Developing and Researching PhET simulations for Teaching Quantum Mechanics S. B. McKagan,1
Colorado at Boulder, University of
(PhET) Project, known for its interactive computer simulations for teaching and learning physics, now includes 18 simulations on quantum mechanics designed to improve learning of this difficult subject. OurDeveloping and Researching PhET simulations for Teaching Quantum Mechanics S. B. McKagan,1 K. K
Quantum mechanical Carnot engine
Bender, C M; Meister, B K
2000-01-01T23:59:59.000Z
A cyclic thermodynamic heat engine runs most efficiently if it is reversible. Carnot constructed such a reversible heat engine by combining adiabatic and isothermal processes for a system containing an ideal gas. Here, we present an example of a cyclic engine based on a single quantum-mechanical particle confined to a potential well. The efficiency of this engine is shown to equal the Carnot efficiency because quantum dynamics is reversible. The quantum heat engine has a cycle consisting of adiabatic and isothermal quantum processes that are close analogues of the corresponding classical processes.
Quantum mechanical Carnot engine
C. M. Bender; D. C. Brody; B. K. Meister
2000-07-03T23:59:59.000Z
A cyclic thermodynamic heat engine runs most efficiently if it is reversible. Carnot constructed such a reversible heat engine by combining adiabatic and isothermal processes for a system containing an ideal gas. Here, we present an example of a cyclic engine based on a single quantum-mechanical particle confined to a potential well. The efficiency of this engine is shown to equal the Carnot efficiency because quantum dynamics is reversible. The quantum heat engine has a cycle consisting of adiabatic and isothermal quantum processes that are close analogues of the corresponding classical processes.
Quantum Leap Quantum Mechanics' Killer App
Bigelow, Stephen
Quantum Leap Quantum Mechanics' Killer App Q&A with Craig Hawker Director of the Materials Research. Q&A with Craig Hawker LEAP The Materials Research Laboratory is the only Wes
Nonlinear friction in quantum mechanics
Roumen Tsekov
2013-03-10T23:59:59.000Z
The effect of nonlinear friction forces in quantum mechanics is studied via dissipative Madelung hydrodynamics. A new thermo-quantum diffusion equation is derived, which is solved for the particular case of quantum Brownian motion with a cubic friction. It is extended also by a chemical reaction term to describe quantum reaction-diffusion systems with nonlinear friction as well.
Time Gravity and Quantum Mechanics
W. G. Unruh
1993-12-17T23:59:59.000Z
Time plays different roles in quantum mechanics and gravity. These roles are examined and the problems that the conflict in the roles presents for quantum gravity are briefly summarised.
From Quantum Mechanics to Thermodynamics?
Steinhoff, Heinz-Jürgen
From Quantum Mechanics to Thermodynamics? Dresden, 22.11.2004 Jochen Gemmer Universit¨at Osnabr to thermodynamical behavior · Quantum approach to thermodynamical behavior · The route to equilibrium · Summary of thermodynamical behavior entirely on the basis of Hamilton models and Schr¨odinger-type quantum dynamics. · define
Quantum Mechanical Clock and Classical Relativistic Clock
Hitoshi Kitada
2004-07-08T23:59:59.000Z
A cyclic nature of quantum mechanical clock is discussed as ``quantization of time." Quantum mechanical clock is seen to be equivalent to the relativistic classical clock.
Phase space quantum mechanics - Direct
Nasiri, S.; Sobouti, Y.; Taati, F. [Institute for Advanced Studies in Basic Sciences, Zanjan, 45195-1159 (Iran, Islamic Republic of) and Department of Physics, Zanjan University, Zanjan (Iran); Institute for Advanced Studies in Basic Sciences, Zanjan, 45195-1159 (Iran, Islamic Republic of); Institute for Advanced Studies in Basic Sciences, Zanjan, 45195-1159 (Iran, Islamic Republic of) and Department of Physics, University of Kurdistan, D-78457 Sanadaj (Iran)
2006-09-15T23:59:59.000Z
Conventional approach to quantum mechanics in phase space (q,p), is to take the operator based quantum mechanics of Schroedinger, or an equivalent, and assign a c-number function in phase space to it. We propose to begin with a higher level of abstraction, in which the independence and the symmetric role of q and p is maintained throughout, and at once arrive at phase space state functions. Upon reduction to the q- or p-space the proposed formalism gives the conventional quantum mechanics, however, with a definite rule for ordering of factors of noncommuting observables. Further conceptual and practical merits of the formalism are demonstrated throughout the text.
Combined Quantum Mechanical and Molecular Mechanics Studies of...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Mechanical and Molecular Mechanics Studies of the Electron-Transfer Reactions Involving Carbon Tetrachloride in Combined Quantum Mechanical and Molecular Mechanics Studies of the...
Quantum Mechanics of Neutrino Oscillations
C. Giunti; C. W. Kim
2000-11-06T23:59:59.000Z
We present a simple but general treatment of neutrino oscillations in the framework of quantum mechanics using plane waves and intuitive wave packet principles when necessary. We attempt to clarify some confusing statements that have recently appeared in the literature.
Quantum McKay correspondence for disc invariants of toric Calabi-Yau 3-orbifolds
Hua-Zhong Ke; Jian Zhou
2014-10-16T23:59:59.000Z
We announce a result on quantum McKay correspondence for disc invariants of outer legs in toric Calabi-Yau 3-orbifolds, and illustrate our method in a special example $[\\mathbb C^3 /\\mathbb Z_5 (1, 1, 3)]$.
Kowalevski top in quantum mechanics
Matsuyama, A., E-mail: spamatu@ipc.shizuoka.ac.jp
2013-09-15T23:59:59.000Z
The quantum mechanical Kowalevski top is studied by the direct diagonalization of the Hamiltonian. The spectra show different behaviors depending on the region divided by the bifurcation sets of the classical invariant tori. Some of these spectra are nearly degenerate due to the multiplicity of the invariant tori. The Kowalevski top has several symmetries and symmetry quantum numbers can be assigned to the eigenstates. We have also carried out the semiclassical quantization of the Kowalevski top by the EBK formulation. It is found that the semiclassical spectra are close to the exact values, thus the eigenstates can be also labeled by the integer quantum numbers. The symmetries of the system are shown to have close relations with the semiclassical quantum numbers and the near-degeneracy of the spectra. -- Highlights: •Quantum spectra of the Kowalevski top are calculated. •Semiclassical quantization is carried out by the EBK formulation. •Quantum states are labeled by the semiclassical integer quantum numbers. •Multiplicity of the classical torus makes the spectra nearly degenerate. •Symmetries, quantum numbers and near-degenerate spectra are closely related.
The quantum field theory interpretation of quantum mechanics
Alberto C. de la Torre
2015-03-02T23:59:59.000Z
It is shown that adopting the \\emph{Quantum Field} ---extended entity in space-time build by dynamic appearance propagation and annihilation of virtual particles--- as the primary ontology the astonishing features of quantum mechanics can be rendered intuitive. This interpretation of quantum mechanics follows from the formalism of the most successful theory in physics: quantum field theory.
"Einstein's Dream" - Quantum Mechanics as Theory of Classical Random Fields
Andrei Khrennikov
2012-04-22T23:59:59.000Z
This is an introductory chapter of the book in progress on quantum foundations and incompleteness of quantum mechanics. Quantum mechanics is represented as statistical mechanics of classical fields.
Probable Inference and Quantum Mechanics
Grandy, W. T. Jr. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82070 (United States)
2009-12-08T23:59:59.000Z
In its current very successful interpretation the quantum theory is fundamentally statistical in nature. Although commonly viewed as a probability amplitude whose (complex) square is a probability, the wavefunction or state vector continues to defy consensus as to its exact meaning, primarily because it is not a physical observable. Rather than approach this problem directly, it is suggested that it is first necessary to clarify the precise role of probability theory in quantum mechanics, either as applied to, or as an intrinsic part of the quantum theory. When all is said and done the unsurprising conclusion is that quantum mechanics does not constitute a logic and probability unto itself, but adheres to the long-established rules of classical probability theory while providing a means within itself for calculating the relevant probabilities. In addition, the wavefunction is seen to be a description of the quantum state assigned by an observer based on definite information, such that the same state must be assigned by any other observer based on the same information, in much the same way that probabilities are assigned.
Quantum mechanical time contradicts the uncertainty principle
Hitoshi Kitada
1999-11-17T23:59:59.000Z
The a priori time in conventional quantum mechanics is shown to contradict the uncertainty principle. A possible solution is given.
Quantum Mechanics and Representation Theory Columbia University
Woit, Peter
Quantum Mechanics and Representation Theory Peter Woit Columbia University Texas Tech, November 21 2013 Peter Woit (Columbia University) Quantum Mechanics and Representation Theory November 2013 1 / 30, 1967 Peter Woit (Columbia University) Quantum Mechanics and Representation Theory November 2013 2 / 30
Visualizing quantum mechanics in phase space
Heiko Bauke; Noya Ruth Itzhak
2011-01-11T23:59:59.000Z
We examine the visualization of quantum mechanics in phase space by means of the Wigner function and the Wigner function flow as a complementary approach to illustrating quantum mechanics in configuration space by wave functions. The Wigner function formalism resembles the mathematical language of classical mechanics of non-interacting particles. Thus, it allows a more direct comparison between classical and quantum dynamical features.
Statistical Mechanics and Quantum Cosmology
B. L. Hu
1995-11-29T23:59:59.000Z
Statistical mechanical concepts and processes such as decoherence, correlation, and dissipation can prove to be of basic importance to understanding some fundamental issues of quantum cosmology and theoretical physics such as the choice of initial states, quantum to classical transition and the emergence of time. Here we summarize our effort in 1) constructing a unified theoretical framework using techniques in interacting quantum field theory such as influence functional and coarse-grained effective action to discuss the interplay of noise, fluctuation, dissipation and decoherence; and 2) illustrating how these concepts when applied to quantum cosmology can alter the conventional views on some basic issues. Two questions we address are 1) the validity of minisuperspace truncation, which is usually assumed without proof in most discussions, and 2) the relevance of specific initial conditions, which is the prevailing view of the past decade. We also mention how some current ideas in chaotic dynamics, dissipative collective dynamics and complexity can alter our view of the quantum nature of the universe.
Quantum mechanical effects from deformation theory
Much, A. [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig, Germany and Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)] [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig, Germany and Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)
2014-02-15T23:59:59.000Z
We consider deformations of quantum mechanical operators by using the novel construction tool of warped convolutions. The deformation enables us to obtain several quantum mechanical effects where electromagnetic and gravitomagnetic fields play a role. Furthermore, a quantum plane can be defined by using the deformation techniques. This in turn gives an experimentally verifiable effect.
Quantum ballistic evolution in quantum mechanics: Application to quantum computers
Benioff, P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
1996-08-01T23:59:59.000Z
Quantum computers are important examples of processes whose evolution can be described in terms of iterations of single-step operators or their adjoints. Based on this, Hamiltonian evolution of processes with associated step operators {ital T} is investigated here. The main limitation of this paper is to processes which evolve quantum ballistically, i.e., motion restricted to a collection of nonintersecting or distinct paths on an arbitrary basis. The main goal of this paper is proof of a theorem which gives necessary and sufficient conditions that {ital T} must satisfy so that there exists a Hamiltonian description of quantum ballistic evolution for the process, namely, that {ital T} is a partial isometry and is orthogonality preserving and stable on some basis. Simple examples of quantum ballistic evolution for quantum Turing machines with one and with more than one type of elementary step are discussed. It is seen that for nondeterministic machines the basis set can be quite complex with much entanglement present. It is also proven that, given a step operator {ital T} for an arbitrary {ital deterministic} quantum Turing machine, it is decidable if {ital T} is stable and orthogonality preserving, and if quantum ballistic evolution is possible. The proof fails if {ital T} is a step operator for a {ital nondeterministic} machine. It is an open question if such a decision procedure exists for nondeterministic machines. This problem does not occur in classical mechanics. Also the definition of quantum Turing machines used here is compared with that used by other authors. {copyright} {ital 1996 The American Physical Society.}
Treating Time Travel Quantum Mechanically
John-Mark A. Allen
2014-10-10T23:59:59.000Z
The fact that closed timelike curves (CTCs) are permitted by general relativity raises the question as to how quantum systems behave when time travel to the past occurs. Research into answering this question by utilising the quantum circuit formalism has given rise to two theories: Deutschian-CTCs (D-CTCs) and "postselected" CTCs (P-CTCs). In this paper the quantum circuit approach is thoroughly reviewed, and the strengths and shortcomings of D-CTCs and P-CTCs are presented in view of their non-linearity and time travel paradoxes. In particular, the "equivalent circuit model"---which aims to make equivalent predictions to D-CTCs, while avoiding some of the difficulties of the original theory---is shown to contain errors. The discussion of D-CTCs and P-CTCs is used to motivate an analysis of the features one might require of a theory of quantum time travel, following which two overlapping classes of new theories are identified. One such theory, the theory of "transition probability" CTCs (T-CTCs), is fully developed. The theory of T-CTCs is shown not to have certain undesirable features---such as time travel paradoxes, the ability to distinguish non-orthogonal states with certainty, and the ability to clone or delete arbitrary pure states---that are present with D-CTCs and P-CTCs. The problems with non-linear extensions to quantum mechanics are discussed in relation to the interpretation of these theories, and the physical motivations of all three theories are discussed and compared.
Quantum Statistical Mechanics. III. Equilibrium Probability
Phil Attard
2014-04-10T23:59:59.000Z
Given are a first principles derivation and formulation of the probabilistic concepts that underly equilibrium quantum statistical mechanics. The transition to non-equilibrium probability is traversed briefly.
A Process Model of Quantum Mechanics
William Sulis
2014-04-21T23:59:59.000Z
A process model of quantum mechanics utilizes a combinatorial game to generate a discrete and finite causal space upon which can be defined a self-consistent quantum mechanics. An emergent space-time M and continuous wave function arise through a non-uniform interpolation process. Standard non-relativistic quantum mechanics emerges under the limit of infinite information (the causal space grows to infinity) and infinitesimal scale (the separation between points goes to zero). The model has the potential to address several paradoxes in quantum mechanics while remaining computationally powerful.
The equivalence principle in classical mechanics and quantum mechanics
Philip D. Mannheim
2000-04-03T23:59:59.000Z
We discuss our understanding of the equivalence principle in both classical mechanics and quantum mechanics. We show that not only does the equivalence principle hold for the trajectories of quantum particles in a background gravitational field, but also that it is only because of this that the equivalence principle is even to be expected to hold for classical particles at all.
Thermodynamic integration from classical to quantum mechanics
Habershon, Scott [Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Manolopoulos, David E. [Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)
2011-12-14T23:59:59.000Z
We present a new method for calculating quantum mechanical corrections to classical free energies, based on thermodynamic integration from classical to quantum mechanics. In contrast to previous methods, our method is numerically stable even in the presence of strong quantum delocalization. We first illustrate the method and its relationship to a well-established method with an analysis of a one-dimensional harmonic oscillator. We then show that our method can be used to calculate the quantum mechanical contributions to the free energies of ice and water for a flexible water model, a problem for which the established method is unstable.
Superconformal quantum mechanics and the exterior algebra
Andrew Singleton
2014-09-11T23:59:59.000Z
We extend the differential form representation of N = (n,n) supersymmetric quantum mechanics to the superconformal case. We identify the superalgebras occurring for n = 1,2,4, give necessary and sufficient conditions for their existence, and give explicit geometric constructions of their generators and commutation relations. Quantum mechanics on the moduli space of instantons is considered as an example.
NONEQUILIBRIUM QUANTUM STATISTICAL MECHANICS AND THERMODYNAMICS #
NONEQUILIBRIUM QUANTUM STATISTICAL MECHANICS AND THERMODYNAMICS # Walid K. Abou Salem + Institut f recent progress in deriving the fundamental laws of thermodynamics (0 th , 1 st and 2 nd Âlaw) from nonequilibrium quantum statistical mechanics. Basic thermodynamic notions are clarified and di#erent reversible
Polymer Quantum Mechanics and its Continuum Limit
Alejandro Corichi; Tatjana Vukasinac; Jose A. Zapata
2007-08-22T23:59:59.000Z
A rather non-standard quantum representation of the canonical commutation relations of quantum mechanics systems, known as the polymer representation has gained some attention in recent years, due to its possible relation with Planck scale physics. In particular, this approach has been followed in a symmetric sector of loop quantum gravity known as loop quantum cosmology. Here we explore different aspects of the relation between the ordinary Schroedinger theory and the polymer description. The paper has two parts. In the first one, we derive the polymer quantum mechanics starting from the ordinary Schroedinger theory and show that the polymer description arises as an appropriate limit. In the second part we consider the continuum limit of this theory, namely, the reverse process in which one starts from the discrete theory and tries to recover back the ordinary Schroedinger quantum mechanics. We consider several examples of interest, including the harmonic oscillator, the free particle and a simple cosmological model.
Strange Bedfellows: Quantum Mechanics and Data Mining
Marvin Weinstein
2009-11-03T23:59:59.000Z
Last year, in 2008, I gave a talk titled {\\it Quantum Calisthenics}. This year I am going to tell you about how the work I described then has spun off into a most unlikely direction. What I am going to talk about is how one maps the problem of finding clusters in a given data set into a problem in quantum mechanics. I will then use the tricks I described to let quantum evolution lets the clusters come together on their own.
Testing foundations of quantum mechanics with photons
Peter Shadbolt; Jonathan C. F. Matthews; Anthony Laing; Jeremy L. O'Brien
2015-01-15T23:59:59.000Z
The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.
The Möbius Symmetry of Quantum Mechanics
Alon E. Faraggi; Marco Matone
2015-02-16T23:59:59.000Z
The equivalence postulate approach to quantum mechanics aims to formulate quantum mechanics from a fundamental geometrical principle. Underlying the formulation there exists a basic cocycle condition which is invariant under $D$--dimensional M\\"obius transformations with respect to the Euclidean or Minkowski metrics. The invariance under global M\\"obius transformations implies that spatial space is compact. Furthermore, it implies energy quantisation and undefinability of quantum trajectories without assuming any prior interpretation of the wave function. The approach may be viewed as conventional quantum mechanics with the caveat that spatial space is compact, as dictated by the M\\"obius symmetry, with the classical limit corresponding to the decompactification limit. Correspondingly, there exists a finite length scale in the formalism and consequently an intrinsic regularisation scheme. Evidence for the compactness of space may exist in the cosmic microwave background radiation.
Mossbauer neutrinos in quantum mechanics and quantum field theory
Kopp, Joachim
2009-01-01T23:59:59.000Z
We demonstrate the correspondence between quantum mechanical and quantum field theoretical descriptions of Mossbauer neutrino oscillations. First, we compute the combined rate $\\Gamma$ of Mossbauer neutrino emission, propagation, and detection in quantum field theory, treating the neutrino as an internal line of a tree level Feynman diagram. We include explicitly the effect of homogeneous line broadening due to fluctuating electromagnetic fields in the source and detector crystals and show that the resulting formula for $\\Gamma$ is identical to the one obtained previously (Akhmedov et al., arXiv:0802.2513) for the case of inhomogeneous line broadening. We then proceed to a quantum mechanical treatment of Mossbauer neutrinos and show that the oscillation, coherence and resonance terms from the field theoretical result can be reproduced if the neutrino is described as a superposition of Lorentz-shaped wave packet with appropriately chosen energies and widths. On the other hand, the emission rate and the detecti...
Noncommutative Quantum Mechanics from Noncommutative Quantum Field Theory
Pei-Ming Ho; Hsien-Chung Kao
2001-10-26T23:59:59.000Z
We derive noncommutative multi-particle quantum mechanics from noncommutative quantum field theory in the nonrelativistic limit. Paricles of opposite charges are found to have opposite noncommutativity. As a result, there is no noncommutative correction to the hydrogen atom spectrum at the tree level. We also comment on the obstacles to take noncommutative phenomenology seriously, and propose a way to construct noncommutative SU(5) grand unified theory.
