystal Experiment

  CERN Preprints

Summary: The CRYSTAL experiment intends to assess the possibility of using bent silicon crystals as primary collimators to direct the beam halo onto the secondary absorber thus reducing outscattering, beam losses in critical regions and radiation load. CRYSTAL has received full support from the LHC Technical Committee on the 30th of January. Four agencies have expressed their interest in the project: CERN, the Russian Institutions (PNPI, IHEP, JINR), INFN (Sections of Ferrara, Legnaro, Milano Bicocca, Roma1) and US LARP (BNL, FNAL, SLAC). The first version of the MoU is circulating among the collaboration and will be ready to be sent to the funding agencies before the end of April. This document briefly reviews the CRYSTAL experiment goals, its organization, the cost sharing among the agencies, the needed manpower and the time schedule. Appendix A describes what has already been done with crystals in collimation and why crystals could play a fundamental role while Appendix B analyzes in detail the items summarized in ...

Scandale, Walter
2008-01-01

473

ON THE COMBINATORICS OF CRYSTAL GRAPHS, II. THE CRYSTAL CRISTIAN LENART

  Mathematics Websites

Summary: ON THE COMBINATORICS OF CRYSTAL GRAPHS, II. THE CRYSTAL COMMUTOR CRISTIAN LENART Abstract. We present an explicit combinatorial realization of the commutor in the category of crystals which was first. 1. Introduction We work in the category g-Crystals of crystals corresponding to representations

Lenart, Cristian

474

Crystallization of Difructrose Anhydride III (DFA III) in Batch Cooling Crystallization System: The Influence of Initial

  CiteSeer

Summary: Crystallization of Difructose Anhydride III (DFA III) was investigated in batch cooling crystallization system, in which profile of temperature was controlled cooling temperature. The measured experimental parameter were crystal yield and crystal size distribution (CSD). The influence of initial supersaturation on the crystallization of DFA III is discussed herein.

Umi Laila; Sri Pudjiraharti; Wawan Kosasih

475

Toward photonic-crystal metamaterials: Creating magnetic emitters in photonic crystals

  Materials Science Websites

Summary: Toward photonic-crystal metamaterials: Creating magnetic emitters in photonic crystals M. L explore the possibility of designing photonic crystals to act as magnetic metamaterials: structures that exhibit magnetic properties despite the nonmagnetic character of their constituents. The building blocks


476

Hydrodynamics of polar liquid crystals

  Condensed Matter (arXiv)

Summary: Starting from a microscopic definition of an alignment vector proportional to the polarization, we discuss the hydrodynamics of polar liquid crystals with local $C_{\\infty v}$-symmetry. The free energy for polar liquid crystals differs from that of nematic liquid crystals ($D_{\\infty h}$) in that it contains terms violating the ${\\bf{n}}\\to -{\\bf{n}}$ symmetry. First we show that these $\\mathcal{Z}_2$-odd terms induce a general splay instability of a uniform polarized state in a range of parameters. Next we use the general Poisson-bracket formalism to derive the hydrodynamic equations of the system in the polarized state. The structure of the linear hydrodynamic modes confirms the existence of the splay instability.

William Kung; M. Cristina Marchetti; Karl Saunders
2006-03-01

477

Nonlinear hydrodynamic theory of crystallization

  Condensed Matter (arXiv)

Summary: We present an isothermal fluctuating nonlinear hydrodynamic theory of crystallization in molecular liquids. A dynamic coarse-graining technique is used to derive the velocity field, a phenomenology, which allows a direct coupling between the free energy functional of the classical Density Functional Theory and the Navier-Stokes equation. Contrary to the Ginzburg-Landau type amplitude theories, the dynamic response to elastic deformations is described by parameter-free kinetic equations. Employing our approach to the free energy functional of the Phase-Field Crystal model, we recover the classical spectrum for the phonons and the steady-state growth fronts. The capillary wave spectrum of the equilibrium crystal-liquid interface is in a good qualitative agreement with the molecular dynamics simulations.

Gyula I. Tóth; László Gránásy; György Tegze
2013-10-14

478

Matryoshka Locally Resonant Sonic Crystal

  CERN Preprints

Summary: The results of numerical modelling of sonic crystals with resonant array elements are reported. The investigated resonant elements include plain slotted cylinders as well as various their combinations, in particular, Russian doll or Matryoshka configurations. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. The general concept of a locally resonant sonic crystal is proposed, which utilises acoustic resonances to form additional band gaps that are decoupled from Bragg gaps. An existence of a separate attenuation mechanism associated with the resonant elements, which increases performance in the lower frequency regime has been identified. The results show a formation of broad band gaps positioned significantly below the first Bragg frequency. For low frequency broadband attenuation a most optimal configuration is the Matryoshka sonic crystal, where each scattering unit is composed of multiple concentric slotted cylinders. Thi...