Quantum Mechanical Pressure Frank Rioux
Rioux, Frank
by the kinetic theory of gases for an individual gas molecule. #12; Planck's constant. Using de Broglie's equation in the classical expression for kinetic energy converts provides, as we see now, a quantum interpretation for gas pressure. #12;To show this we will consider
Standard Quantum Limit for Probing Mechanical Energy Quantization
Corbitt, Thomas R.
We derive a standard quantum limit for probing mechanical energy quantization in a class of systems with mechanical modes parametrically coupled to external degrees of freedom. To resolve a single mechanical quantum, it ...
Nonlinear Quantum Mechanics at the Planck Scale
George Svetlichny
2004-10-27T23:59:59.000Z
I argue that the linearity of quantum mechanics is an emergent feature at the Planck scale, along with the manifold structure of space-time. In this regime the usual causality violation objections to nonlinearity do not apply, and nonlinear effects can be of comparable magnitude to the linear ones and still be highly suppressed at low energies. This can offer alternative approaches to quantum gravity and to the evolution of the early universe.
Mossbauer neutrinos in quantum mechanics and quantum field theory
Joachim Kopp
2009-06-12T23:59:59.000Z
We demonstrate the correspondence between quantum mechanical and quantum field theoretical descriptions of Mossbauer neutrino oscillations. First, we compute the combined rate $\\Gamma$ of Mossbauer neutrino emission, propagation, and detection in quantum field theory, treating the neutrino as an internal line of a tree level Feynman diagram. We include explicitly the effect of homogeneous line broadening due to fluctuating electromagnetic fields in the source and detector crystals and show that the resulting formula for $\\Gamma$ is identical to the one obtained previously (Akhmedov et al., arXiv:0802.2513) for the case of inhomogeneous line broadening. We then proceed to a quantum mechanical treatment of Mossbauer neutrinos and show that the oscillation, coherence, and resonance terms from the field theoretical result can be reproduced if the neutrino is described as a superposition of Lorentz-shaped wave packet with appropriately chosen energies and widths. On the other hand, the emission rate and the detection cross section, including localization and Lamb-Mossbauer terms, cannot be predicted in quantum mechanics and have to be put in by hand.
Spin Glass: A Bridge between quantum computation and statistical mechanics
Masayuki Ohzeki
2012-04-24T23:59:59.000Z
We show two fascinating topics lying between quantum information processing and statistical mechanics. First, we introduce an elaborated technique, the surface code, to prepare the particular quantum state with robustness against decoherence. Second, we show another interesting technique to employ quantum nature, quantum annealing. Through both of the topics, we would shed light on the birth of the interdisciplinary field between quantum mechanics and statistical mechanics.
A Signal Processing Model of Quantum Mechanics
Chris Thron; Johnny Watts
2012-05-08T23:59:59.000Z
This paper develops a deterministic model of quantum mechanics as an accumulation-and-threshold process. The model arises from an analogy with signal processing in wireless communications. Complex wavefunctions are interpreted as expressing the amplitude and phase information of a modulated carrier wave. Particle transmission events are modeled as the outcome of a process of signal accumulation that occurs in an extra (non-spacetime) dimension. Besides giving a natural interpretation of the wavefunction and the Born rule, the model accommodates the collapse of the wave packet and other quantum paradoxes such as EPR and the Ahanorov-Bohm effect. The model also gives a new perspective on the 'relational' nature of quantum mechanics: that is, whether the wave function of a physical system is "real" or simply reflects the observer's partial knowledge of the system. We simulate the model for a 2-slit experiment, and indicate possible deviations of the model's predictions from conventional quantum mechanics. We also indicate how the theory may be extended to a field theory.
Quantum Mechanical Coherence, Resonance, and Mind
Henry P. Stapp
1995-04-04T23:59:59.000Z
Norbert Wiener and J.B.S. Haldane suggested during the early thirties that the profound changes in our conception of matter entailed by quantum theory opens the way for our thoughts, and other experiential or mind-like qualities, to play a role in nature that is causally interactive and effective, rather than purely epiphenomenal, as required by classical mechanics. The mathematical basis of this suggestion is described here, and it is then shown how, by giving mind this efficacious role in natural process, the classical character of our perceptions of the quantum universe can be seen to be a consequence of evolutionary pressures for the survival of the species.
Deformation Quantization: From Quantum Mechanics to Quantum Field Theory
P. Tillman
2006-10-31T23:59:59.000Z
The aim of this paper is to give a basic overview of Deformation Quantization (DQ) to physicists. A summary is given here of some of the key developments over the past thirty years in the context of physics, from quantum mechanics to quantum field theory. Also, we discuss some of the conceptual advantages of DQ and how DQ may be related to algebraic quantum field theory. Additionally, our previous results are summarized which includes the construction of the Fedosov star-product on dS/AdS. One of the goals of these results was to verify that DQ gave the same results as previous analyses of these spaces. Another was to verify that the formal series used in the conventional treatment converged by obtaining exact and nonperturbative results for these spaces.
A New Approach to The Quantum Mechanics
Yulei Feng
2013-02-15T23:59:59.000Z
In this paper, we try to give a new approach to the quantum mechanics(QM) on the framework of quantum field theory(QFT). Firstly, we make a detail study on the (non-relativistic) Schr\\"odinger field theory, obtaining the Schr\\"odinger equation as a field equation, after field quantization, the Heisenberg equations for the momentum and position operators of the particles excited from the (Schr\\"odinger) field and the Feynman path integral formula of QM are also obtained. We then give the probability concepts of quantum mechanics in terms of a statistical ensemble, realizing the ensemble(or statistical) interpretation. With these, we make a series of conceptual modifications to the standard quantum mechanics, especially propose a new assumption about the quantum measurement theory which can solve the EPR paradox from the view of the QFT. Besides, a field theoretical description to the double-slit interference experiment is developed, obtaining the required particle number distribution. In the end, we extend all the above concepts to the relativistic case so that the ensemble interpretation is still proper. Two extra topics are added, in the first one, an operable experiment is proposed to distinguish the Copenhagen interpretation from the ensemble one via very different experimental results. While the second topic concerns with the extensions of the concept of coherent state to both the Bosonic and Fermionic field cases, to obtain the corresponding classical fields. And in the concluding section, we make some general comparisons between the standard QM and the one derived from the QFT, from which we claim that the QFT is the fundamental theory.
Does Quantum Mechanics Save Free Will?
Laszlo E. Szabo
1995-06-28T23:59:59.000Z
According to the widely accepted opinion, classical (statistical) physics does not support objective indeterminism, since the statistical laws of classical physics allow a deterministic hidden background, while --- as Arthur Fine writes polemizing with Gr\\"unbaum --- "{\\sl the antilibertarian position finds little room to breathe in a statistical world if we take laws of the quantum theory as exemplars of the statistical laws in such a world. So, it appears that, contrary to what Gr\\"unbaum claims, the libertarians' 'could have done otherwise' does indeed find support from indeterminism if we take the indeterministic laws to be of the sort found in the quantum theory.}" In this paper I will show that, quite the contrary, quantum mechanics does not save free will. For instance, the EPR experiments are compatible with a deterministic world. They admit a deterministic local hidden parameter description if the deterministic model is 'allowed' to describe not only the measurement outcomes, but also the outcomes of the 'decisions' whether this or that measurement will be performed. So, the derivation of the freedom of the will from quantum mechanics is a tautology: from the assumption that the world is indeterministic it is derived that the world cannot be deterministic.
Quantum Mechanics, Gravity, and the Multiverse
Yasunori Nomura
2012-07-30T23:59:59.000Z
The discovery of accelerating expansion of the universe has led us to take the dramatic view that our universe may be one of the many universes in which low energy physical laws take different forms: the multiverse. I explain why/how this view is supported both observationally and theoretically, especially by string theory and eternal inflation. I then describe how quantum mechanics plays a crucial role in understanding the multiverse, even at the largest distance scales. The resulting picture leads to a revolutionary change of our view of spacetime and gravity, and completely unifies the paradigm of the eternally inflating multiverse with the many worlds interpretation of quantum mechanics. The picture also provides a solution to a long-standing problem in eternal inflation, called the measure problem, which I briefly describe.
Unstable trajectories and the quantum mechanical uncertainty
Moser, Hans R. [Physics Institute, University of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland)], E-mail: moser@physik.uzh.ch
2008-08-15T23:59:59.000Z
There is still an ongoing discussion about various seemingly contradictory aspects of classical particle motion and its quantum mechanical counterpart. One of the best accepted viewpoints that intend to bridge the gap is the so-called Copenhagen Interpretation. A major issue there is to regard wave functions as probability amplitudes (usually for the position of a particle). However, the literature also reports on approaches that claim a trajectory for any quantum mechanical particle, Bohmian mechanics probably being the most prominent one among these ideas. We introduce a way to calculate trajectories as well, but our crucial ingredient is their well controlled local (thus also momentaneous) degree of instability. By construction, at every moment their unpredictability, i.e., their local separation rates of neighboring trajectories, is governed by the local value of the given modulus square of a wave function. We present extensive numerical simulations of the H and He atom, and for some velocity-related quantities, namely angular momentum and total energy, we inspect their agreement with the values appearing in wave mechanics. Further, we interpret the archetypal double slit interference experiment in the spirit of our findings. We also discuss many-particle problems far beyond He, which guides us to a variety of possible applications.
Quantum mechanics with coordinate dependent noncommutativity
Kupriyanov, V. G. [CMCC, Universidade Federal do ABC, Santo André, SP (Brazil)] [CMCC, Universidade Federal do ABC, Santo André, SP (Brazil)
2013-11-15T23:59:59.000Z
Noncommutative quantum mechanics can be considered as a first step in the construction of quantum field theory on noncommutative spaces of generic form, when the commutator between coordinates is a function of these coordinates. In this paper we discuss the mathematical framework of such a theory. The noncommutativity is treated as an external antisymmetric field satisfying the Jacobi identity. First, we propose a symplectic realization of a given Poisson manifold and construct the Darboux coordinates on the obtained symplectic manifold. Then we define the star product on a Poisson manifold and obtain the expression for the trace functional. The above ingredients are used to formulate a nonrelativistic quantum mechanics on noncommutative spaces of general form. All considered constructions are obtained as a formal series in the parameter of noncommutativity. In particular, the complete algebra of commutation relations between coordinates and conjugated momenta is a deformation of the standard Heisenberg algebra. As examples we consider a free particle and an isotropic harmonic oscillator on the rotational invariant noncommutative space.
Quantum mechanism helps agents combat "bad" social choice rules
Haoyang Wu
2011-04-22T23:59:59.000Z
Quantum strategies have been successfully applied to game theory for years. However, as a reverse problem of game theory, the theory of mechanism design is ignored by physicists. In this paper, the theory of mechanism design is generalized to a quantum domain. The main result is that by virtue of a quantum mechanism, agents who satisfy a certain condition can combat "bad" social choice rules instead of being restricted by the traditional mechanism design theory.
Quantum Mechanics of a Rotating Billiard
Nandan Jha; Sudhir R. Jain
2014-06-12T23:59:59.000Z
Integrability of a square billiard is spontaneously broken as it rotates about one of its corners. The system becomes quasi-integrable where the invariant tori are broken with respect to a certain parameter, $\\lambda = 2E/\\omega^{2}$ where E is the energy of the particle inside the billiard and $\\omega$ is the angular frequency of rotation of billiard. We study the system classically and quantum mechanically in view of obtaining a correspondence in the two descriptions. Classical phase space in Poincar\\'{e} surface of section shows transition from regular to chaotic motion as the parameter $\\lambda$ is decreased. In the Quantum counterpart, the spectral statistics shows a transition from Poisson to Wigner distribution as the system turns chaotic with decrease in $\\lambda$. The wavefunction statistics however show breakdown of time-reversal symmetry as $\\lambda$ decreases.
5.74 Introductory Quantum Mechanics II, Spring 2007
Tokmakoff, Andrei
Time-dependent quantum mechanics and spectroscopy. Topics covered include perturbation theory, two-level systems, light-matter interactions, relaxation in quantum systems, correlation functions and linear response theory, ...
5.74 Introductory Quantum Mechanics II, Spring 2003
Tokmakoff, Andrei
Time-dependent quantum mechanics and spectroscopy. Topics covered include perturbation theory, two-level systems, light-matter interactions, relaxation in quantum systems, correlation functions and linear response theory, ...
The Multiverse Interpretation of Quantum Mechanics
Raphael Bousso; Leonard Susskind
2011-07-22T23:59:59.000Z
We argue that the many-worlds of quantum mechanics and the many worlds of the multiverse are the same thing, and that the multiverse is necessary to give exact operational meaning to probabilistic predictions from quantum mechanics. Decoherence - the modern version of wave-function collapse - is subjective in that it depends on the choice of a set of unmonitored degrees of freedom, the "environment". In fact decoherence is absent in the complete description of any region larger than the future light-cone of a measurement event. However, if one restricts to the causal diamond - the largest region that can be causally probed - then the boundary of the diamond acts as a one-way membrane and thus provides a preferred choice of environment. We argue that the global multiverse is a representation of the many-worlds (all possible decoherent causal diamond histories) in a single geometry. We propose that it must be possible in principle to verify quantum-mechanical predictions exactly. This requires not only the existence of exact observables but two additional postulates: a single observer within the universe can access infinitely many identical experiments; and the outcome of each experiment must be completely definite. In causal diamonds with finite surface area, holographic entropy bounds imply that no exact observables exist, and both postulates fail: experiments cannot be repeated infinitely many times; and decoherence is not completely irreversible, so outcomes are not definite. We argue that our postulates can be satisfied in "hats" (supersymmetric multiverse regions with vanishing cosmological constant). We propose a complementarity principle that relates the approximate observables associated with finite causal diamonds to exact observables in the hat.
Clocks And Dynamics In Quantum Mechanics
Michael York
2014-07-11T23:59:59.000Z
We argue that (1) our perception of time through change and (2) the gap between reality and our observation of it are at the heart of both quantum mechanics and the dynamical mechanism of physical systems. We suggest that the origin of quantum uncertainty lies with the absence of infinities or infinitesimals in observational data and that our concept of time derives from observing changing data (events). We argue that the fundamentally important content of the Superposition Principle is not the "probability amplitude" of posterior state observation but future state availability conditional only on prior information. Since event detection also implies posterior conditions (e.g. a specific type of detectable event occurred) as well as prior conditions, the probabilities of detected outcomes are also conditional on properties of the posterior properties of the observation. Such posterior conditions cannot affect the prior state availabilities and this implies violation of counter-factual definiteness. A component of a quantum system may be chosen to represent a clock and changes in other components can then be expected to be correlated with clocks with which they are entangled. Instead of traditional time-dependent equations of motion we provide a specific mechanism whereby evolution of data is instead quasi-causally related to the relative \\availability\\ of states and equations of motion are expressed in terms of quantized clock variables. We also suggest that time-reversal symmetry-breaking in weak interactions is an artifice of a conventional choice of co-ordinate time-function. Analysis of a "free" particle suggests that conventional co-ordinate space-time emerges from how we measure the separation of objects and events.
Non-representative quantum mechanical weak values
B. E. Y. Svensson
2015-03-06T23:59:59.000Z
The operational definition of a weak value for a quantum mechanical system involves the limit of the weak measurement strength tending to zero. I study how this limit compares to the situation for the undisturbed (no weak measurement) system. Under certain conditions, which I investigate, this limit is discontinuous in the sense that it does not merge smoothly to the Hilbert space description of the undisturbed system. Hence, in these discontinuous cases, the weak value does not represent the undisturbed system. As a result, conclusions drawn from such weak values regarding the properties of the studied system cannot be upheld. Examples are given.
A Global Optimization Approach to Quantum Mechanics
Xiaofei Huang
2006-05-25T23:59:59.000Z
This paper presents a global optimization approach to quantum mechanics, which describes the most fundamental dynamics of the universe. It suggests that the wave-like behavior of (sub)atomic particles could be the critical characteristic of a global optimization method deployed by nature so that (sub)atomic systems can find their ground states corresponding to the global minimum of some energy function associated with the system. The classic time-independent Schrodinger equation is shown to be derivable from the global optimization method to support this argument.
Scattering in PT-symmetric quantum mechanics
Cannata, Francesco [Istituto Nazionale di Fisica Nucleare, Sezione di Bologna and Dipartimento di Fisica dell' Universita, Via Irnerio 46, I 40126 Bologna (Italy)]. E-mail: Francesco.Cannata@bo.infn.it; Dedonder, Jean-Pierre [GMPIB Universite Paris 7 - Denis-Diderot, 2 Place Jussieu, F-75251, Paris Cedex 05 (France)]. E-mail: dedonder@paris7.jussieu.fr; Ventura, Alberto [Ente Nuove Tecnologie, Energia e Ambiente, Bologna and Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy)]. E-mail: Alberto.Ventura@bologna.enea.it
2007-02-15T23:59:59.000Z
A general formalism is worked out for the description of one-dimensional scattering in non-hermitian quantum mechanics and constraints on transmission and reflection coefficients are derived in the cases of P, T or PT invariance of the Hamiltonian. Applications to some solvable PT-symmetric potentials are shown in detail. Our main original results concern the association of reflectionless potentials with asymptotic exact PT symmetry and the peculiarities of separable kernels of non-local potentials in connection with Hermiticity, T invariance and PT invariance.
Larkin, Teresa L.
Materials* Yan Wang** and Teresa L. Hein American University In this paper we will present our experiences using a portion of the materials developed by the Visual Quantum Mechanics (VQM) project1 as part of our materials were utilized in a new second-tier introductory course for non-science majors at American
Is Fresnel Optics Quantum Mechanics in Phase Space?
O. Crasser; H. Mack; W. P. Schleich
2004-02-17T23:59:59.000Z
We formulate and argue in favor of the following conjecture: There exists an intimate connection between Wigner's quantum mechanical phase space distribution function and classical Fresnel optics.
Quantum mechanics and the direction of time
Hasegawa, H.; Petrosky, T. (Univ. of Texas, Austin (United States)); Prigogine, I. (Univ. of Texas, Austin (United States) International Solvay Inst. for Physics and Chemistry, Brussels (Belgium)); Tasaki, S. (International Solvay Inst. for Physics and Chemistry, Brussels (Belgium))
1991-03-01T23:59:59.000Z
In recent papers the authors have discussed the dynamical properties of large Poincare systems (LPS), that is, nonintegrable systems with a continuous spectrum (both classical and quantum). An interesting example of LPS is given by the Friedrichs model of field theory. As is well known, perturbation methods analytic in the coupling constant diverge because of resonant denominators. They show that this Poincare catastrophe can be eliminated by a natural time ordering of the dynamical states. They obtain then a dynamical theory which incorporates a privileged direction of time (and therefore the second law of thermodynamics). However, it is only in very simple situations that his time ordering can be performed in an extended Hilbert space. In general, they need to go to the Liouville space (superspace) and introduce a time ordering of dynamical states according to the number of particles involved in correlations. This leads then to a generalization of quantum mechanics in which the usual Heisenberg's eigenvalue problem is replaced by a complex eigenvalue problem in the Liouville space.
A Causal Net Approach to Relativistic Quantum Mechanics
R. D. Bateson
2012-05-13T23:59:59.000Z
In this paper we discuss a causal network approach to describing relativistic quantum mechanics. Each vertex on the causal net represents a possible point event or particle observation. By constructing the simplest causal net based on Reichenbach-like conjunctive forks in proper time we can exactly derive the 1+1 dimension Dirac equation for a relativistic fermion and correctly model quantum mechanical statistics. Symmetries of the net provide various quantum mechanical effects such as quantum uncertainty and wavefunction, phase, spin, negative energy states and the effect of a potential. The causal net can be embedded in 3+1 dimensions and is consistent with the conventional Dirac equation. In the low velocity limit the causal net approximates to the Schrodinger equation and Pauli equation for an electromagnetic field. Extending to different momentum states the net is compatible with the Feynman path integral approach to quantum mechanics that allows calculation of well known quantum phenomena such as diffraction.