Elford, Daniel P; Kusmartsev, Feodor V; Swallowe, Gerry M
2011-01-01

479

Growth of Equally-Sized Insulin Crystals

  CERN Preprints

Summary: Guidelines for growing insulin crystals of a uniform size are formulated and tested experimentally. A simple theoretical model based on the balance of matter predicts the time evolution of the crystal size and supersaturation. The time dependence of the size is checked experimentally. The experimental approach decouples crystal nucleation and growth processes according to the classical nucleation-growth-separation principle. Strict control over the nucleation process is exerted. Crystalline substance dispersity is predetermined during the nucleation stage of a batch crystallization process. To avert nutrition competition during the crystal growth stage, the number density of nucleated crystals is preset to be optimal.

Nanev, Christo N; Hodzhaoglu, Feyzim V
2013-01-01

480

Electronically excited cold ion crystals

  Quantum Physics (arXiv)

Summary: The laser excitation of an ion crystal to high lying and long-lived electronic states is a genuine many-body process even if in fact only a single ion is excited. This is a direct manifestation of the strong coupling between internal and external dynamics and becomes most apparent in the vicinity of a structural phase transition. Here we show that utilizing highly excited states offers a new approach to the coherent manipulation of ion crystals. This permits the study of phenomena which rely on a strong coupling between electronic and vibrational dynamics and opens up a route towards the quantum simulation of molecular processes in a Paul trap.

Weibin Li; Igor Lesanovsky
2011-08-17

481

Quantum Crystals and Spin Chains

  HEP - Theory (arXiv)

Summary: In this note, we discuss the quantum version of the melting crystal corner in one, two, and three dimensions, generalizing the treatment for the quantum dimer model. Using a mapping to spin chains we find that the two--dimensional case (growth of random partitions) is integrable and leads directly to the Hamiltonian of the Heisenberg XXZ ferromagnet. The three--dimensional case of the melting crystal corner is described in terms of a system of coupled XXZ spin chains. We give a conjecture for its mass gap and analyze the system numerically.

Robbert Dijkgraaf; Domenico Orlando; Susanne Reffert
2008-08-11

482

Acoustooptic Diffraction in Borate Crystals

  Physics (arXiv)

Summary: The efficiency of acoustooptic (AO) diffraction in a-BaB2O4 and Li2B4O7 crystals is studied experimentally. The crystals are shown to be quite good AO materials. The efficiency of AO diffraction in a-BaB2O4 reaches h=30% at the electric signal power of P=0.7W for the transverse acoustic wave and 15% at the power of P=0.56W for the longitudinal wave. The same parameter for Li2B4O7 reaches h=21% at P=0,81W for the longitudinal acoustic wave.

I. Martynyuk-Lototska; T. Dudok; O. Krupych; V. Adamiv; Ye. Smirnov; R. Vlokh
2007-08-15

483

Gravitational Annealing of Colloidal Crystals

  Condensed Matter (arXiv)

Summary: A silica colloidal crystal obtained by centrifugation at 9 G for 2 days in water was annealed by additional stronger centrifugation at 50 G for 5 days. The number of the striations observed in the colloidal crystal under crossed polarized light decreased at some parts in a growth container after additional centrifugation, while the number alse increase at the other parts. The decrease probably shows the shrinkage of the stacking disorders under high gravity, while the increase probably shows the production of new stacking disorder.

Yoshihisa Suzuki; Jin Endoh; Atsushi Mori; Tomoki Yabutani; Katsuhiro Tamura
2012-01-20

484

Quantization of the canonically conjugate pair angle and orbital angular momentum

  Mathematical Physics (arXiv)

Summary: The question how to quantize a classical system where an angle phi is one of the basic canonical variables has been controversial since the early days of quantum mechanics. The problem is that the angle is a multivalued or discontinuous variable on the corresponding phase space. The remedy is to replace phi by the smooth periodic functions cos phi and sin phi. In the case of the canonical pair (phi,l),l: orbital angular momentum (OAM), the phase space S_(phi,l) ={phi in R mod 2pi, l in R} has the global structure S^1 x R of a cylinder on which the Poisson brackets of the 3 functions cos phi, sin phi and l obey the Lie algebra of the euclidean group E(2) in the plane. This property provides the basis for the quantization of the system in terms of irreducible unitary representations of the group E(2) or of its covering groups. A crucial point is that - due to the fact that the subgroup SO(2) = S^1 is multiply connected - these representations allow for fractional OAM l = n + c, c in [0,1). Such c not 0 have already been observed in cases like the Aharonov-Bohm and the fractional quantum Hall effects and they correspond to the quasi-momenta of Bloch waves in ideal crystals. The proposal of the present paper is to look for fractional OAM in connection with the quantum optics of Laguerre-Gaussian laser modes in external magnetic fields. The quantum theory of the phase space S_(phi,l) in terms of unitary representations of E(2) allows for two types of "coherent" states the properties of which are discussed in detail: Non-holomorphic minimal uncertainty states and holomorphic ones associated with Bargmann-Segal Hilbert spaces.