Tampering detection system using quantum-mechanical systems
Humble, Travis S. (Knoxville, TN); Bennink, Ryan S. (Knoxville, TN); Grice, Warren P. (Oak Ridge, TN)
2011-12-13T23:59:59.000Z
The use of quantum-mechanically entangled photons for monitoring the integrity of a physical border or a communication link is described. The no-cloning principle of quantum information science is used as protection against an intruder's ability to spoof a sensor receiver using a `classical` intercept-resend attack. Correlated measurement outcomes from polarization-entangled photons are used to protect against quantum intercept-resend attacks, i.e., attacks using quantum teleportation.
Green's Functions and Their Applications to Quantum Mechanics
Morrow, James A.
Green's Functions and Their Applications to Quantum Mechanics Jeff Schueler June 2, 2011 Contents 1 Green's Functions in Quantum Mechanics and Many-body Theory 8 3.1 Time Independent Green's Fuctions . . . . . . . . . . . . . . 8 3.2 Solving the Schr¨odinger Equation Using Green's Functions . . 12 4 Conclusion 13 1 #12
Environment-Induced Decoherence in Noncommutative Quantum Mechanics
Joao Nuno Prata; Nuno Costa Dias
2006-12-02T23:59:59.000Z
We address the question of the appearence of ordinary quantum mechanics in the context of noncommutative quantum mechanics. We obtain the noncommutative extension of the Hu-Paz-Zhang master equation for a Brownian particle linearly coupled to a bath of harmonic oscillators. We consider the particular case of an Ohmic regime.
Highlighting the mechanism of the quantum speedup by time-symmetric and relational quantum mechanics
Giuseppe Castagnoli
2014-12-11T23:59:59.000Z
Bob hides a ball in one of four drawers. Alice is to locate it. Classically she has to open up to three drawers, quantally just one. The fundamental reason for this quantum speedup is not known. We explain it by extending the usual representation of the quantum algorithm, limited to the process of solving the problem, to the process of setting the problem. The number of the drawer with the ball becomes a unitary transformation of the random outcome of the preparation measurement. This brings in relational quantum mechanics: the extension is with respect to Bob and cannot be with respect to Alice. It would tell her the drawer number before she opens any drawer. To Alice, the projection of the quantum state due to the preparation measurement should be retarded at the end of her search; in the input state of the search, the drawer number is determined to Bob and undetermined to Alice. A second consequence is the emergence of an ambiguity. Either the preparation measurement or the final one required to read the solution selects the solution. For reasons of symmetry, we assume that the selection shares evenly between the two measurements. All is as if Alice, by reading the solution, selected half of the information that specifies the drawer number. This selection leaves the input state to Bob unaltered and projects that to Alice on a state of lower entropy where she knows that half in advance. The quantum algorithm is a sum over histories in each of which Alice knows in advance that the ball is in a pair of drawers and locates it by opening one of the two. More in general, given an oracle problem, this explanation of the speedup predicts the number of queries required to solve it in an optimal quantum way.
A quantum mechanical version of Price's theorem for Gaussian states
Igor G. Vladimirov
2014-09-15T23:59:59.000Z
This paper is concerned with integro-differential identities which are known in statistical signal processing as Price's theorem for expectations of nonlinear functions of jointly Gaussian random variables. We revisit these relations for classical variables by using the Frechet differentiation with respect to covariance matrices, and then show that Price's theorem carries over to a quantum mechanical setting. The quantum counterpart of the theorem is established for Gaussian quantum states in the framework of the Weyl functional calculus for quantum variables satisfying the Heisenberg canonical commutation relations. The quantum mechanical version of Price's theorem relates the Frechet derivative of the generalized moment of such variables with respect to the real part of their quantum covariance matrix with other moments. As an illustrative example, we consider these relations for quadratic-exponential moments which are relevant to risk-sensitive quantum control.
Information Security and Quantum Mechanics: Security of Quantum Protocols
P. Oscar Boykin
2002-10-28T23:59:59.000Z
The problem of security of quantum key protocols is examined. In addition to the distribution of classical keys, the problem of encrypting quantum data and the structure of the operators which perform quantum encryption is studied. It is found that unitary bases are central to both encryption of quantum information, as well as the generation of states used in generalized quantum key distribution (which are called mutually unbiased bases). A one-to-one correspondence between certain unitary bases and mutually unbiased bases is found. Finally, a new protocol for making anonymous classical broadcasts is given along with a security proof. An experimental procedure to implement this protocol is also given. In order to prove these new results, some new bounds for accessible information of quantum sources are obtained.
A Process Algebra Approach to Quantum Mechanics
William H. Sulis
2014-09-07T23:59:59.000Z
The process approach to NRQM offers a fourth framework for the quantization of physical systems. Unlike the standard approaches (Schrodinger-Heisenberg, Feynman, Wigner-Gronewald-Moyal), the process approach is not merely equivalent to NRQM and is not merely a re-interpretation. The process approach provides a dynamical completion of NRQM. Standard NRQM arises as a asymptotic quotient by means of a set-valued process covering map, which links the process algebra to the usual space of wave functions and operators on Hilbert space. The process approach offers an emergentist, discrete, finite, quasi-non-local and quasi-non-contextual realist interpretation which appears to resolve many of the paradoxes and is free of divergences. Nevertheless, it retains the computational power of NRQM and possesses an emergent probability structure which agrees with NRQM in the asymptotic quotient. The paper describes the process algebra, the process covering map for single systems and the configuration process covering map for multiple systems. It demonstrates the link to NRQM through a toy model. Applications of the process algebra to various quantum mechanical situations - superpositions, two-slit experiments, entanglement, Schrodinger's cat - are presented along with an approach to the paradoxes and the issue of classicality.
High-efficiency quantum state transfer and quantum memory using a mechanical oscillator
Eyob A. Sete; H. Eleuch
2015-03-30T23:59:59.000Z
We analyze an optomechanical system that can be used to efficiently transfer a quantum state between an optical cavity and a distant mechanical oscillator coupled to a second optical cavity. We show that for a moderate mechanical Q-factor it is possible to achieve a transfer efficiency of $99.4\\%$ by using adjustable cavity damping rates and destructive interference. We also show that the quantum mechanical oscillator can be used as a quantum memory device with an efficiency of $96\\%$ employing a pulsed optomechanical coupling. Although the mechanical dissipation slightly decreases the efficiency, its effect can be significantly reduced by designing a high-Q mechanical oscillator.
Goddard III, William A.
Mechanism of Selective Oxidation of Propene to Acrolein on Bismuth Molybdates from Quantum for understanding the fundamental chemical mechanisms underlying the selective oxidation of propene to acrolein to form acrolein, and acrolein desorption. The formation of -allyl intermediate is reversible
Numerical integration of functions originating from quantum mechanics
Armiento, Rickard
Numerical integration of functions originating from quantum mechanics R. Armiento Department Applications in quantum physics commonly involve large batches of integrals of smooth but very oscillatory for evaluating such integrals. The routines studied include: two from the QUADPACK package based on Gauss
Born series and unitarity in noncommutative quantum mechanics
Bemfica, F. S.; Girotti, H. O. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970 - Porto Alegre, Rio Grande do Sul (Brazil)
2008-01-15T23:59:59.000Z
This paper is dedicated to present model independent results for noncommutative quantum mechanics. We determine sufficient conditions for the convergence of the Born series and, in the sequel, unitarity is proved in full generality.
Nonlinear coupling of nano mechanical resonators to Josephson quantum circuits
Xingxiang Zhou; Ari Mizel
2006-05-01T23:59:59.000Z
We propose a technique to couple the position operator of a nano mechanical resonator to a SQUID device by modulating its magnetic flux bias. By tuning the magnetic field properly, either linear or quadratic couplings can be realized, with a discretely adjustable coupling strength. This provides a way to realize coherent nonlinear effects in a nano mechanical resonator by coupling it to a Josephson quantum circuit. As an example, we show how squeezing of the nano mechanical resonator state can be realized with this technique. We also propose a simple method to measure the uncertainty in the position of the nano mechanical resonator without quantum state tomography.
Sensible Quantum Mechanics: Are Probabilities only in the Mind?
Don N. Page
1995-07-11T23:59:59.000Z
Quantum mechanics may be formulated as {\\it Sensible Quantum Mechanics} (SQM) so that it contains nothing probabilistic except conscious perceptions. Sets of these perceptions can be deterministically realized with measures given by expectation values of positive-operator-valued {\\it awareness operators}. Ratios of the measures for these sets of perceptions can be interpreted as frequency-type probabilities for many actually existing sets. These probabilities generally cannot be given by the ordinary quantum ``probabilities'' for a single set of alternatives. {\\it Probabilism}, or ascribing probabilities to unconscious aspects of the world, may be seen to be an {\\it aesthemamorphic myth}.
Quantum network of superconducting qubits through opto-mechanical interface
Zhang-qi Yin; W. L. Yang; L. Sun; L. M. Duan
2015-01-08T23:59:59.000Z
We propose a scheme to realize quantum networking of superconducting qubits based on the opto-mechanical interface. The superconducting qubits interact with the microwave photons, which then couple to the optical photons through the opto-mechanical interface. The interface generates a quantum link between superconducting qubits and optical flying qubits with tunable pulse shapes and carrier frequencies, enabling transmission of quantum information to other superconducting or atomic qubits. We show that the scheme works under realistic experimental conditions and it also provides a way for fast initialization of the superconducting qubits under 1 K instead of 20 mK operation temperature.
Assessing the Montevideo Interpretation of Quantum Mechanics
Jeremy Butterfield
2014-06-17T23:59:59.000Z
This paper gives a philosophical assessment of the Montevideo interpretation of quantum theory, advocated by Gambini, Pullin and co-authors. This interpretation has the merit of linking its proposal about how to solve the measurement problem to the search for quantum gravity: namely by suggesting that quantum gravity makes for fundamental limitations on the accuracy of clocks, which imply a type of decoherence that "collapses the wave-packet". I begin (Section 2) by sketching the topics of decoherence, and quantum clocks, on which the interpretation depends. Then I expound the interpretation, from a philosopher's perspective (Sections 3, 4 and 5). Finally, in Section 6, I argue that the interpretation, at least as developed so far, is best seen as a form of the Everett interpretation: namely with an effective or approximate branching, that is induced by environmental decoherence of the familiar kind, and by the Montevideans' "temporal decoherence".
Lee, Sang-Bong
1993-09-01T23:59:59.000Z
Quantum manifestation of classical chaos has been one of the extensively studied subjects for more than a decade. Yet clear understanding of its nature still remains to be an open question partly due to the lack of a canonical definition of quantum chaos. The classical definition seems to be unsuitable in quantum mechanics partly because of the Heisenberg quantum uncertainty. In this regard, quantum chaos is somewhat misleading and needs to be clarified at the very fundamental level of physics. Since it is well known that quantum mechanics is more fundamental than classical mechanics, the quantum description of classically chaotic nature should be attainable in the limit of large quantum numbers. The focus of my research, therefore, lies on the correspondence principle for classically chaotic systems. The chaotic damped driven pendulum is mainly studied numerically using the split operator method that solves the time-dependent Schroedinger equation. For classically dissipative chaotic systems in which (multi)fractal strange attractors often emerge, several quantum dissipative mechanisms are also considered. For instance, Hoover`s and Kubo-Fox-Keizer`s approaches are studied with some computational analyses. But the notion of complex energy with non-Hermiticity is extensively applied. Moreover, the Wigner and Husimi distribution functions are examined with an equivalent classical distribution in phase-space, and dynamical properties of the wave packet in configuration and momentum spaces are also explored. The results indicate that quantum dynamics embraces classical dynamics although the classicalquantum correspondence fails to be observed in the classically chaotic regime. Even in the semi-classical limits, classically chaotic phenomena would eventually be suppressed by the quantum uncertainty.
Quantum Statistical Mechanics. II. Stochastic Schrodinger Equation
Phil Attard
2014-06-02T23:59:59.000Z
The stochastic dissipative Schrodinger equation is derived for an open quantum system consisting of a sub-system able to exchange energy with a thermal reservoir. The resultant evolution of the wave function also gives the evolution of the density matrix, which is an explicit, stochastic form of the Lindblad master equation. A quantum fluctuation-dissipation theorem is also derived. The time correlation function is discussed.
Whether quantum mechanics can be almighty even in information science
Koji Nagata; Tadao Nakamura
2008-11-28T23:59:59.000Z
We discuss that there is a crucial contradiction within quantum mechanics. We derive a proposition concerning a quantum expectation value under the assumption of the existence of the directions in a spin-1/2 system. The quantum predictions within the formalism of von Neumann's projective measurement cannot coexist with the proposition concerning the existence of the directions. Therefore, we have to give up either the existence of the directions or the formalism of von Neumann's projective measurement. Hence there is a crucial contradiction within the Hilbert space formalism of the quantum theory. This implies that there is no axiomatic system for the quantum theory. This also reveals that we need new physical theories in order to explain the handing of raw experimental data. We discuss that this crucial contradiction makes the quantum-theoretical formulation of Deutsch's algorithm questionable.
The M\\"obius Symmetry of Quantum Mechanics
Faraggi, Alon E
2015-01-01T23:59:59.000Z
The equivalence postulate approach to quantum mechanics aims to formulate quantum mechanics from a fundamental geometrical principle. Underlying the formulation there exists a basic cocycle condition which is invariant under $D$--dimensional M\\"obius transformations with respect to the Euclidean or Minkowski metrics. The invariance under global M\\"obius transformations implies that spatial space is compact. Furthermore, it implies energy quantisation and undefinability of quantum trajectories without assuming any prior interpretation of the wave function. The approach may be viewed as conventional quantum mechanics with the caveat that spatial space is compact, as dictated by the M\\"obius symmetry, with the classical limit corresponding to the decompactification limit. Correspondingly, there exists a finite length scale in the formalism and consequently an intrinsic regularisation scheme. Evidence for the compactness of space may exist in the cosmic microwave background radiation.
Quantum mechanical Hamiltonian models of the computation process
Benioff, P.
1983-01-01T23:59:59.000Z
As noted in the proceedings of this conference it is of importance to determine if quantum mechanics imposes fundamental limits on the computation process. Some aspects of this problem have been examined by the development of different types of quantum mechanical Hamiltonian models of Turing machines. (Benioff 1980, 1982a, 1982b, 1982c). Turing machines were considered because they provide a standard representation of all digital computers. Thus, showing the existence of quantum mechanical models of all Turing machines is equivalent to showing the existence of quantum mechanical models of all digital computers. The types of models considered all had different properties. Some were constructed on two-dimensional lattices of quantum spin systems of spin 1/2 (Benioff 1982b, 1982c) or higher spins (Benioff 1980). All the models considered Turing machine computations which were made reversible by addition of a history tape. Quantum mechanical models of Bennett's reversible machines (Bennett 1973) in which the model makes a copy of the computation result and then erases the history and undoes the computation in lockstep to recover the input were also developed (Benioff 1982a). To avoid technical complications all the types of models were restricted to modelling an arbitrary but finite number of computation steps.
Towards Quantifying Complexity with Quantum Mechanics
Ryan Tan; Daniel R. Terno; Jayne Thompson; Vlatko Vedral; Mile Gu
2014-09-23T23:59:59.000Z
While we have intuitive notions of structure and complexity, the formalization of this intuition is non-trivial. The statistical complexity is a popular candidate. It is based on the idea that the complexity of a process can be quantified by the complexity of its simplest mathematical model - the model that requires the least past information for optimal future prediction. Here we review how such models, known as $\\epsilon$-machines can be further simplified through quantum logic, and explore the resulting consequences for understanding complexity. In particular, we propose a new measure of complexity based on quantum $\\epsilon$-machines. We apply this to a simple system undergoing constant thermalization. The resulting quantum measure of complexity aligns more closely with our intuition of how complexity should behave.
Quantum micro-mechanics with ultracold atoms
Thierry Botter; Daniel Brooks; Subhadeep Gupta; Zhao-Yuan Ma; Kevin L. Moore; Kater W. Murch; Tom P. Purdy; Dan M. Stamper-Kurn
2008-10-21T23:59:59.000Z
In many experiments isolated atoms and ions have been inserted into high-finesse optical resonators for the study of fundamental quantum optics and quantum information. Here, we introduce another application of such a system, as the realization of cavity optomechanics where the collective motion of an atomic ensemble serves the role of a moveable optical element in an optical resonator. Compared with other optomechanical systems, such as those incorporating nanofabricated cantilevers or the large cavity mirrors of gravitational observatories, our cold-atom realization offers direct access to the quantum regime. We describe experimental investigations of optomechanical effects, such as the bistability of collective atomic motion and the first quantification of measurement backaction for a macroscopic object, and discuss future directions for this nascent field.
SISSA/ISAS/100/93/EP Quantum mechanics and quantum
;b and Dingping Li a International School for Advanced studies, SISSA, IÂ34014 Trieste, Italy a Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Trieste, Trieste, Italy b Abstract The quantum mechanics
A deformation quantization theory for noncommutative quantum mechanics
Costa Dias, Nuno; Prata, Joao Nuno [Departamento de Matematica, Universidade Lusofona de Humanidades e Tecnologias, Av. Campo Grande, 376, 1749-024 Lisboa (Portugal) and Grupo de Fisica Matematica, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Gosson, Maurice de [NuHAG Fakultaet fuer Mathematik, Universitaet Wien, Wien 1090 (Austria); Luef, Franz [NuHAG Fakultaet fuer Mathematik, Universitaet Wien, Wien 1090 (Austria); Department of Mathematics, UC Berkeley, 847 Evans Hall, Berkeley, California 94720-3840 (United States)
2010-07-15T23:59:59.000Z
We show that the deformation quantization of noncommutative quantum mechanics previously considered by Dias and Prata ['Weyl-Wigner formulation of noncommutative quantum mechanics', J. Math. Phys. 49, 072101 (2008)] and Bastos, Dias, and Prata ['Wigner measures in non-commutative quantum mechanics', e-print arXiv:math-ph/0907.4438v1; Commun. Math. Phys. (to appear)] can be expressed as a Weyl calculus on a double phase space. We study the properties of the star-product thus defined and prove a spectral theorem for the star-genvalue equation using an extension of the methods recently initiated by de Gosson and Luef ['A new approach to the *-genvalue equation', Lett. Math. Phys. 85, 173-183 (2008)].
Comment on 'Nonlocality, Counterfactuals and Quantum Mechanics'
Stapp, H.P.
1999-04-14T23:59:59.000Z
A recent proof [H. P. Stapp, Am. J. Phys. 65, 300 (1997)], formulated in the symbolic language of modal logic, claims to show that contemporary quantum theory, viewed as a set of rules that allow us to calculate statistical predictions among certain kinds of observations, cannot be imbedded in any rational framework that conforms to the principles that (1) the experimenters' choices of which experiments they will perform can be considered to be free choices, (2) outcomes of measurements are unique, and (3) the free choices just mentioned have no backward-in-time effects of any kind. This claim is similar to Bell's theorem, but much stronger, because no reality assumption alien to quantum philosophy is used. The paper being commented on [W. Unruh, Phys. Rev. A 59, 126 (1999)] argues that some such reality assumption has been ''smuggled'' in. That argument is examined here and shown, I believe, to be defective.