H. A. Kastrup
2006-03-29

485

Space-time crystals of trapped ions

  Quantum Physics (arXiv)

Summary: Spontaneous symmetry breaking can lead to the formation of time crystals, as well as spatial crystals. Here we propose a space-time crystal of trapped ions and a method to realize it experimentally by confining ions in a ring-shaped trapping potential with a static magnetic field. The ions spontaneously form a spatial ring crystal due to Coulomb repulsion. This ion crystal can rotate persistently at the lowest quantum energy state in magnetic fields with fractional fluxes. The persistent rotation of trapped ions produces the temporal order, leading to the formation of a space-time crystal. We show that these space-time crystals are robust for direct experimental observation. We also study the effects of finite temperatures on the persistent rotation. The proposed space-time crystals of trapped ions provide a new dimension for exploring many-body physics and emerging properties of matter.

Tongcang Li; Zhe-Xuan Gong; Zhang-Qi Yin; H. T. Quan; Xiaobo Yin; Peng Zhang; L. -M. Duan; Xiang Zhang
2013-06-19

486

Measuring Light Reflectance of BGO Crystal Surfaces

  University of California eScholarship Repository

Summary: Monte Carlo methods, scintillation crystal T I. Icrystal setup with a surface finish, reflector, and coupling method,crystals for a variety of commonly used surface finishes, reflectors, and coupling methods.

Janecek, Martin
2009-01-01

487

Liquid Crystals and Nanoscale Patterned Surfaces

  Materials Science Websites

Summary: to crystal structure, after spin coating Silicon Wafer Spin coated with PS, Rubbed *** Rubbed with a Cotton *** Rubbed with a Cotton Swap, 100 times in the direction parallel to crystal structure, after spin coating

Petta, Jason

488

Photon tunnelling microscopy of polyethylene single crystals

  Materials Science Websites

Summary: Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

Srinivasarao, Mohan

489

Advances and New Directions in Crystallization Control

  Engineering Websites

Summary: processing, process control, polymorphism, microfluidics, model predictive control Abstract The academic of crystal size and polymorphic identity. Research opportunities are described in model-free controller AND BACKGROUND Crystallization from solution is ubiquitous in many industries including fine chemicals, food

Braatz, Richard D.

490

NMR IN MIXED LIQUID CRYSTALS

  CiteSeer

Summary: NMR studies in more than one and in mixed liquid crystals have led to novel applications of NMR and enhanced the scope of NMR spectroscopy of oriented systems in providing spectral, structural and conformational information which otherwise cannot be derived conveniently. The results are c r i t i c

C. L. Khetrapal

491

Continuum Theory of Polymer Crystallization

  Condensed Matter (arXiv)

Summary: We present a kinetic model of crystal growth of polymers of finite molecular weight. Experiments help to classify polymer crystallization broadly into two kinetic regimes. One is observed in melts or in high molar mass polymer solutions and is dominated by nucleation control with $G \\sim \\exp(1/T \\Delta T)$, where $G$ is the growth rate and $\\Delta T$ is the super-cooling. The other is observed in low molar mass solutions (as well as for small molecules) and is diffusion controlled with $G \\sim \\Delta T$, for small $\\Delta T$. Our model unifies these two regimes in a single formalism. The model accounts for the accumulation of polymer chains near the growth front and invokes an entropic barrier theory to recover both limits of nucleation and diffusion control. The basic theory applies to both melts and solutions, and we numerically calculate the growth details of a single crystal in a dilute solution. The effects of molecular weight and concentration are also determined considering conventional polymer dynamics. Our theory shows that entropic considerations, in addition to the traditional energetic arguments, can capture general trends of a vast range of phenomenology. Unifying ideas on crystallization from small molecules and from flexible polymer chains emerge from our theory.