Mind-Body Interpretation of Quantum Mechanics
Raoul Nakhmanson
2001-11-13T23:59:59.000Z
The wave-particle duality is a mind-body one. In the real 3D-space there exists only the particle, the wave exists in its consciousness. If there are many particles, their distribution in accordance with the wave function represents a real wave in real space. Many worlds, Schroedinger cat, etc., exist only as mental constructions. The "waves of matter" are non-material. Feynman et al. taught quantum world "is like neither". Alas, they forgot living matter.
Bell's Experiment in Quantum Mechanics and Classical Physics
Tom Rother
2013-08-21T23:59:59.000Z
Both the quantum mechanical and classical Bells experiment are within the focus of this paper. The fact that one measures different probabilities in both experiments is traced back to the superposition of two orthogonal but nonentangled substates in the quantum mechanical case. This superposition results in an interference term that can be splitted into two additional states representing a sink and a source of probabilities in the classical event space related to Bells experiment. As a consequence, a statistical operator can be related to the quantum mechanical Bells experiment that contains already negative quasi probabilities, as usually known from quantum optics in conjunction with the Glauber-Sudarshan equation. It is proven that the existence of such negative quasi probabilities are neither a sufficient nor a necessary condition for entanglement. The equivalence of using an interaction picture in a fixed basis or of employing a change of basis to describe Bells experiment is demonstrated afterwards. The discussion at the end of this paper regarding the application of the complementarity principle to the quantum mechanical Bells experiment is supported by very recent double slit experiments performed with polarization entangled photons.
Quantum Mechanics and Discrete Time from "Timeless" Classical Dynamics
H. -T. Elze
2003-07-03T23:59:59.000Z
We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless'' reparametrization invariant model of a relativistic particle with two compactified extradimensions. In this example, discrete physical time is constructed based on quasi-local observables. - Generally, employing the path-integral formulation of classical mechanics developed by Gozzi et al., we show that these deterministic classical systems can be naturally described as unitary quantum mechanical models. The emergent quantum Hamiltonian is derived from the underlying classical one. It is closely related to the Liouville operator. We demonstrate in several examples the necessity of regularization, in order to arrive at quantum models with bounded spectrum and stable groundstate.
Spin-Statistics Connection for Relativistic Quantum Mechanics
A. F. Bennett
2015-04-20T23:59:59.000Z
The spin-statistics connection has been proved for nonrelativistic quantum mechanics (Jabs, A., 2010: Found. Phys., {\\bf 40}, 776-792). The proof is extended here to the relativistic regime using the parametrized Dirac equation. A causality condition is not required.
Quantum-mechanical theory of optomechanical Brillouin cooling
Tomes, Matthew; Bahl, Gaurav; Carmon, Tal [Department of Electrical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Marquardt, Florian [Institut fuer Theoretische Physik, Universitaet Erlangen-Nuernberg, Staudtstrasse 7, D-91058 Erlangen (Germany); Max Planck Institute for the Science of Light, Guenther-Scharowsky-Strasse 1/Bau 24, D-91058 Erlangen (Germany)
2011-12-15T23:59:59.000Z
We analyze how to exploit Brillouin scattering of light from sound for the purpose of cooling optomechanical devices and present a quantum-mechanical theory for Brillouin cooling. Our analysis shows that significant cooling ratios can be obtained with standard experimental parameters. A further improvement of cooling efficiency is possible by increasing the dissipation of the optical anti-Stokes resonance.
Graphene and Quantum Mechanics University of California, Berkeley
Zworski, Maciej
Graphene and Quantum Mechanics Minjae Lee University of California, Berkeley lee.minjae@math.berkeley.edu March 31, 2014 Minjae Lee (UC Berkeley) Graphene March 31, 2014 1 / 9 #12;Carbon structures Graphite 3 Berkeley) Graphene March 31, 2014 2 / 9 #12;Graphene Graphene A single layer of graphite The thinnest 2D
Transition state theory, Siegert eigenstates, and quantum mechanical reaction rates
Miller, William H.
Transition state theory, Siegert eigenstates, and quantum mechanical reaction rates Tamar Seideman variables associated with a transition state (i.e., the saddle point of a potential energy surface), on which a general semiclassical transition state theory is based, are shown to be the semiclassical
Lagrangian Approaches of Dirac and Feynman to Quantum Mechanics
Y. G. Yi
2006-03-23T23:59:59.000Z
A unified exposition of the Lagrangian approach to quantum mechanics is presented, embodying the main features of the approaches of Dirac and of Feynman. The arguments of the exposition address the relation of the Lagrangian approach to the Hamiltonian operator and how the correspondence principle fits into each context.
Harmonic Superfields in N=4 Supersymmetric Quantum Mechanics
Evgeny A. Ivanov
2011-02-11T23:59:59.000Z
This is a brief survey of applications of the harmonic superspace methods to the models of N=4 supersymmetric quantum mechanics (SQM). The main focus is on a recent progress in constructing SQM models with couplings to the background non-Abelian gauge fields. Besides reviewing and systemizing the relevant results, we present some new examples and make clarifying comments.
Quantum statistics as geometry: Conflict, Mechanism, Interpretation, and Implication
Daniel C. Galehouse
2015-01-29T23:59:59.000Z
The conflict between the determinism of geometry in general relativity and the essential statistics of quantum mechanics blocks the development of a unified theory. Electromagnetic radiation is essential to both fields and supplies a common meeting ground. It is proposed that a suitable mechanism to resolve these differences can be based on the use of a time-symmetric treatment for the radiation. Advanced fields of the absorber can be interpreted to supply the random character of spontaneous emission. This allows the statistics of the Born rule to come from the spontaneous emission that occurs during a physical measurement. When the absorber is included, quantum mechanics is completely deterministic. It is suggested that the peculiar properties of kaons may be induced by the advanced effects of the neutrino field. Schr\\"odinger's cat loses its enigmatic personality and the identification of mental processes as an essential component of a measurement is no longer needed.
Noncommutative unification of general relativity and quantum mechanics
Heller, Michael; Pysiak, Leszek; Sasin, Wieslaw [Vatican Observatory, Vatican City, V-00120 Vatican City, Rome (Italy); Department of Mathematics and Information Science, Warsaw University of Technology, Plac Politechniki 1, 00-661 Warsaw (Poland)
2005-12-15T23:59:59.000Z
We present a model unifying general relativity and quantum mechanics based on a noncommutative geometry. This geometry is developed in terms of a noncommutative algebra A which is defined on a transformation groupoid {gamma} given by the action of a noncompact group G on the total space E of a principal fiber bundle over space-time M. The case is important since to obtain physical effects predicted by the model we should assume that G is a Lorentz group or some of its representations. We show that the generalized Einstein equation of the model has the form of the eigenvalue equation for the generalized Ricci operator, and all relevant operators in the quantum sector of the model are random operators; we study their dynamics. We also show that the model correctly reproduces general relativity and the usual quantum mechanics. It is interesting that the latter is recovered by performing the measurement of any observable. In the act of such a measurement the model 'collapses' to the usual quantum mechanics.
New version of $q$-deformed supersymmetric quantum mechanics
Gavrilik, A M; Lukash, A V
2013-01-01T23:59:59.000Z
A new version of the q-deformed supersymmetric quantum mechanics (q-SQM), which is inspired by the Tamm--Dankoff-type (TD-type) deformation of quantum harmonic oscillator, is constructed. The obtained algebra of q-SQM is similar to that in Spiridonov's approach. However, within our version of q-SQM, the ground state found explicitly in the special case of superpotential yiealding q-superoscillator turns out to be non-Gaussian and takes the form of special (TD-type) q-deformed Gaussian.
On a Model of Quantum Mechanics and the Mind
J. Acacio de Barros
2014-04-16T23:59:59.000Z
In this paper I discuss Stapp's (2014) interesting proposal of using the Quantum Zeno Effect to account for the mind/matter interaction. In particular, I discuss some of the motivations for it, and then argue that, in his current version, his model is circular (a solution to this, proposed by Kathryn Laskey, is presented), insofar as the mind/matter problem is concerned. I also present an alternative approach to some of the appealing aspects of using quantum mechanics to think about consciousness.
Quantum mechanical perspectives and generalization of the fractional Fourier Transformation
Jun-Hua Chen; Hong-Yi Fan
2014-08-23T23:59:59.000Z
Fourier and fractional-Fourier transformations are widely used in theoretical physics. In this paper we make quantum perspectives and generalization for the fractional Fourier transformation (FrFT). By virtue of quantum mechanical representation transformation and the method of integration within normal ordered product (IWOP) of operators, we find the key point for composing FrFT, and reveal the structure of FrFT. Following this procedure, a full family of generalized fractional transformations are discovered with the usual FrFT as one special case. The eigen-functions of arbitrary GFrT are derived explicitly.
Substrate Hydroxylation in Methane Monooxygenase: Quantitative Modeling via Mixed Quantum Mechanics/
Gherman, Benjamin F.
at an atomic level of detail.4-7 In particular, the use of ab initio quantum chemical methods based on densitySubstrate Hydroxylation in Methane Monooxygenase: Quantitative Modeling via Mixed Quantum Mechanics with mixed quantum mechanics/molecular mechanics (QM/MM) methods, the hydroxylation of methane
Bell's theorem tells us NOT what quantum mechanics IS, but what quantum mechanics IS NOT
Zukowski, Marek
2015-01-01T23:59:59.000Z
Non-locality, or quantum-non-locality, are buzzwords in the community of quantum foundation and information scientists, which purportedly describe the implications of Bell's theorem. When such phrases are treated seriously, that is it is claimed that Bell's theorem reveals non-locality as an inherent trait of the quantum description of the micro-world, this leads to logical contradictions, which will be discussed here. In fact, Bell's theorem, understood as violation of Bell inequalities by quantum predictions, is consistent with Bohr's notion of complementarity. Thus, if it points to anything, then it is rather the significance of the principle of Bohr, but even this is not a clear implication. Non-locality is a necessary consequence of Bell's theorem only if we reject complementarity by adopting some form of realism, be it additional hidden variables, additional hidden causes, etc., or counterfactual definiteness. The essay contains two largely independent parts. The first one is addressed to any reader int...
The Measurement Problem and the Reduction Postulate of Quantum Mechanics
Rodolfo Gambini
1998-06-18T23:59:59.000Z
It is well known, that the causal Schr\\"odinger evolution of a quantum state is not compatible with the reduction postulate, even when decoherence is taken into account. The violation of the causal evolution, introduced by the standard reduction postulate distinguishes certain systems (as the measurement devices), whose states are very close to statistical mixtures (as the ones resulting from the process of decoherence). In these systems, this violation has not any observable effect. In arbitrary quantum systems, the transition from the initial density matrix to a diagonal matrix predicted by the standard reduction postulate, would lead to a complete breakdown of the Schr\\"odinger evolution, and consequently would destroy all the predictive power of quantum mechanics. What we show here, is that there is a modified version of the postulate that allows to treat all the quantum mechanical systems on equal footing. The standard reduction postulate may be considered as a good approximation, useful for practical purposes, of this modified version which is consistent with the Schr\\"odinger evolution and via decoherence with the experimental results. Within this approach, the physical role played by the reduction postulate is as a tool for the computation of relative probabilities and consequently for the determination of the probabilities of consistent histories.
Zero-Branes, Quantum Mechanics and the Cosmological Constant
Andrew Chamblin; Neil D. Lambert
2001-07-25T23:59:59.000Z
We analyse some dynamical issues in a modified type IIA supergravity, recently proposed as an extension of M-theory that admits de Sitter space. In particular we find that this theory has multiple zero-brane solutions. This suggests a microscopic quantum mechanical matrix description which yields a massive deformation of the usual M(atrix) formulation of M-theory and type IIA string theory.
Noncommutative Field Theory from Quantum Mechanical Space-Space Noncommutativity
Marcos Rosenbaum; J. David Vergara; L. Roman Juarez
2007-09-21T23:59:59.000Z
We investigate the incorporation of space noncommutativity into field theory by extending to the spectral continuum the minisuperspace action of the quantum mechanical harmonic oscillator propagator with an enlarged Heisenberg algebra. In addition to the usual $\\star$-product deformation of the algebra of field functions, we show that the parameter of noncommutativity can occur in noncommutative field theory even in the case of free fields without self-interacting potentials.
Formulation of quantum mechanics in terms of gauge transformations
S. R. Vatsya
2014-05-29T23:59:59.000Z
Formulations of quantum mechanics incorporating the Weyl gauge transformations are studied in this article and developed further. In the process, impact of the method of observation on its outcome is interpreted in terms of the assigned gauges by incorporating properties of the corresponding experimental arrangement in defining them. Further, the assigned gauge is explicitly incorporated in the Feynman path integral formulation of quantum mechanics. The resulting wavefunction, which is not uniquely defined, represents a gauge equivalence class. The representative wavefunction is still obtained by the original path integral method. Methods to obtain the pertinent information about the assigned gauges supplementing the representative wavefunction are discussed. The probability density is shown to be a uniquely defined gauge invariant quantity but at the expense of some information describing the observable effects contained in gauge factors. In the standard quantum mechanics, a wavefunction is assumed to be defined within a phase factor while the probability density is phase-independent, paralleling these results. Also, the path integral method is used to deduce the Klein-Gordon equation for the representative wavefunction in the Riemannian spaces in a more streamlined manner than the previous derivations.
Thermodynamics and equilibrium structure of Ne38 cluster: Quantum mechanics versus classical
Mandelshtam, Vladimir A.
. For example, although the heat capacity Cv T around the "solid-liquid" transition temperature T 10 K MC simulations are implemented in the parallel tempering framework. The classical heat capacity Cv do not play an essential role in the thermodynamics of Ne38, the quantum heat capacity
Dark current mechanism of terahertz quantum-well photodetectors
Jia, J. Y.; Gao, J. H.; Hao, M. R.; Wang, T. M.; Shen, W. Z.; Zhang, Y. H., E-mail: yuehzhang@sjtu.edu.cn [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cao, J. C.; Guo, X. G. [Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050 (China); Schneider, H., E-mail: h.schneider@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, 01314 Dresden (Germany)
2014-10-21T23:59:59.000Z
Dark current mechanisms of terahertz quantum-well photodetectors (THz QWPs) are systematically investigated experimentally and theoretically by measuring two newly designed structures combined with samples reported previously. In contrast to previous investigations, scattering-assisted tunneling dark current is found to cause significant contributions to total dark current. A criterion is also proposed to determine the major dark current mechanism at different peak response frequencies. We further determine background limited performance (BLIP) temperatures, which decrease both experimentally and theoretically as the electric field increases. This work gives good description of dark current mechanism for QWPs in the THz region and is extended to determine the transition fields and BLIP temperatures with response peaks from 3 to 12 THz.
A classical, elementary approach to the foundations of Quantum Mechanics
Rodriguez, David
2011-01-01T23:59:59.000Z
Perhaps Quantum Mechanics can be seen just as the simplest mathematical formalism where angular momentum (the magnitude of each of its three orthogonal projections) is by construction quantized: all possible values are taken from a discrete set. Indeed: (i) This idea finds support in very reasonable, completely classical physical arguments, if we place ourselves in the framework of Stochastic Electrodynamics (SED): there, all sustained periodic movement must satisfy a power balance that restricts the value of the average angular momentum, on each of its projections. (ii) It gives a natural explanation of the concept of "photon", as a constraint on the observable spectrum of energy-momentum exchanges between metastable physical states, in particular its discreteness. QM would be, in this picture, a semi-static theory, transparent to all the (micro)-dynamics taking place between apparently "discrete" events (transitions in the state of the system). For instance, (the magnitude of the projections of) quantum ang...
Reality without Realism: On the Ontological and Epistemological Architecture of Quantum Mechanics
Plotnitsky, Arkady
2015-01-01T23:59:59.000Z
First, the article considers the nature of quantum reality (the reality responsible for quantum phenomena) and the concept of realism (our ability to represent this reality) in quantum theory, in conjunction with the roles of locality, causality, and probability and statistics there. Second, it offers two interpretations of quantum mechanics, developed by the authors of this article, the second of which is also a different (from quantum mechanics) theory of quantum phenomena. Both of these interpretations are statistical. The first interpretation, by A. Plotnitsky, "the statistical Copenhagen interpretation," is non-realist, insofar as the description or even conception of the nature of quantum objects and processes is precluded. The second, by A. Khrennikov, is ultimately realist, because it assumes that the quantum-mechanical level of reality is underlain by a deeper level of reality, described, in a realist fashion, by a model based on the pre-quantum classical statistical field theory (PCSFT), the predict...
Poincaré Invariant Quantum Mechanics based on Euclidean Green functions
W. N. Polyzou; Phil Kopp
2010-08-31T23:59:59.000Z
We investigate a formulation of Poincar\\'e invariant quantum mechanics where the dynamical input is Euclidean invariant Green functions or their generating functional. We argue that within this framework it is possible to calculate scattering observables, binding energies, and perform finite Poincar\\'e transformations without using any analytic continuation. We demonstrate, using a toy model, how matrix elements of $e^{-\\beta H}$ in normalizable states can be used to compute transition matrix elements for energies up to 2 GeV. We discuss some open problems.
Machine Learning for Quantum Mechanical Properties of Atoms in Molecules
Rupp, Matthias; von Lilienfeld, O Anatole
2015-01-01T23:59:59.000Z
We introduce machine learning models of quantum mechanical observables of atoms in molecules. Instant out-of-sample predictions for proton and carbon nuclear chemical shifts, atomic core level excitations, and forces on atoms reach accuracies on par with density functional theory reference. Locality is exploited within non-linear regression via local atom-centered coordinate systems. The approach is validated on a diverse set of 9k small organic molecules. Linear scaling is demonstrated for saturated polymers with up to sub-mesoscale lengths.
Twisting all the way: From classical mechanics to quantum fields
Aschieri, Paolo [Centro Studi e Ricerche 'Enrico Fermi' Compendio Viminale, 00184 Rome (Italy); Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale, and INFN, Sezione di Torino Via Bellini 25/G 15100 Alessandria (Italy); Lizzi, Fedele; Vitale, Patrizia [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II and INFN, Sezione di Napoli Monte S. Angelo, Via Cintia, 80126 Naples (Italy)
2008-01-15T23:59:59.000Z
We discuss the effects that a noncommutative geometry induced by a Drinfeld twist has on physical theories. We systematically deform all products and symmetries of the theory. We discuss noncommutative classical mechanics, in particular its deformed Poisson bracket and hence time evolution and symmetries. The twisting is then extended to classical fields, and then to the main interest of this work: quantum fields. This leads to a geometric formulation of quantization on noncommutative space-time, i.e., we establish a noncommutative correspondence principle from *-Poisson brackets to * commutators. In particular commutation relations among creation and annihilation operators are deduced.
Matrix Quantum Mechanics and Soliton Regularization of Noncommutative Field Theory
Giovanni Landi; Fedele Lizzi; Richard J. Szabo
2004-01-20T23:59:59.000Z
We construct an approximation to field theories on the noncommutative torus based on soliton projections and partial isometries which together form a matrix algebra of functions on the sum of two circles. The matrix quantum mechanics is applied to the perturbative dynamics of scalar field theory, to tachyon dynamics in string field theory, and to the Hamiltonian dynamics of noncommutative gauge theory in two dimensions. We also describe the adiabatic dynamics of solitons on the noncommutative torus and compare various classes of noncommutative solitons on the torus and the plane.
N + 1 dimensional quantum mechanical model for a closed universe
T. R. Mongan
1999-02-10T23:59:59.000Z
A quantum mechanical model for an N + 1 dimensional universe arising from a quantum fluctuation is outlined. (3 + 1) dimensions are a closed infinitely-expanding universe and the remaining N - 3 dimensions are compact. The (3 + 1) non-compact dimensions are modeled by quantizing a canonical Hamiltonian description of a homogeneous isotropic universe. It is assumed gravity and the strong-electro-weak (SEW) forces had equal strength in the initial state. Inflation occurred when the compact N -3 dimensional space collapsed after a quantum transition from the initial state of the univers, during its evolution to the present state where gravity is much weaker than the SEW force. The model suggests the universe has no singularities and the large size of our present universe is determined by the relative strength of gravity and the SEW force today. A small cosmological constant, resulting from the zero point energy of the scalar field corresponding to the compact dimensions, makes the model universe expand forever.
Quantum mechanical observer and superstring/M theory
M. Dance
2008-12-31T23:59:59.000Z
Terms are suggested for inclusion in a Lagrangian density as seen by an observer O2, to represent the dynamics of a quantum mechanical observer O1 that is an initial stage in an observation process. This paper extends an earlier paper which suggested that the centre-of-mass kinetic energy of O1 could correspond to, and possibly underlie, the Lagrangian density for bosonic string theory, where the worldsheet coordinates are the coordinates which O1 can observe. The present paper considers a fermion internal to O1, in addition to O1's centre of mass. It is suggested that quantum mechanical uncertainties in the transformation between O1's and O2's reference systems might require O2 to use $d$ spinor fields for this fermion, where $d$ is the number of spacetime dimensions. If this is the case, and if the symmetry/observability arguments in arXiv:hep-th/0601104 apply, the resulting Lagrangian density for the dynamics of O1 might resemble, or even underlie, superstring/M theory.
ECE 350 / 450 -Fall 2010 Applied Quantum Mechanics for Engineers (3)
Gilchrist, James F.
ECE 350 / 450 - Fall 2010 Applied Quantum Mechanics for Engineers (3) Instructor: Prof. Nelson (for ECE 450-level) in engineering (Electical and Computer Engineering, Material Science Engineering
Chen, Jie; Yin, Hongyun; Wang, Dunyou; Valiev, Marat
2013-02-20T23:59:59.000Z
The OH- (H2O) + CCl4 reaction in aqueous solution was investigated using the combined quantum mechanical and molecular mechanics approach. The reaction mechanism of OH- (H2O) + CCl4 consists of two concerted steps - formation of OH- in the favorable attack conformation via the proton transfer process, and the nucleophilic substitution process in which the newly formed OH- attacks the CCl4. The free energy activation barrier is 38.2 kcal/mol at CCSD(T)/MM level of theory for this reaction, which is about 10.3 kcal/mol higher than that of the direct nucleophilic substitution mechanism of the OH- + CCl4 reaction in aqueous solution.
Gogonea, V.; Merz, K.M. Jr. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemistry] [Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemistry
1999-07-01T23:59:59.000Z
In this paper the authors report a method for solving the Schroedinger equation for large molecules in solution which involved merging a linear scaling divide and conquer (D and C) semiempirical algorithm with the Poisson-Boltzmann (PB) equation. They then assess the performance of their self-consistent reaction field (SCRF) approach by comparing the D and C-PB calculations for a set of 29 neutral and 36 charged molecules with those obtained by ab initio GVB and DFT (B3LYP) methods, Cramer and Truhlar`s semiempirical generalized-Born SM5 model, and with the experimental solvation free energies. Furthermore, the authors show that their SCRF method can be used to perform fully quantum mechanical calculations of proteins in solution in a reasonable amount of time on a modern workstation. They believe that all electrostatic interactions in biological systems require a quantum mechanical description in order to obtain an accurate representation. Thus, their new SCRF method should have an impact on the computational study of physical and chemical phenomena occurring in proteins and nuclei acids, which are, in general, strongly influenced by electrostatic interactions. Moreover, this may lead to novel insights into classic problems like protein folding or drug design.
Goddard III, William A.
Quantum mechanics based force field for carbon ,,QMFF-Cx... validated to reproduce the mechanical mechanics based force field for carbon QMFF-Cx by fitting to results from density functional theory . A third, eclipsed geometry is calculated to be much higher in energy. The QMFF-Cx force field leads
A Review of Student Difficulties in Upper-Level Quantum Mechanics
Singh, Chandralekha
2015-01-01T23:59:59.000Z
Learning advanced physics, in general, is challenging not only due to the increased mathematical sophistication but also because one must continue to build on all of the prior knowledge acquired at the introductory and intermediate levels. In addition, learning quantum mechanics can be especially challenging because the paradigms of classical mechanics and quantum mechanics are very different. Here, we review research on student reasoning difficulties in learning upper-level quantum mechanics and research on students' problem-solving and metacognitive skills in these courses. Some of these studies were multi-university investigations. The investigations suggest that there is large diversity in student performance in upper-level quantum mechanics regardless of the university, textbook, or instructor and many students in these courses have not acquired a functional understanding of the fundamental concepts. The nature of reasoning difficulties in learning quantum mechanics is analogous to reasoning difficulties...
Quantum Mechanics and the Principle of Least Radix Economy
Vladimir Garcia-Morales
2015-01-08T23:59:59.000Z
A new variational method, the principle of least radix economy, is formulated. The mathematical and physical relevance of the radix economy, also called digit capacity, is established, showing how physical laws can be derived from this concept in a unified way. The principle reinterprets and generalizes the principle of least action yielding two classes of physical solutions: least action paths and quantum wavefunctions. A new physical foundation of the Hilbert space of quantum mechanics is then accomplished and it is used to derive the Schr\\"odinger and Dirac equations and the breaking of the commutativity of spacetime geometry. The formulation provides an explanation of how determinism and random statistical behavior coexist in spacetime and a framework is developed that allows dynamical processes to be formulated in terms of chains of digits. These methods lead to a new (pre-geometrical) foundation for Lorentz transformations and special relativity. The Parker-Rhodes combinatorial hierarchy is encompassed within our approach and this leads to an estimate of the interaction strength of the electromagnetic and gravitational forces that agrees with the experimental values to an error of less than one thousandth. Finally, it is shown how the principle of least-radix economy naturally gives rise to Boltzmann's principle of classical statistical thermodynamics. A new expression for a general (path-dependent) nonequilibrium entropy is proposed satisfying the Second Law of Thermodynamics.
Frame transforms, star products and quantum mechanics on phase space
P. Aniello; V. I. Man'ko; G. Marmo
2008-04-10T23:59:59.000Z
Using the notions of frame transform and of square integrable projective representation of a locally compact group $G$, we introduce a class of isometries (tight frame transforms) from the space of Hilbert-Schmidt operators in the carrier Hilbert space of the representation into the space of square integrable functions on the direct product group $G\\times G$. These transforms have remarkable properties. In particular, their ranges are reproducing kernel Hilbert spaces endowed with a suitable 'star product' which mimics, at the level of functions, the original product of operators. A 'phase space formulation' of quantum mechanics relying on the frame transforms introduced in the present paper, and the link of these maps with both the Wigner transform and the wavelet transform are discussed.
Classical and quantum-mechanical phase space distributions
Thomas Kiesel
2013-06-21T23:59:59.000Z
We examine the notion of nonclassicality in terms of quasiprobability distributions. In particular, we do not only ask if a specific quasiprobability can be interpreted as a classical probability density, but require that characteristic features of classical electrodynamics are resembled. We show that the only quasiprobabilities which correctly describe the superposition principle of classical electromagnetic fields are the $s$-parameterized quasiprobabilities. Furthermore, the Glauber-Sudarshan P function is the only quantum-mechanical quasiprobability which is transformed at a classical attenuator in the same way as a classical probability distribution. This result strengthens the definition of nonclassicality in terms of the P function, in contrast to possible definitions in terms of other quasiprobabilities.
Generally covariant quantum mechanics on noncommutative configuration spaces
Kopf, Tomas; Paschke, Mario [Mathematical Institute, Silesian University, Na Rybnicku 1, 74601 Opava (Czech Republic); Institut fuer Mathematik, Einsteinstrasse 62, 48149 Muenster (Germany)
2007-11-15T23:59:59.000Z
We generalize the previously given algebraic version of 'Feynman's proof of Maxwell's equations' to noncommutative configuration spaces. By doing so, we also obtain an axiomatic formulation of nonrelativistic quantum mechanics over such spaces, which, in contrast to most examples discussed in the literature, does not rely on a distinguished set of coordinates. We give a detailed account of several examples, e.g., C{sup {infinity}}(Q)xM{sub n}(C) which leads to non-Abelian Yang-Mills theories, and of noncommutative tori T{sub {theta}}{sup d}. Moreover, we examine models over the Moyal-deformed plane R{sub {theta}}{sup 2}. Assuming the conservation of electrical charges, we show that in this case the canonical uncertainty relation [x{sub k},x{sub l}]=ig{sub kl} with metric g{sub kl} is only consistent if g{sub kl} is constant.
CO2 Adsorption in Fe2(dobdc): A Classical Force Field Parameterized from Quantum Mechanical
Paris-Sud XI, Université de
CO2 Adsorption in Fe2(dobdc): A Classical Force Field Parameterized from Quantum Mechanical : 10.1021/jp500313j #12;Abstract Carbon dioxide adsorption isotherms have been computed for the Metal derived from quantum mechanical calculations has been used to model adsorption isotherms within a MOF
Quantum Theory of Cavity-Assisted Sideband Cooling of Mechanical Motion Florian Marquardt,1
Clerk, Aashish
using bulk refrigeration, but it may be feasible using nonequilibrium cooling techniques analo- gousQuantum Theory of Cavity-Assisted Sideband Cooling of Mechanical Motion Florian Marquardt,1 Joe P (Received 22 January 2007; published 28 August 2007) We present a quantum-mechanical theory of the cooling
Mechanism for thermoelectric figure-of-merit enhancement in regimented quantum dot superlattices
Mechanism for thermoelectric figure-of-merit enhancement in regimented quantum dot superlattices propose a mechanism for enhancement of the thermoelectric figure-of-merit in regimented quantum dot, as a result, to the thermoelectric figure-of-merit enhancement. To maximize the improvement, one has to tune
Elio Conte
2011-06-14T23:59:59.000Z
We review our approach to quantum mechanics adding also some new interesting results. We start by giving proof of two important theorems on the existence of the and Clifford algebras. This last algebra gives proof of the von Neumann basic postulates on the quantum measurement explaining thus in an algebraic manner the wave function collapse postulated in standard quantum theory. In this manner we reach the objective to expose a self-consistent version of quantum mechanics. We give proof of the quantum like Heisenberg uncertainty relations, the phenomenon of quantum Mach Zender interference as well as quantum collapse in some cases of physical interest We also discuss the problem of time evolution of quantum systems as well as the changes in space location. We also give demonstration of the Kocken-Specher theorem, and also we give an algebraic formulation and explanation of the EPR . By using the same approach we also derive Bell inequalities. Our formulation is strongly based on the use of idempotents that are contained in Clifford algebra. Their counterpart in quantum mechanics is represented by the projection operators that are interpreted as logical statements, following the basic von Neumann results. Using the Clifford algebra we are able to invert such result. According to the results previously obtained by Orlov in 1994, we are able to give proof that quantum mechanics derives from logic. We show that indeterminism and quantum interference have their origin in the logic.
State Transfer Between a Mechanical Oscillator and Microwave Fields in the Quantum Regime
T. A. Palomaki; J. W. Harlow; J. D. Teufel; R. W. Simmonds; K. W. Lehnert
2012-06-25T23:59:59.000Z
Recently, macroscopic mechanical oscillators have been coaxed into a regime of quantum behavior, by direct refrigeration [1] or a combination of refrigeration and laser-like cooling [2, 3]. This exciting result has encouraged notions that mechanical oscillators may perform useful functions in the processing of quantum information with superconducting circuits [1, 4-7], either by serving as a quantum memory for the ephemeral state of a microwave field or by providing a quantum interface between otherwise incompatible systems [8, 9]. As yet, the transfer of an itinerant state or propagating mode of a microwave field to and from a mechanical oscillator has not been demonstrated owing to the inability to agilely turn on and off the interaction between microwave electricity and mechanical motion. Here we demonstrate that the state of an itinerant microwave field can be coherently transferred into, stored in, and retrieved from a mechanical oscillator with amplitudes at the single quanta level. Crucially, the time to capture and to retrieve the microwave state is shorter than the quantum state lifetime of the mechanical oscillator. In this quantum regime, the mechanical oscillator can both store and transduce quantum information.
A nonlinear variational problem in relativistic quan-tum mechanics
Boyer, Edmond
electrodynamics, vacuum polarization Proceedings of the 6th European Congress of Mathematics, Krakow (Poland/anti-particle pair by providing a sufficient amount of energy to the vacuum. From Einstein's famous relation, this energy must be at least 2 × mc2 . Because one can create matter from energy, the vacuum cannot be seen
Supersymmetric descendants of self-adjointly extended quantum mechanical Hamiltonians
Al-Hashimi, M.H., E-mail: hashimi@itp.unibe.ch [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern University, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Salman, M., E-mail: msalman@qu.edu.qa [Department of Mathematics, Statistics, and Physics, Qatar University, Al Tarfa, Doha 2713 (Qatar); Shalaby, A., E-mail: amshalab@qu.edu.qa [Department of Mathematics, Statistics, and Physics, Qatar University, Al Tarfa, Doha 2713 (Qatar); Physics Department, Faculty of Science, Mansoura University (Egypt); Wiese, U.-J., E-mail: wiese@itp.unibe.ch [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern University, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Center for Theoretical Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA (United States)
2013-10-15T23:59:59.000Z
We consider the descendants of self-adjointly extended Hamiltonians in supersymmetric quantum mechanics on a half-line, on an interval, and on a punctured line or interval. While there is a 4-parameter family of self-adjointly extended Hamiltonians on a punctured line, only a 3-parameter sub-family has supersymmetric descendants that are themselves self-adjoint. We also address the self-adjointness of an operator related to the supercharge, and point out that only a sub-class of its most general self-adjoint extensions is physical. Besides a general characterization of self-adjoint extensions and their supersymmetric descendants, we explicitly consider concrete examples, including a particle in a box with general boundary conditions, with and without an additional point interaction. We also discuss bulk-boundary resonances and their manifestation in the supersymmetric descendant. -- Highlights: •Self-adjoint extension theory and contact interactions. •Application of self-adjoint extensions to supersymmetry. •Contact interactions in finite volume with Robin boundary condition.
A necessary and sufficient condition to play games in quantum mechanical settings
Sahin Kaya Ozdemir; Junichi Shimamura; Nobuyuki Imoto
2007-03-01T23:59:59.000Z
Quantum game theory is a multidisciplinary field which combines quantum mechanics with game theory by introducing non-classical resources such as entanglement, quantum operations and quantum measurement. By transferring two-player-two strategy (2x2) dilemma containing classical games into quantum realm, dilemmas can be resolved in quantum pure strategies if entanglement is distributed between the players who use quantum operations. Moreover, players receive the highest sum of payoffs available in the game, which are otherwise impossible in classical pure strategies. Encouraged by the observation of rich dynamics of physical systems with many interacting parties and the power of entanglement in quantum versions of 2x2 games, it became generally accepted that quantum versions can be easily extended to N-player situations by simply allowing N-partite entangled states. In this article, however, we show that this is not generally true because the reproducibility of classical tasks in quantum domain imposes limitations on the type of entanglement and quantum operators. We propose a benchmark for the evaluation of quantum and classical versions of games, and derive the necessary and sufficient conditions for a physical realization. We give examples of entangled states that can and cannot be used, and the characteristics of quantum operators used as strategies.
Cosmological Rotation of Quantum-Mechanical Origin and Anisotropy of the Microwave Background
L. P. Grishchuk
1993-10-06T23:59:59.000Z
It is shown that rotational cosmological perturbations can be generated in the early Universe, similarly to gravitational waves. The generating mechanism is quantum-mechanical in its nature, and the created perturbations should now be placed in squeezed vacuum quantum states. The physical conditions under which the phenomenon can occur are formulated. The generated perturbations can contribute to the large-angular-scale anisotropy of the cosmic microwave background radiation. An exact formula is derived for the angular correlation function of the temperature variations caused by the quantum-mechanically generated rotational perturbations. The multipole expansion begins from the dipole component. The comparison with the case of gravitational waves is made.
Reginald B. Little
2014-03-27T23:59:59.000Z
A comprehensive theory of superconductivity (SC) and superfluidity (SF) is presented of new types III and IV at temperatures into millions of degrees involving phase transitions of fermions in heat reservoirs to form general relativistic triple quasi-particles of 3 fermions interacting to boson-fermion pairs. Types 0, I, and II SC/SF are deduced from such triples as: thermally dressed, relativistic fermionic vortices; spin coupled, dressed, fermionic vortical pairs (diamagnetic bosons); and spinrevorbitally coupled, dressed fermionic, vortical pairs (ferromagnetic bosons). All known SC, SF and trends in critical temperatures (Tc) are thereby explained. The recently observed SC/SF in nano-graphene systems is explained. The above room temperature SC/SF is predicted and modeled by transformations of intense thermal boson populations of heat reservoirs to relativistic mass, weight, spin and magnetism for further reasoning over compression to electricity, weak phenomena and strong phenomena for connecting general relativism and quantum mechanics.
Reginald B. Little
2015-04-23T23:59:59.000Z
A comprehensive theory of superconductivity (SC) and superfluidity (SF) is presented of new types III and IV at temperatures into millions of degrees involving phase transitions of fermions in heat reservoirs to form general relativistic triple quasi-particles of 3 fermions interacting to boson-fermion pairs. Types 0, I, and II SC/SF are deduced from such triples as: thermally dressed, relativistic fermionic vortices; spin coupled, dressed, fermionic vortical pairs (diamagnetic bosons); and spinrevorbitally coupled, dressed fermionic, vortical pairs (ferromagnetic bosons). All known SC, SF and trends in critical temperatures (Tc) are thereby explained. The recently observed SC/SF in nano-graphene systems is explained. The above room temperature SC/SF is predicted and modeled by transformations of intense thermal boson populations of heat reservoirs to relativistic mass, weight, spin and magnetism for further reasoning over compression to electricity, weak phenomena and strong phenomena for connecting general relativism and quantum mechanics.
Quantum Ground State and Single Phonon Control of a Mechanical Resonator
Martinis, John M.
-limited measurements must then be demonstrated. Here, using conventional cryo- genic refrigeration, we show that we can, eases the stringent temperature requirements, and when combined with quantum optics-based refrigeration conventional cryogenic refrigeration, we show that we can demonstrably cool a mechanical mode to its quantum
A Short-Time Quantum Mechanical Expansion Approach to Vibrational Relaxation Eran Rabani*,
Rabani, Eran
A Short-Time Quantum Mechanical Expansion Approach to Vibrational Relaxation Eran Rabani*, School" molecule embedded in a "quantum" host is approached from the perspective of a short-time expansion that depend on both position and momentum. A simple ansatz is used to connect the short-time and long
Quantum-mechanical description of Lense-Thirring effect for relativistic scalar particles
Alexander J. Silenko
2014-08-10T23:59:59.000Z
Exact expression for the Foldy-Wouthuysen Hamiltonian of scalar particles is used for a quantum-mechanical description of the relativistic Lense-Thirring effect. The exact evolution of the angular momentum operator in the Kerr field approximated by a spatially isotropic metric is found. The quantum-mechanical description of the full Lense-Thirring effect based on the Laplace-Runge-Lenz vector is given in the nonrelativistic and weak-field approximation. Relativistic quantum-mechanical equations for the velocity and acceleration operators are obtained. The equation for the acceleration defines the Coriolis-like and centrifugal-like accelerations and presents the quantum-mechanical description of the frame-dragging effect.
Liao, Rongzhen
Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical theory Enzyme catalysis Formaldehyde ferredoxin oxidoreductase from Pyrococcus furiosus is a tungsten the formaldehyde substrate binds directly to the tungsten ion. WVI =O then performs a nucleophilic attack
Application of quantum theory of electrons to the mechanical and thermal properties of metals
Peng, Hwan-Wu
The first successful application of quantum mechanics to the problem of metallic cohesion was made by Wigner and Seitz (1938) They appoximated sodium metal by a number of isolated spheres of equal atomic volume and integrated, ...