Arindam Kundagrami; M. Muthukumar
2006-12-19

492

Magnonic crystals B. Hillebrands1

  Biology and Medicine Websites

Summary: ) ­ are the magnetic analog of photonic and sonic crystals. Spin-wave excitation spectra of such structures exhibit a range of interesting features including band gaps over which spin wave propagation is prohibited. MC technologically relevant functionality [1-4]. Geometrical structuring of a uniform spin-wave waveguide

Paris-Sud 11, Université de

493

Liquid Crystals in Electric Field

  Condensed Matter (arXiv)

Summary: We present a general theory of electric field effects in liquid crystals where the dielectric tensor depends on the orientation order. As applications, we examine (i) the director fluctuations in nematic states in electric field for arbitrary strength of the dielectric anisotropy and (ii) deformation of the nematic order around a charged particle. Some predictions are made for these effects.

Akira Onuki
2003-09-28

494

Phonon dispersions of cluster crystals

  Condensed Matter (arXiv)

Summary: We analyze the ground states and the elementary collective excitations (phonons) of a class of systems, which form cluster crystals in the absence of attractions. Whereas the regime of moderate-to-high-temperatures in the phase diagram has been analyzed in detail by means of density functional considerations (Likos C N, Mladek B M, Gottwald D and Kahl G 2007 {\\it J.~Chem.~Phys.}\\ {\\bf 126} 224502), the present approach focuses on the complementary regime of low temperatures. We establish the existence of an infinite cascade of isostructural transitions between crystals with different lattice site occupancy at $T=0$ and we quantitatively demonstrate that the thermodynamic instabilities are bracketed by mechanical instabilities arising from long-wavelength acoustical phonons. We further show that all optical modes are degenerate and flat, giving rise to perfect realizations of Einstein crystals. We calculate analytically the complete phonon spectrum for the whole class of models as well as the Helmholtz free energy of the systems. On the basis of the latter, we demonstrate that the aforementioned isostructural phase transitions must terminate at an infinity of critical points at low temperatures, brought about by the anharmonic contributions in the Hamiltonian and the hopping events in the crystals.

Tim Neuhaus; Christos N. Likos
2010-08-11

495

Fig. 1. (a) crystals ar

  Materials Science Websites

Summary: elength-scale a as well as their version at sing ociety of Americ 0230) Optical Dev cavities with h ations single-p el, will be discu Photonic Crystals ctors (Q) have nanophotoni Quality factor r group [1-4] ra

Loncar, Marko

496

Protein crystallization in confined geometries

  Condensed Matter (arXiv)

Summary: We studied the crystallization of a globular protein, lysozyme, in the cubic phase of the lipid monoolein. The solubility of lysozyme in salt solution decreased by a factor of $\\sim 4$ when confined in cubic phase. Calculations and Monte Carlo simulations show that this can be explained by the {\\it confinement} of lysozyme molecules to the narrow water cells in the cubic phase.

S. Tanaka; S. U. Egelhaaf; W. C. K. Poon
2003-09-16

497

On twinning in smectic crystals

  Condensed Matter (arXiv)

Summary: It is shown that mechanical twinning in smectic crystals is possible. The structure of the boundary of twins for a small disorientation of crystallites is determined. The periodic twin structure, which should appear at the tension of the smectic layer, is proposed.

V. I. Marchenko
2013-04-26

498

Precision Crystal Calorimetry in High Energy Physics

  HEP - Experiment (arXiv)

Summary: Crystal Calorimetry is widely used in high energy physics because of its precision. Recent development in crystal technology identified two key issues to reach and maintain crystal precision: light response uniformity and calibration in situ. Crystal radiation damage is understood. While the damage in alkali halides is found to be caused by the oxygen/hydroxyl contamination, it is the structure defects, such as oxygen vacancies, cause damage in oxides.

Ren-yuan Zhu
1999-03-14

499

Journal of Crystal Growth 122 (1992) 286--292 j o, CRYSTAL North-Holland GROWTH

  Biology and Medicine Websites

Summary: Journal of Crystal Growth 122 (1992) 286--292 j o, CRYSTAL North-Holland GROWTH Derivatization-dimensional crystals of ribosomal particles Source Growth from °~ Cell dimensions (A) Resolution b) (A) 70S Thermus attached to whole ribosomes and to their small and large subunits prior to their crystallization. X

Yonath, Ada E.
1992-01-01

500

ELSEVIER Journal of Crystal Growth 171 (1997) 442-446 j........ CRYSTAL

  Physics Websites

Summary: ELSEVIER Journal of Crystal Growth 171 (1997) 442-446 j........ CRYSTAL G R O W T H Epitaxial polycrystalline structures were established on Si(111) substrates. The excellent crystal growth of the permalloy The crystal growth of permalloy films was carried out by vacuum product molecular beam epitaxy (MBE-930

Huang, Jung-Chun
1997-01-01

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