Unitary dilation models of Turing machines in quantum mechanics
Benioff, P. [Environmental Assessment Division, Building 900, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Environmental Assessment Division, Building 900, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
1995-05-01T23:59:59.000Z
A goal of quantum-mechanical models of the computation process is the description of operators that model changes in the information-bearing degrees of freedom. Iteration of the operators should correspond to steps in the computation, and the final state of halting computations should be stable under iteration. The problem is that operators constructed directly from the process description do not have these properties. In general these operators annihilate the halted state. If information-erasing steps are present, there are additional problems. These problems are illustrated in this paper by consideration of operators for two simple one-step processes and two simple Turing machines. In general the operators are not unitary and, if erasing steps are present, they are not even contraction operators. Various methods of extension or dilation to unitary operators are discussed. Here unitary power dilations are considered as a solution to these problems. It is seen that these dilations automatically provide a good solution to the initial- and final-state problems. For processes with erasing steps, recording steps must be included prior to the dilation, but only for the steps that erase information. Hamiltonians for these processes are also discussed. It is noted that {ital H}, described by exp({minus}{ital iH}{Delta})={ital U}{sup {ital T}}, where {ital U}{sup {ital T}} is a unitary step operator for the process and {Delta} a time interval, has complexity problems. These problems and those noted above are avoided here by the use of the Feynman approach to constructing Hamiltonians directly from the unitary power dilations of the model operators. It is seen that the Hamiltonians so constructed have some interesting properties.
On the justification of applying quantum strategies to the Prisoners' Dilemma and mechanism design
Haoyang Wu
2010-07-08T23:59:59.000Z
The Prisoners' Dilemma is perhaps the most famous model in the field of game theory. Consequently, it is natural to investigate its quantum version when one considers to apply quantum strategies to game theory. There are two main results in this paper: 1) The well-known Prisoners' Dilemma can be categorized into three types and only the third type is adaptable for quantum strategies. 2) As a reverse problem of game theory, mechanism design provides a better circumstance for quantum strategies than game theory does.
Phil Attard
2013-11-25T23:59:59.000Z
The probability operator is derived from first principles for an equilibrium quantum system. It is also shown that the superposition states collapse into a mixture of states giving the conventional von Neumann trace form for the quantum average. The mechanism for the collapse is found to be quite general: it results from the conservation law for a conserved, exchangeable variable (such as energy) and the entanglement of the total system wave function that necessarily follows. The relevance of the present results to the einselection mechanism for decoherence, to the quantum measurement problem, and to the classical nature of the macroscopic world are discussed.
Supporting Kibble-Zurek Mechanism in Quantum Ising Model through a Trapped Ion
Jin-Ming Cui; Yun-Feng Huang; Zhao Wang; Dong-Yang Cao; Jian Wang; Wei-Min Lv; Yong Lu; Le Luo; Adolfo del Campo; Yong-Jian Han; Chuan-Feng Li; Guang-Can Guo
2015-05-21T23:59:59.000Z
Progress in quantum simulation has fostered the research on far-from-equilibrium dynamics. The Kibble-Zurek mechanism is the paradigmatic framework to account for the non adiabatic critical dynamics of a system driven across a phase transition in a finite time. Its study in the quantum regime is hindered by the requisite of ground state cooling. We report the experimental quantum simulation of critical dynamics in the transverse-field Ising model by a set of non-equilibrium processes in the pseudo-momentum space, that can be probed with high accuracy using a single trapped ion. Our results support the validity of the Kibble-Zurek mechanism in the quantum regime and advance the quantum simulation of critical systems far-away from equilibrium.
A Non-Local Reality: Is there a Phase Uncertainty in Quantum Mechanics?
Elizabeth S. Gould; Niayesh Afshordi
2014-07-15T23:59:59.000Z
A century after the advent of Quantum Mechanics and General Relativity, both theories enjoy incredible empirical success, constituting the cornerstones of modern physics. Yet, paradoxically, they suffer from deep-rooted, so-far intractable, conflicts. Motivations for violations of the notion of relativistic locality include the Bell's inequalities for hidden variable theories, the cosmological horizon problem, and Lorentz-violating approaches to quantum geometrodynamics, such as Horava-Lifshitz gravity. Here, we explore a recent proposal for a "real ensemble" non-local description of quantum mechanics, in which "particles" can copy each others' observable values AND phases, independent of their spatial separation. We first specify the exact theory, ensuring that it is consistent and has (ordinary) quantum mechanics as a fixed point, where all particles with the same values for a given observable have the same phases. We then study the stability of this fixed point numerically, and analytically, for simple models. We provide evidence that most systems (in our study) are locally stable to small deviations from quantum mechanics, and furthermore, the phase variance per value of the observable, as well as systematic deviations from quantum mechanics, decay as $\\sim$ (Energy$\\times$Time)$^{-2n}$, where $n \\geq 1$. Interestingly, this convergence is controlled by the absolute value of energy (and not energy difference), suggesting a possible connection to gravitational physics. Finally, we discuss different issues related to this theory, as well as potential novel applications for the spectrum of primordial cosmological perturbations and the cosmological constant problem.
Playing games in quantum mechanical settings: A necessary and sufficient condition
Junichi Shimamura; Sahin Kaya Ozdemir; Nobuyuki Imoto
2005-08-15T23:59:59.000Z
A number of recent studies have focused on novel features in game theory when the games are played using quantum mechanical toolbox (entanglement, unitary operators, measurement). Researchers have concentrated in two-player-two strategy, 2x2, dilemma containing classical games, and transferred them into quantum realm showing that in quantum pure strategies dilemmas in such games can be resolved if entanglement is distributed between the players armed with quantum operations. Moreover, it became clear that the players receive the highest sum of payoffs available in the game, which are otherwise impossible in classical pure strategies. Encouraged by the observation of rich dynamics of physical systems with many interacting parties and the power of entanglement in quantum versions of 2x2 games, it became generally accepted that quantum versions can be easily extended to N-player situations by simply allowing N-partite entangled states. In this article, however, we show that this is not generally true because the reproducibility of classical tasks in quantum domain imposes limitations on the type of entanglement and quantum operators. We propose a benchmark for the evaluation of quantum and classical versions of games, and derive the necessary and sufficient conditions for a physical realization. We give examples of entangled states that can and cannot be used, and the characteristics of quantum operators used as strategies.
Ulmer, W
2015-01-01T23:59:59.000Z
Friction incorporates the close connection between classical mechanics in irreversible thermodynamics. The translation to a quantum mechanical foundation is not trivial and requires a generalization of the Lagrange function. A change to electromagnetic circuits appears to more adequate, since the electric analogue (Ohms law) is related to scatter of electrons at lattice vibrations.
A note on the Landauer principle in quantum statistical mechanics
Vojkan Jaksic; Claude-Alain Pillet
2014-05-30T23:59:59.000Z
The Landauer principle asserts that the energy cost of erasure of one bit of information by the action of a thermal reservoir in equilibrium at temperature T is never less than $kTlog 2$. We discuss Landauer's principle for quantum statistical models describing a finite level quantum system S coupled to an infinitely extended thermal reservoir R. Using Araki's perturbation theory of KMS states and the Avron-Elgart adiabatic theorem we prove, under a natural ergodicity assumption on the joint system S+R, that Landauer's bound saturates for adiabatically switched interactions. The recent work of Reeb and Wolf on the subject is discussed and compared.
n the microcosmos of quantum mechanics, phenomena abound that
Nielsen, Steven O.
, can appear to behave as a water wave in one instance and as a discrete particle in another. Both. These waves interfere, producing a series of light and dark fringes when projected onto a screen [see point or another.) 86 SCIENTIFIC AMERICAN December 1994 The Duality in Matter and Light In quantum
States in the Hilbert space formulation and in the phase space formulation of quantum mechanics
Tosiek, J., E-mail: tosiek@p.lodz.pl; Brzykcy, P., E-mail: 800289@edu.p.lodz.pl
2013-05-15T23:59:59.000Z
We consider the problem of testing whether a given matrix in the Hilbert space formulation of quantum mechanics or a function considered in the phase space formulation of quantum theory represents a quantum state. We propose several practical criteria for recognising states in these two versions of quantum physics. After minor modifications, they can be applied to check positivity of any operators acting in a Hilbert space or positivity of any functions from an algebra with a ?-product of Weyl type. -- Highlights: ? Methods of testing whether a given matrix represents a quantum state. ? The Stratonovich–Weyl correspondence on an arbitrary symplectic manifold. ? Criteria for checking whether a function on a symplectic space is a Wigner function.
Cosmological Perturbations of Quantum-Mechanical Origin and Anisotropy of the Microwave Background
L. P. Grishchuk
1993-04-01T23:59:59.000Z
Cosmological perturbations generated quantum-mechanically (as a particular case, during inflation) possess statistical properties of squeezed quantum states. The power spectra of the perturbations are modulated and the angular distribution of the produced temperature fluctuations of the CMBR is quite specific. An exact formula is derived for the angular correlation function of the temperature fluctuations caused by squeezed gravitational waves. The predicted angular pattern can, in principle, be revealed by the COBE-type observations.
How to check quantum mechanics independently (Reply to arXiv:1505.04293)
Yuri I. Ozhigov
2015-06-17T23:59:59.000Z
This is the reply to the paper of Andrei Khrennikov arXiv:1505.04293 in which he expresses dissatisfaction with that the rough data in quantum experiments is not easily available and compares it with the open rough data in genetics. I try to explain why quantum experiments rough data is closed and why it differs radically from the biological. I also tried to answer the more thorny issue: is it possible to check quantum mechanics independently of other humans, e.g. trusting nobody.
Discrete Phase Space: Quantum mechanics and non-singular potential functions
Das, Anadijiban
2015-01-01T23:59:59.000Z
The three-dimensional potential equation, motivated by representations of quantum mechanics, is investigated in four different scenarios: (i) In the usual Euclidean space $\\mathbb{E}_{3}$ where the potential is singular but invariant under the continuous inhomogeneous orthogonal group $\\mathcal{I}O(3)$. The invariance under the translation subgroup is compared to the corresponding unitary transformation in the Schr\\"{o}dinger representation of quantum mechanics. This scenario is well known but serves as a reference point for the other scenarios. (ii) Next, the discrete potential equation as a partial difference equation in a three-dimensional lattice space is studied. In this arena the potential is non-singular but invariance under $\\mathcal{I}O(3)$ is broken. This is the usual picture of lattice theories and numerical approximations. (iii) Next we study the six-dimensional continuous phase space. Here a phase space representation of quantum mechanics is utilized. The resulting potential is singular but posse...
Testing Born's Rule in Quantum Mechanics with a Triple Slit Experiment
Urbasi Sinha; Christophe Couteau; Zachari Medendorp; Immo Söllner; Raymond Laflamme; Rafael Sorkin; Gregor Weihs
2008-11-13T23:59:59.000Z
In Mod. Phys. Lett. A 9, 3119 (1994), one of us (R.D.S) investigated a formulation of quantum mechanics as a generalized measure theory. Quantum mechanics computes probabilities from the absolute squares of complex amplitudes, and the resulting interference violates the (Kolmogorov) sum rule expressing the additivity of probabilities of mutually exclusive events. However, there is a higher order sum rule that quantum mechanics does obey, involving the probabilities of three mutually exclusive possibilities. We could imagine a yet more general theory by assuming that it violates the next higher sum rule. In this paper, we report results from an ongoing experiment that sets out to test the validity of this second sum rule by measuring the interference patterns produced by three slits and all the possible combinations of those slits being open or closed. We use attenuated laser light combined with single photon counting to confirm the particle character of the measured light.
On a Link between Classical Phenomenological Laws of Gases and Quantum Mechanics
Yarman, Tolga; Korfali, Onder
2008-01-01T23:59:59.000Z
In this paper we find a connection between the macroscopic classical laws of gases and the quantum mechanical description of molecules, composing an ideal gas. In such a gas, the motion of each individual molecule can be considered independently on all other molecules, and thus the macroscopic parameters of ideal gas, like pressure P and temperature T, can be introduced as a result of simple averaging over all individual motions of molecules. It is shown that for an ideal gas enclosed in a macroscopic cubic box of volume V, the constant, in the classical law of adiabatic expansion, i.e.PV^5/3=const, can be derived, based on quantum mechanics. Physical implications of the result we disclose are discussed. In any case, our finding proves, seemingly for the first time, a macroscopic manifestation of a quantum mechanical behavior, and this in relation to classical thermodynamics.
On a Link between Classical Phenomenological Laws of Gases and Quantum Mechanics
Tolga Yarman; Alexander Kholmetskii; Onder Korfali
2008-05-29T23:59:59.000Z
In this paper we find a connection between the macroscopic classical laws of gases and the quantum mechanical description of molecules, composing an ideal gas. In such a gas, the motion of each individual molecule can be considered independently on all other molecules, and thus the macroscopic parameters of ideal gas, like pressure P and temperature T, can be introduced as a result of simple averaging over all individual motions of molecules. It is shown that for an ideal gas enclosed in a macroscopic cubic box of volume V, the constant, in the classical law of adiabatic expansion, i.e.PV^5/3=const, can be derived, based on quantum mechanics. Physical implications of the result we disclose are discussed. In any case, our finding proves, seemingly for the first time, a macroscopic manifestation of a quantum mechanical behavior, and this in relation to classical thermodynamics.
Quantum Mechanical Corrections to Simulated Shock Hugoniot Temperatures
Goldman, N; Reed, E; Fried, L E
2009-07-17T23:59:59.000Z
The authors present a straightforward method for the inclusion of quantum nuclear vibrational effects in molecular dynamics calculations of shock Hugoniot temperatures. Using a grueneisen equation of state and a quasi-harmonic approximation to the vibrational energies, they derive a simple, post-processing method for calculation of the quantum corrected Hugoniot temperatures. They have used our novel technique on ab initio simulations of both shock compressed water and methane. Our results indicate significantly closer agreement with all available experimental temperature data for these two systems. Our formalism and technique can be easily applied to a number of different shock compressed molecular liquids or covalent solids, and has the potential to decrease the large uncertainties inherent in many experimental Hugoniot temperature measurements of these systems.
Fractal energy carpets in non-Hermitian Hofstadter quantum mechanics
Chernodub, M N
2015-01-01T23:59:59.000Z
We study the non-Hermitian Hofstadter dynamics of a quantum particle with biased motion on a square lattice in the background of a magnetic field. We show that in quasi-momentum space the energy spectrum is an overlap of infinitely many inequivalent fractals. The energy levels in each fractal are space-filling curves with Hausdorff dimension 2. The band structure of the spectrum is similar to a fractal spider net in contrast to the Hofstadter butterfly for unbiased motion.
Generalized contexts and consistent histories in quantum mechanics
Losada, Marcelo [Instituto de Física Rosario, Pellegrini 250, 2000 Rosario (Argentina); Laura, Roberto, E-mail: rlaura@fceia.unr.edu.ar [Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Pellegrini 250, 2000 Rosario (Argentina); Instituto de Física Rosario, Pellegrini 250, 2000 Rosario (Argentina)
2014-05-15T23:59:59.000Z
We analyze a restriction of the theory of consistent histories by imposing that a valid description of a physical system must include quantum histories which satisfy the consistency conditions for all states. We prove that these conditions are equivalent to imposing the compatibility conditions of our formalism of generalized contexts. Moreover, we show that the theory of consistent histories with the consistency conditions for all states and the formalism of generalized context are equally useful representing expressions which involve properties at different times.
R. Fedele; M. A. Man'ko; V. I. Man'ko; V. G. Vaccaro
2002-07-30T23:59:59.000Z
It is shown that the transmission line technology can be suitably used for simulating quantum mechanics. Using manageable and at the same time non-expensive technology, several quantum mechanical problems can be simulated for significant tutorial purposes. The electric signal envelope propagation through the line is governed by a Schrodinger-like equation for a complex function, representing the low-frequency component of the signal, In this preliminary analysis, we consider two classical examples, i.e. the Frank-Condon principle and the Ramsauer effect.
A closed formula for the barrier transmission coefficient in quaternionic quantum mechanics
De Leo, Stefano; Leonardi, Vinicius; Pereira, Kenia [Department of Applied Mathematics, State University of Campinas, SP 13083-970, Campinas (Brazil); Ducati, Gisele [CMCC, Federal University of ABC, SP 09210-170, Santo Andre (Brazil)
2010-11-15T23:59:59.000Z
In this paper, we analyze, by using a matrix approach, the dynamics of a nonrelativistic particle in presence of a quaternionic potential barrier. The matrix method used to solve the quaternionic Schroedinger equation allows us to obtain a closed formula for the transmission coefficient. Up to now, in quaternionic quantum mechanics, almost every discussion on the dynamics of nonrelativistic particle was motivated by or evolved from numerical studies. A closed formula for the transmission coefficient stimulates an analysis of qualitative differences between complex and quaternionic quantum mechanics and by using the stationary phase method, gives the possibility to discuss transmission times.
Miller, William H.
A novel discrete variable representation for quantum mechanical reactive scattering via the S. Phys. 88, 6233 ( 1988) ] for quantum reactive scattering. (It can also be readily used for quantum. INTRODUCTION The last three to four years have seen a "great leap for- ward" in the ability to carry out
Quantum Mechanics with a Momentum-Space Artificial Magnetic Field
Hannah M. Price; Tomoki Ozawa; Iacopo Carusotto
2014-11-19T23:59:59.000Z
The Berry curvature is a geometrical property of an energy band which acts as a momentum space magnetic field in the effective Hamiltonian describing single-particle quantum dynamics. We show how this perspective may be exploited to study systems directly relevant to ultracold gases and photonics. Given the exchanged roles of momentum and position, we demonstrate that the global topology of momentum space is crucially important. We propose an experiment to study the Harper-Hofstadter Hamiltonian with a harmonic trap that will illustrate the advantages of this approach and that will also constitute the first realization of magnetism on a torus.
Liu, Yong-Chun; Luan, Xingsheng; Wong, Chee Wei
2015-01-01T23:59:59.000Z
Ground state cooling of massive mechanical objects remains a difficult task restricted by the unresolved mechanical sidebands. We propose an optomechanically-induced-transparency cooling scheme to achieve ground state cooling of mechanical motion without the resolved sideband condition in a pure optomechanical system with two mechanical modes coupled to the same optical cavity mode. We show that ground state cooling is achievable for sideband resolution $\\omega_{m}/\\kappa$ as low as 0.003. This provides a new route for quantum manipulation of massive macroscopic devices and high-precision measurements.
The Radical Pair Mechanism and the Avian Chemical Compass: Quantum Coherence and Entanglement
Zhang, Yiteng; Kais, Sabre
2015-01-01T23:59:59.000Z
We review the spin radical pair mechanism which is a promising explanation of avian navigation. This mechanism is based on the dependence of product yields on (1) the hyperfine interaction involving electron spins and neighboring nuclear spins and (2) the intensity and orientation of the geomagnetic field. One surprising result is that even at ambient conditions quantum entanglement of electron spins can play an important role in avian magnetoreception. This review describes the general scheme of chemical reactions involving radical pairs generated from singlet and triplet precursors; the spin dynamics of the radical pairs; and the magnetic field dependence of product yields caused by the radical pair mechanism. The main part of the review includes a description of the chemical compass in birds. We review: the general properties of the avian compass; the basic scheme of the radical pair mechanism; the reaction kinetics in cryptochrome; quantum coherence and entanglement in the avian compass; and the effects o...
Chemical dynamics in the gas phase: Time-dependent quantum mechanics of chemical reactions
Gray, S.K. [Argonne National Laboratory, IL (United States)
1993-12-01T23:59:59.000Z
A major goal of this research is to obtain an understanding of the molecular reaction dynamics of three and four atom chemical reactions using numerically accurate quantum dynamics. This work involves: (i) the development and/or improvement of accurate quantum mechanical methods for the calculation and analysis of the properties of chemical reactions (e.g., rate constants and product distributions), and (ii) the determination of accurate dynamical results for selected chemical systems, which allow one to compare directly with experiment, determine the reliability of the underlying potential energy surfaces, and test the validity of approximate theories. This research emphasizes the use of recently developed time-dependent quantum mechanical methods, i.e. wave packet methods.
Branch dependence in the "consistent histories" approach to quantum mechanics
Thomas Müller
2006-11-12T23:59:59.000Z
In the consistent histories formalism one specifies a family of histories as an exhaustive set of pairwise exclusive descriptions of the dynamics of a quantum system. We define branching families of histories, which strike a middle ground between the two available mathematically precise definitions of families of histories, viz., product families and Isham's history projector operator formalism. The former are too narrow for applications, and the latter's generality comes at a certain cost, barring an intuitive reading of the ``histories''. Branching families retain the intuitiveness of product families, they allow for the interpretation of a history's weight as a probability, and they allow one to distinguish two kinds of coarse-graining, leading to reconsidering the motivation for the consistency condition.
Philosophy of mind and the problem of free will in the light of quantum mechanics
Henry P. Stapp
2008-05-01T23:59:59.000Z
Defects occasioned by the advent of quantum mechanics are described in detail of recent arguments by John Searle and by Jaegwon Kim pertaining to the question of the complete reducibility to the physical of the apparent capacity of a person's conscious thoughts to affect the behaviour of that person's physically described brain.
Goddard III, William A.
crossing in reactions still lags far behind. Theoretical approaches to extracting the underlying chemicalCorrelation Analysis of Chemical Bonds (CACB) II: Quantum Mechanical Operators for Classical of the statistical covariance of the previous operator. Here the bonds correlation relates to bond exchange processes
Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations
Liao, Rongzhen
Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations Rong hydratase is a tungsten-dependent enzyme that cata- lyzes the nonredox hydration of acetylene metalloenzyme cluster approach Tungsten is the heaviest metal in biology and plays prominent roles in carbon
Philosophy of Mind and the Problem of FreeWill in the Light of Quantum Mechanics.
Stapp, Henry; Stapp, Henry P
2008-04-01T23:59:59.000Z
Arguments pertaining to the mind-brain connection and to the physical effectiveness of our conscious choices have been presented in two recent books, one by John Searle, the other by Jaegwon Kim. These arguments are examined, and it is argued that the difficulties encountered arise from a defective understanding and application of a pertinent part of contemporary science, namely quantum mechanics.
Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V.; Pen'kov, N. V. [Voronezh State University (Russian Federation)
2006-08-15T23:59:59.000Z
In the framework of quantum-mechanical fission theory, the method of calculation for partial fission width amplitudes and asymptotic behavior of the fissile nucleus wave function with strong channel coupling taken into account has been suggested. The method allows one to solve the calculation problem of angular and energy distribution countation for binary and ternary fission.
WKB and MAF Quantization Rules for Spatially Confined Quantum Mechanical Systems
A. Sinha; R. Roychoudhury
1999-10-15T23:59:59.000Z
A formalism is developed to obtain the energy eigenvalues of spatially confined quantum mechanical systems in the framework of The usual WKB and MAF methods. The technique is applied to three different cases,viz one dimensional Harmonic Oscillators,Quartic Oscillators and a boxed-in charged particle in electric field.
Kauffman, Stuart
2014-01-01T23:59:59.000Z
I wish to discuss a large, interwoven set of topics pointed at in the title above. Much of what I say is highly speculative, some is testable, some is, at present, surely not. It is, I hope, useful, to set these ideas forth for our consideration. What I shall say assumes quantum measurement is real, and that Bohm's interpretation of Quantum Mechanics is not true. The Stalemate: In our contemporary neurobiology and much of the philosophy of mind post Descartes we are classical physics machines and either mindless, or mind is at best epiphenomenal and can have no consequences for the physical world. The first main point of this paper is that we are not forced to this conclusion, but must give up total reliance on classical physics.
Quantum mechanics in phase space: First order comparison between the Wigner and the Fermi function
G. Benenti; G. Strini
2009-09-08T23:59:59.000Z
The Fermi g_F(x,p) function provides a phase space description of quantum mechanics conceptually different from that based on the the Wigner function W(x,p). In this paper, we show that for a peaked wave packet the g_F(x,p)=0 curve approximately corresponds to a phase space contour level of the Wigner function and provides a satisfactory description of the wave packet's size and shape. Our results show that the Fermi function is an interesting tool to investigate quantum fluctuations in the semiclassical regime.
Graphs whose normalized Laplacian matrices are separable as density matrices in quantum mechanics
Chai Wah Wu
2014-07-23T23:59:59.000Z
Recently normalized Laplacian matrices of graphs are studied as density matrices in quantum mechanics. Separability and entanglement of density matrices are important properties as they determine the nonclassical behavior in quantum systems. In this note we look at the graphs whose normalized Laplacian matrices are separable or entangled. In particular, we show that the number of such graphs is related to the number of 0-1 matrices that are line sum symmetric and to the number of graphs with at least one vertex of degree 1.
The Radical Pair Mechanism and the Avian Chemical Compass: Quantum Coherence and Entanglement
Yiteng Zhang; Gennady P. Berman; Sabre Kais
2015-03-23T23:59:59.000Z
We review the spin radical pair mechanism which is a promising explanation of avian navigation. This mechanism is based on the dependence of product yields on (1) the hyperfine interaction involving electron spins and neighboring nuclear spins and (2) the intensity and orientation of the geomagnetic field. One surprising result is that even at ambient conditions quantum entanglement of electron spins can play an important role in avian magnetoreception. This review describes the general scheme of chemical reactions involving radical pairs generated from singlet and triplet precursors; the spin dynamics of the radical pairs; and the magnetic field dependence of product yields caused by the radical pair mechanism. The main part of the review includes a description of the chemical compass in birds. We review: the general properties of the avian compass; the basic scheme of the radical pair mechanism; the reaction kinetics in cryptochrome; quantum coherence and entanglement in the avian compass; and the effects of noise. We believe that the "quantum avian compass" can play an important role in avian navigation and can also provide the foundation for a new generation of sensitive and selective magnetic-sensing nano-devices.
Vacuum fluctuations the clue for a realistic interpretation of quantum mechanics
Emilio Santos
2012-08-22T23:59:59.000Z
Arguments are gived for the plausibility that quantum mechanics is a stochastic theory and that many quantum phenomena derive from the existence of a real noise consisting of vacuum fluctuations of all fundamental fields existing in nature. Planck's constant appears as the parameter fixing the scale of the fluctuations. Hints for an intuitive explanation are offered for some typical quantum features, like the uncertainty principle or the particle behaviour of fields. It is proposed that the recent discovery of dark energy in the universe is an argument for the reality of the vacuum fluctuations. A study is made of the compatibility of the model with the results of performed tests of Bell\\'{}s inequalities.
Orthogonal-state-based cryptography in quantum mechanics and local post-quantum theories
S. Aravinda; Anindita Banerjee; Anirban Pathak; R. Srikanth
2015-03-16T23:59:59.000Z
We introduce the concept of cryptographic reduction, in analogy with a similar concept in computational complexity theory. In this framework, class $A$ of crypto-protocols reduces to protocol class $B$ in a scenario $X$, if for every instance $a$ of $A$, there is an instance $b$ of $B$ and a secure transformation $X$ that reproduces $a$ given $b$, such that the security of $b$ guarantees the security of $a$. Here we employ this reductive framework to study the relationship between security in quantum key distribution (QKD) and quantum secure direct communication (QSDC). We show that replacing the streaming of independent qubits in a QKD scheme by block encoding and transmission (permuting the order of particles block by block) of qubits, we can construct a QSDC scheme. This forms the basis for the \\textit{block reduction} from a QSDC class of protocols to a QKD class of protocols, whereby if the latter is secure, then so is the former. Conversely, given a secure QSDC protocol, we can of course construct a secure QKD scheme by transmitting a random key as the direct message. Then the QKD class of protocols is secure, assuming the security of the QSDC class which it is built from. We refer to this method of deduction of security for this class of QKD protocols, as \\textit{key reduction}. Finally, we propose an orthogonal-state-based deterministic key distribution (KD) protocol which is secure in some local post-quantum theories. Its security arises neither from geographic splitting of a code state nor from Heisenberg uncertainty, but from post-measurement disturbance.
Process, System, Causality, and Quantum Mechanics, A Psychoanalysis of Animal Faith
H. Pierre Noyes; Tom Etter
1998-08-06T23:59:59.000Z
We shall argue in this paper that a central piece of modern physics does not really belong to physics at all but to elementary probability theory. Given a joint probability distribution J on a set of random variables containing x and y, define a link between x and y to be the condition x=y on J. Define the {\\it state} D of a link x=y as the joint probability distribution matrix on x and y without the link. The two core laws of quantum mechanics are the Born probability rule, and the unitary dynamical law whose best known form is the Schrodinger's equation. Von Neumann formulated these two laws in the language of Hilbert space as prob(P) = trace(PD) and D'T = TD respectively, where P is a projection, D and D' are (von Neumann) density matrices, and T is a unitary transformation. We'll see that if we regard link states as density matrices, the algebraic forms of these two core laws occur as completely general theorems about links. When we extend probability theory by allowing cases to count negatively, we find that the Hilbert space framework of quantum mechanics proper emerges from the assumption that all D's are symmetrical in rows and columns. On the other hand, Markovian systems emerge when we assume that one of every linked variable pair has a uniform probability distribution. By representing quantum and Markovian structure in this way, we see clearly both how they differ, and also how they can coexist in natural harmony with each other, as they must in quantum measurement, which we'll examine in some detail. Looking beyond quantum mechanics, we see how both structures have their special places in a much larger continuum of formal systems that we have yet to look for in nature.
Structure/Function Studies of Proteins Using Linear Scaling Quantum Mechanical Methodologies
Merz, K. M.
2004-07-19T23:59:59.000Z
We developed a linear-scaling semiempirical quantum mechanical (QM) program (DivCon). Using DivCon we can now routinely carry out calculations at the fully QM level on systems containing up to about 15 thousand atoms. We also implemented a Poisson-Boltzmann (PM) method into DivCon in order to compute solvation free energies and electrostatic properties of macromolecules in solution. This new suite of programs has allowed us to bring the power of quantum mechanics to bear on important biological problems associated with protein folding, drug design and enzyme catalysis. Hence, we have garnered insights into biological systems that have been heretofore impossible to obtain using classical simulation techniques.
Free-fall in a uniform gravitational field in non-commutative quantum mechanics
K. H. C. Castello-Branco; A. G. Martins
2011-05-23T23:59:59.000Z
We study the free-fall of a quantum particle in the context of noncommutative quantum mechanics (NCQM). Assuming noncommutativity of the canonical type between the coordinates of a two-dimensional configuration space, we consider a neutral particle trapped in a gravitational well and exactly solve the energy eigenvalue problem. By resorting to experimental data from the GRANIT experiment, in which the first energy levels of freely falling quantum ultracold neutrons were determined, we impose an upper-bound on the noncommutativity parameter. We also investigate the time of flight of a quantum particle moving in a uniform gravitational field in NCQM. This is related to the weak equivalence principle. As we consider stationary, energy eigenstates, i.e., delocalized states, the time of flight must be measured by a quantum clock, suitably coupled to the particle. By considering the clock as a small perturbation, we solve the (stationary) scattering problem associated and show that the time of flight is equal to the classical result, when the measurement is made far from the turning point. This result is interpreted as an extension of the equivalence principle to the realm of NCQM.
Free-fall in a uniform gravitational field in noncommutative quantum mechanics
Castello-Branco, K. H. C. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Sao-Carlense, 400, Sao Carlos, Sao Paulo 13560-970 (Brazil); Martins, A. G. [Departamento de Ciencias Naturais, Universidade do Estado do Para, Av. Djalma Dutra, s/n, Belem, Para 66113-200 (Brazil)
2010-10-15T23:59:59.000Z
We study the free-fall of a quantum particle in the context of noncommutative quantum mechanics (NCQM). Assuming noncommutativity of the canonical type between the coordinates of a two-dimensional configuration space, we consider a neutral particle trapped in a gravitational well and exactly solve the energy eigenvalue problem. By resorting to experimental data from the GRANIT experiment, in which the first energy levels of freely falling quantum ultracold neutrons were determined, we impose an upper-bound on the noncommutativity parameter. We also investigate the time of flight of a quantum particle moving in a uniform gravitational field in NCQM. This is related to the weak equivalence principle. As we consider stationary, energy eigenstates, i.e., delocalized states, the time of flight must be measured by a quantum clock, suitably coupled to the particle. By considering the clock as a small perturbation, we solve the (stationary) scattering problem associated and show that the time of flight is equal to the classical result, when the measurement is made far from the turning point. This result is interpreted as an extension of the equivalence principle to the realm of NCQM.
Classical limits of quantum mechanics on a non-commutative configuration space
Benatti, Fabio [Department of Physics, University of Trieste and INFN, Sezione di Trieste, Strada Costiera 11, I-34051 Trieste (Italy)] [Department of Physics, University of Trieste and INFN, Sezione di Trieste, Strada Costiera 11, I-34051 Trieste (Italy); Gouba, Laure [The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, I-34151 Trieste (Italy)] [The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, I-34151 Trieste (Italy)
2013-06-15T23:59:59.000Z
We consider a model of non-commutative quantum mechanics given by two harmonic oscillators over a non-commutative two dimensional configuration space. We study possible ways of removing the non-commutativity based on the classical limit context known as anti-Wick quantization. We show that removal of non-commutativity from the configuration space and from the canonical operators is not commuting operation.
M. Heller; W. Sasin
2000-01-24T23:59:59.000Z
The groupoid approach to noncommutative unification of general relativity with quantum mechanics is compared with the canonical gravity quantization. It is shown that by restricting the corresponding noncommutative algebra to its (commutative) subalgebra, which determines the space-time slicing, an algebraic counterpart of superspace (space of 3-metrics) can be obtained. It turns out that when this space-time slicing emerges the universe is already in its commutative regime. We explore the consequences of this result.
A quantum mechanical scheme to reduce radiation damage in electron microscopy
Okamoto, Hiroshi; Fink, Hans-Werner
2015-01-01T23:59:59.000Z
We show that radiation damage to unstained biological specimens is not an intractable problem in electron microscopy. When a structural hypothesis of a specimen is available, quantum mechanical principles allow us to verify the hypothesis with a very low electron dose. Realization of such a concept requires precise control of the electron wave front. Based on a diffractive electron optical implementation, we demonstrate the feasibility of this new method by both experimental and numerical investigations.
A quantum mechanical scheme to reduce radiation damage in electron microscopy
Hiroshi Okamoto; Tatiana Latychevskaia; Hans-Werner Fink
2015-06-24T23:59:59.000Z
We show that radiation damage to unstained biological specimens is not an intractable problem in electron microscopy. When a structural hypothesis of a specimen is available, quantum mechanical principles allow us to verify the hypothesis with a very low electron dose. Realization of such a concept requires precise control of the electron wave front. Based on a diffractive electron optical implementation, we demonstrate the feasibility of this new method by both experimental and numerical investigations.
Quantum corrected non-thermal radiation spectrum from the tunnelling mechanism
Subenoy Chakraborty; Subhajit Saha; Christian Corda
2015-05-28T23:59:59.000Z
Tunnelling mechanism is today considered a popular and widely used method in describing Hawking radiation. However, in relation to black hole (BH) emission, this mechanism is mostly used to obtain the Hawking temperature by comparing the probability of emission of an outgoing particle with the Boltzmann factor. On the other hand, Banerjee and Majhi reformulated the tunnelling framework deriving a black body spectrum through the density matrix for the outgoing modes for both the Bose-Einstein distribution and the Fermi-Dirac distribution. In contrast, Parikh and Wilczek introduced a correction term performing an exact calculation of the action for a tunnelling spherically symmetric particle and, as a result, the probability of emission of an outgoing particle corresponds to a non-strictly thermal radiation spectrum. Recently, one of us (C. Corda) introduced a BH effective state and was able to obtain a non-strictly black body spectrum from the tunnelling mechanism corresponding to the probability of emission of an outgoing particle found by Parikh and Wilczek. The present work introduces the quantum corrected effective temperature and the corresponding quantum corrected effective metric is written using Hawking's periodicity arguments. Thus, we obtain further corrections to the non-strictly thermal BH radiation spectrum as the final distributions take into account both the BH dynamical geometry during the emission of the particle and the quantum corrections to the semiclassical Hawking temperature.
An ultra-low dissipation micro-oscillator for quantum opto-mechanics
E. Serra; A. Borrielli; F. S. Cataliotti; F. Marin; F. Marino; A. Pontin; G. A. Prodi; M. Bonaldi
2012-08-30T23:59:59.000Z
Generating non-classical states of light by opto-mechanical coupling depends critically on the mechanical and optical properties of micro-oscillators and on the minimization of thermal noise. We present an oscillating micro-mirror with a mechanical quality factor Q = 2.6x10^6 at cryogenic temperature and a Finesse of 65000, obtained thanks to an innovative approach to the design and the control of mechanical dissipation. Already at 4 K with an input laser power of 2 mW, the radiation-pressure quantum fluctuations become the main noise source, overcoming thermal noise. This feature makes our devices particularly suitable for the production of pondero-motive squeezing.
Emission mechanisms of bulk GaN and InGaN quantum wells prepared by lateral epitaxial overgrowth
Bowers, John
Emission mechanisms of bulk GaN and InGaN quantum wells prepared by lateral epitaxial overgrowth S for publication 5 January 1999 The emission mechanisms of bulk GaN and InGaN quantum wells QWs were studied suggest that TDs simply reduce the net volume of light-emitting area. This effect is less pronounced in InGaN
Real-Time Transport in Open Quantum Systems From $\\mathcal{PT}$-Symmetric Quantum Mechanics
Justin E. Elenewski; Hanning Chen
2014-08-07T23:59:59.000Z
Nanoscale electronic transport is of intense technological interest, with applications ranging from semiconducting devices and molecular junctions to charge migration in biological systems. Most explicit theoretical approaches treat transport using a combination of density functional theory (DFT) and non-equilibrium Green's functions. This is a static formalism, with dynamic response properties accommodated only through complicated extensions. To circumvent this limitation, the carrier density may be propagated using real-time time-dependent DFT (RT-TDDFT), with boundary conditions corresponding to an open quantum system. Complex absorbing potentials can emulate outgoing particles at the simulation boundary, although these do not account for introduction of charge density. It is demonstrated that the desired positive particle flux is afforded by a class of $\\mathcal{PT}$-symmetric generating potentials that are characterized by anisotropic transmission resonances. These potentials add density every time a particle traverses the cell boundary, and may be used to engineer a continuous pulse train for incident packets. This is a first step toward developing a complete transport formalism unique to RT-TDDFT.
O. Arcizet; P. -F. Cohadon; T. Briant; M. Pinard; A. Heidmann; J. -M. Mackowski; C. Michel; L. Pinard; O. Francais; L. Rousseau
2006-05-19T23:59:59.000Z
We experimentally demonstrate the high-sensitivity optical monitoring of a micro-mechanical resonator and its cooling by active control. Coating a low-loss mirror upon the resonator, we have built an optomechanical sensor based on a very high-finesse cavity (30000). We have measured the thermal noise of the resonator with a quantum-limited sensitivity at the 10^-19 m/rootHz level, and cooled the resonator down to 5K by a cold-damping technique. Applications of our setup range from quantum optics experiments to the experimental demonstration of the quantum ground state of a macroscopic mechanical resonator.
Computer simulations of local anesthetic mechanisms: Quantum chemical investigation of procaine
Smith, Jeremy C [ORNL; Bondar, A.N. [University of California, Irvine; Suhai, Sandor [German Cancer Research Center, Heidelberg; Frangopol, P.T. [Institute of Atomic Physics, Bucharest Roumania
2007-02-01T23:59:59.000Z
A description at the atomic level of detail of the interaction between local anesthetics, lipid membranes and membrane proteins, is essential for understanding the mechanism of local anesthesia. The importance of performing computer simulations to decipher the mechanism of local anesthesia is discussed here in the context of the current status of understanding of the local anesthetics action. As a first step towards accurate simulations of the interaction between local anesthetics, proteins, lipid and water molecules, here we use quantum mechanical methods to assess the charge distribution and structural properties of procaine in the presence and in the absence of water molecules. The calculations indicate that, in the absence of hydrogen-bonding water molecules, protonated procaine strongly prefers a compact structure enabled by intramolecular hydrogen bonding. In the presence of water molecules the torsional energy pro?le of procaine is modified, and hydrogen bonding to water molecules is favored relative to intra-molecular hydrogen bonding.
Non-commutative Quantum Mechanics in Three Dimensions and Rotational Symmetry
Debabrata Sinha; Biswajit Chakraborty; Frederik G Scholtz
2011-08-12T23:59:59.000Z
We generalize the formulation of non-commutative quantum mechanics to three dimensional non-commutative space. Particular attention is paid to the identification of the quantum Hilbert space in which the physical states of the system are to be represented, the construction of the representation of the rotation group on this space, the deformation of the Leibnitz rule accompanying this representation and the implied necessity of deforming the co-product to restore the rotation symmetry automorphism. This also implies the breaking of rotational invariance on the level of the Schroedinger action and equation as well as the Hamiltonian, even for rotational invariant potentials. For rotational invariant potentials the symmetry breaking results purely from the deformation in the sense that the commutator of the Hamiltonian and angular momentum is proportional to the deformation.
Dinner, Aaron
Abstract. We present a method to treat the solvent ef- ficiently in hybrid quantum mechanical, the central reactive region is treated quan- tum mechanically to allow key bonds to be made and broken, while the surrounding non-reactive region is treated classically to make the calculations computa- tionally feasible
On the Irreps of the N-Extended Supersymmetric Quantum Mechanics and Their Fusion Graphs
Francesco Toppan
2006-12-27T23:59:59.000Z
In this talk we review the classification of the irreducible representations of the algebra of the N-extended one-dimensional supersymmetric quantum mechanics presented in hep-th/0511274. We answer some issues raised in hep-th/0611060, proving the agreement of the results here contained with those in hep-th/0511274. We further show that the fusion algebra of the 1D N-extended supersymmetric vacua introduced in hep-th/0511274 admits a graphical presentation. The N=2 graphs are here explicitly presented for the first time.
Quantum mechanics forbids an initial or final singularity in a closed FRW universe
T. R. Mongan
1999-03-07T23:59:59.000Z
The existence of singularities in a closed FRW universe depends on the assumption that general relativity is valid for distances less than the Planck length. However, stationary state wave functions of the Schrodinger equation for a closed radiation-dominated FRW universe derived by Elbaz et al (General Relativity and Gravitation 29, 481, 1997) are zero at zero radius of curvature. Thus, even if general relativity is assumed valid at distances less than the Planck length, quantum mechanics seems to forbid singularities in a closed FRW universe.
Sunandan Gangopadhyay; Anirban Saha; Swarup Saha
2014-09-11T23:59:59.000Z
The response of a test particle, both for the free case and under the harmonic oscillator potential, to circularly polarized gravitational waves is investigated in a noncommutative quantum mechanical setting. The system is quantized following the prescription in \\cite{ncgw1}. Standard algebraic techniques are then employed to solve the Hamiltonian of the system. The solutions, in both cases, show signatures of the coordinate noncommutativity. In the harmonic oscillator case, this signature plays a key role in altering the resonance point and the oscillation frequency of the system.
Phase Space Quantum Mechanics on the Anti-De Sitter Spacetime and its Poincaré Contraction
A. M. El Gradechi; S. De Bièvre
1992-10-26T23:59:59.000Z
In this work we propose an alternative description of the quantum mechanics of a massive and spinning free particle in anti-de~Sitter spacetime, using a phase space rather than a spacetime representation. The regularizing character of the curvature appears clearly in connection with a notion of localization in phase space which is shown to disappear in the zero curvature limit. We show in particular how the anti-de~Sitter optimally localized (coherent) states contract to plane waves as the curvature goes to zero. In the first part we give a detailed description of the classical theory {\\it \\a la Souriau\\/}. This serves as a basis for the quantum theory which is constructed in the second part using methods of geometric quantization. The invariant positive K\\"ahler polarization that selects the anti-de~Sitter quantum elementary system is shown to have as zero curvature limit the Poincar\\'e polarization which is no longer K\\"ahler. This phenomenon is then related to the disappearance of the notion of localization in the zero curvature limit.
Statistical mechanics of Coulomb gases as quantum theory on Riemann surfaces
Gulden, T.; Janas, M.; Koroteev, P.; Kamenev, A., E-mail: kamenev@physics.umn.edu [University of Minnesota, Department of Physics (United States)
2013-09-15T23:59:59.000Z
Statistical mechanics of a 1D multivalent Coulomb gas can be mapped onto non-Hermitian quantum mechanics. We use this example to develop the instanton calculus on Riemann surfaces. Borrowing from the formalism developed in the context of the Seiberg-Witten duality, we treat momentum and coordinate as complex variables. Constant-energy manifolds are given by Riemann surfaces of genus g {>=} 1. The actions along principal cycles on these surfaces obey the ordinary differential equation in the moduli space of the Riemann surface known as the Picard-Fuchs equation. We derive and solve the Picard-Fuchs equations for Coulomb gases of various charge content. Analysis of monodromies of these solutions around their singular points yields semiclassical spectra as well as instanton effects such as the Bloch bandwidth. Both are shown to be in perfect agreement with numerical simulations.
CM Rohwer; FG Scholtz
2012-06-06T23:59:59.000Z
In this thesis we shall demonstrate that a measurement of position alone in non-commutative space cannot yield complete information about the quantum state of a particle. Indeed, the formalism used entails a description that is non-local in that it requires all orders of positional derivatives through the star product that is used ubiquitously to map operator multiplication onto function multiplication in non-commutative systems. It will be shown that there exist several equivalent local descriptions, which are arrived at via the introduction of additional degrees of freedom. Consequently non-commutative quantum mechanical position measurements necessarily confront us with some additional structure which is necessary to specify quantum states completely. The remainder of the thesis, will involve investigations into the physical interpretation of these additional degrees of freedom. For one particular local formulation, the corresponding classical theory will be used to demonstrate that the concept of extended, structured objects emerges quite naturally and unavoidably there. This description will be shown to be equivalent to one describing a two-charge harmonically interacting composite in a strong magnetic field found by Susskind. It will be argued that these notions also extend naturally to the quantum level, and constraints will be shown to arise there. A further local formulation will be introduced, with an interpretation in terms of objects located at a point with a certain angular momentum about that point. This again enforces the idea of particles that are not point-like. Both local descriptions make explicit the additional structure which is encoded more subtly in the non-local description. Additional degrees of freedom introduced by local descriptions may also be thought of as gauge degrees of freedom in a gauge-invariant formulation of the theory.
Diederik Aerts; Massimiliano Sassoli de Bianchi
2015-04-19T23:59:59.000Z
The extended Bloch representation of quantum mechanics was recently derived to offer a (hidden-measurement) solution to the measurement problem. In this article we use it to investigate the geometry of superposition and entangled states, explaining the interference effects, and the entanglement correlations, in terms of the different orientations that a state-vector can take within the generalized Bloch sphere. We also introduce a tensorial determination of the generators of SU(N), particularly suitable to describe multipartite systems, from the viewpoint of the sub-entities. We then use it to show that non-product states admit a general description in which the sub-entities can always remain in well-defined states, even when they are entangled. Therefore, the completed version of quantum mechanics provided by the extended Bloch representation, in which the density operators are also representative of pure states, allows to solve not only the well-known measurement problem, but also the lesser-known entanglement problem. This because we no longer need to give up the general physical principle saying that a composite entity exists, and therefore is in a pure state, if and only if its components also exist, and therefore are in well-defined pure states.
Vacuum Fluctuation (1): the Same Basis of the Relativity and the Quantum Mechanics
Xing-Hao Ye
2007-11-09T23:59:59.000Z
The aim of this paper is to reveal the deep relationship between matter and vacuum, and to seek for the same physical basis of the relativity and the quantum mechanics. In doing this, three postulates of vacuum fluctuation are proposed first, the basic premises of the relativity and the quantum mechanics including the velocity limit, the energy-frequency relation and the de Broglie wavelength expression of any matter particles are deduced then. As applications, the idea is used to analyze the Compton effect and the electron-positron annihilation. It is found that the calculation becomes simple, and the physical meaning gets clear. The simplicity comes from the power of the three postulates. To illustrate this, the basic conclusions of the special theory of relativity such as the relations of mass-velocity, mass-energy, energy-momentum, time dilation and length contraction are further deduced. In addition, the significance of the investigation of vacuum fluctuation in the unification of the physical theories is pointed out.
Spin Matrix Theory: A quantum mechanical model of the AdS/CFT correspondence
Troels Harmark; Marta Orselli
2014-10-31T23:59:59.000Z
We introduce a new quantum mechanical theory called Spin Matrix theory (SMT). The theory is interacting with a single coupling constant g and is based on a Hilbert space of harmonic oscillators with a spin index taking values in a Lie (super)algebra representation as well as matrix indices for the adjoint representation of U(N). We show that SMT describes N=4 super-Yang-Mills theory (SYM) near zero-temperature critical points in the grand canonical phase diagram. Equivalently, SMT arises from non-relativistic limits of N=4 SYM. Even though SMT is a non-relativistic quantum mechanical theory it contains a variety of phases mimicking the AdS/CFT correspondence. Moreover, the infinite g limit of SMT can be mapped to the supersymmetric sector of string theory on AdS_5 x S^5. We study SU(2) SMT in detail. At large N and low temperatures it is a theory of spin chains that for small g resembles planar gauge theory and for large g a non-relativistic string theory. When raising the temperature a partial deconfinement transition occurs due to finite-N effects. For sufficiently high temperatures the partially deconfined phase has a classical regime. We find a matrix model description of this regime at any coupling g. Setting g=0 it is a theory of N^2+1 harmonic oscillators while for large g it becomes 2N harmonic oscillators.
Quantum mechanical approaches to in silico enzyme characterization and drug design
Nilmeier, J P; Fattebert, J L; Jacobson, M P; Kalyanaraman, C
2012-01-17T23:59:59.000Z
The astonishing, exponentially increasing rates of genome sequencing has led to one of the most significant challenges for the biological and computational sciences in the 21st century: assigning the likely functions of the encoded proteins. Enzymes represent a particular challenge, and a critical one, because the universe of enzymes is likely to contain many novel functions that may be useful for synthetic biology, or as drug targets. Current approaches to protein annotation are largely based on bioinformatics. At the simplest level, this annotation involves transferring the annotations of characterized enzymes to related sequences. In practice, however, there is no simple, sequence based criterion for transferring annotations, and bioinformatics alone cannot propose new enzymatic functions. Structure-based computational methods have the potential to address these limitations, by identifying potential substrates of enzymes, as we and others have shown. One successful approach has used in silico 'docking' methods, more commonly applied in structure-based drug design, to identify possible metabolite substrates. A major limitation of this approach is that it only considers substrate binding, and does not directly assess the potential of the enzyme to catalyze a particular reaction using a particular substrate. That is, substrate binding affinity is necessary but not sufficient to assign function. A reaction profile is ultimately what is needed for a more complete quantitative description of function. To address this rather fundamental limitation, they propose to use quantum mechanical methods to explicitly compute transition state barriers that govern the rates of catalysis. Although quantum mechanical, and mixed quantum/classical (QM/MM), methods have been used extensively to investigate enzymatic reactions, the focus has been primarily on elucidating complex reaction mechanisms. Here, the key catalytic steps are known, and they use these methods quantify substrate specificity. That is, we bring the power of quantum mechanics to bear on the problem of annotating enzyme function, which is a novel approach. Although it has been clear to us at the Jacobson group for some time that enzyme specificity may be encoded in transition states, rather than simply substrate recognition, the main limitation has always been computational expense. Using a hierarchy of different methods, they can reduce the list of plausible substrates of an enzyme to a small number in most cases, but even identifying the transition states for a dozen plausible substrates requires significant computational effort, beyond what is practical using standard QM/MM methods. For this project, they have chosen two enzyme superfamilies which they have used as 'model systems' for functional assignment. The enolase superfamily is a large group of {alpha}-{beta} barrel enzymes with highly diverse substrates and chemical transformations. Despite decades of work, over a third of the superfamily remains unassigned, which means that the remaining cases are by definition difficult to assign. They have focused on acid sugar dehydratases, and have considerable expertise on the matter. They are also interested in the isoprenoid synthase superfamily, which is of central interest to the synthetic biology community, because these enzymes are used by nature to create complex rare natural products of medicinal value. the most notable example of this is the artemisinin, an antimalarial compound that is found in trace amounts in the wormwod root. From the standpoint of enzyme function assignment, these enzymes are intriguing because they use a small number of chemically simple substrates to generate, potentially, tens of thousands of different products. Hence, substrate binding specificity is only a small part of the challenge; the key is determining how the enzyme directs the carbocation chemistry to specific products. These more complex modeling approaches clearly require quantum mechanical methods.
Molecular Quantum Mechanics 2010: From Methylene to DNA and Beyond Conference Support
None
2013-05-15T23:59:59.000Z
This grant was $12500 for partial support of an international conference, Molecular Quantum Mechanics 2010, which was held on the campus of the University of California, Berkeley, from 24 to 29 May 2010. The conference involved more than 250 participants. The conference schedule ran from as early as 8:00 AM to as late as 10:30 PM at night, in order to accommodate six historical lectures, 16 plenary lectures, 42 invited talks and two very strong poster sessions containing 143 contributed posters. Since 1989, the Molecular Quantum Mechanics (MQM) series of international conferences has show- cased the frontiers of research in quantum chemistry with a strong focus on basic theory and algorithms, as well as highlights of topical applications. Both were strongly in evidence at MQM 2010. At the same time as embracing the future, the MQM conferences also honour the lifetime contributions of some of the most prominent scientists in the field of theoretical and computational quantum chemistry. MQM 2010 recognised the work of Prof. Henry F. ‘Fritz’ Schaefer of the Center for Computational Chemistry at the University of Georgia, who was previously on the faculty at Berkeley The travel of invited speakers was partially covered by sponsorships from Dell Computer, Hewlett-Packard, Journal of Chemical Theory and Computation, Virginia Tech College of Science, Molecular Physics, Q-Chem Inc and the American Institute of Physics. By contrast, the conference grant from the Department of Energy was used to provide fellowships and scholarships to enable graduate students and postdoctoral fellows to attend the meeting, and thereby broaden the participation of young scientists at a meeting where in the past most of the attendees have been more senior faculty researchers. We believe that we were very successful in this regard: 118 students and postdocs attended out of the total of 256 participants. In detail, the DOE sponsorship money was partially used for dormitory scholarships that covered the cost of shared accommodation for students and postdocs at Berkeley dormitories. This covered the $200-$305 cost of a shared room for the 5-day duration of the conference. The only condition of these scholarships was that the awardee must present a poster at the meeting. Approximately $7565 was spent for these dormitory scholarships. The remaining expenditures of $4800 was used for 12 merit scholarships which were awarded to students whose poster presentations were judged the best at the conference. This amount covered a significant part of their travel and registration fees.
Cosmology with a Decaying Vacuum Energy Parametrization Derived from Quantum Mechanics
Szydlowski, Marek; Urbanowski, Krzysztof
2015-01-01T23:59:59.000Z
Within the quantum mechanical treatment of the decay problem one finds that at late times $t$ the survival probability of an unstable state cannot have the form of an exponentially decreasing function of time $t$ but it has an inverse power-like form. This is a general property of unstable states following from basic principles of quantum theory. The consequence of this property is that in the case of false vacuum states the cosmological constant becomes dependent on time: $\\Lambda - \\Lambda_{\\text{bare}}\\equiv \\Lambda(t) -\\Lambda_{\\text{bare}} \\sim 1/t^{2}$. We construct the cosmological model with decaying vacuum energy density and matter for solving the cosmological constant problem and the coincidence problem. We show the equivalence of the proposed decaying false vacuum cosmology with the $\\Lambda(t)$ cosmologies (the $\\Lambda(t)$CDM models). The cosmological implications of the model of decaying vacuum energy (dark energy) are discussed. We constrain the parameters of the model with decaying vacuum usin...
Numerical investigations of Supersymmetric Yang-Mills Quantum Mechanics with 4 supercharges
Zbigniew Ambrozinski; Piotr Korcyl
2014-12-01T23:59:59.000Z
We report on our non-perturbative investigations of supersymmetric Yang-Mills quantum mechanics with 4 supercharges. We employ two independent numerical methods. First of them is the cut Fock space method whose numerical implementation was recently generalized to include the SU(N) gauge group. It allowed us to calculate for the first time the spectrum of the model with SU(3) symmetry in all fermionic sectors. Independently, we implemented the Rational Hybrid Monte Carlo algorithm and reproduced the accessible part of the low-energy spectrum of the model with SU(2) gauge symmetry. We argue that by simulating at imaginary chemical potential one can get access to observables defined in sectors of Hilbert space with a given quark number.
Lee, Chien-Wei; Hwu, Jenn-Gwo [Graduate Institute of Electronics Engineering/ Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)] [Graduate Institute of Electronics Engineering/ Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)
2013-10-15T23:59:59.000Z
We derive a statistical physics model of two-dimensional electron gas (2DEG) and propose an accurate approximation method for calculating the quantum-mechanical effects of metal-oxide-semiconductor (MOS) structure in accumulation and strong inversion regions. We use an exponential surface potential approximation in solving the quantization energy levels and derive the function of density of states in 2D to 3D transition region by applying uncertainty principle and Schrödinger equation in k-space. The simulation results show that our approximation method and theory of density of states solve the two major problems of previous researches: the non-negligible error caused by the linear potential approximation and the inconsistency of density of states and carrier distribution in 2D to 3D transition region.
Benioff, P.A.
1981-01-01T23:59:59.000Z
Work done before on the construction of quantum mechanical Hamiltonian models of Turing machines and general descrete processes is extended here to include processes which erase their own histories. The models consist of three phases, the forward process phase in which a map T is iterated and a history of iterations is generated, a copy phase which is activated if and only if T reaches a fix point, and an erase phase which erases the iteration history, undoes the iterations of T and recovers the initial state except for the copy system. A ballast system is used to stop the evolution at the desired state. The general model so constructed is applied to Turing machines. The main changes are that the system undergoing the evolution corresponding to T iterations becomes three systems corresponding to the internal machine, the computation tape, and computation head. Also the copy phase becomes more complex since it is desired that this correspond also to a copying Turing machine.
Orbital HP-Clouds for Solving Schr?dinger Equation inQuantum Mechanics
Chen, J; Hu, W; Puso, M
2006-10-19T23:59:59.000Z
Solving Schroedinger equation in quantum mechanics presents a challenging task in numerical methods due to the high order behavior and high dimension characteristics in the wave functions, in addition to the highly coupled nature between wave functions. This work introduces orbital and polynomial enrichment functions to the partition of unity for solution of Schroedinger equation under the framework of HP-Clouds. An intrinsic enrichment of orbital function and extrinsic enrichment of monomial functions are proposed. Due to the employment of higher order basis functions, a higher order stabilized conforming nodal integration is developed. The proposed methods are implemented using the density functional theory for solution of Schroedinger equation. Analysis of several single and multi-electron/nucleus structures demonstrates the effectiveness of the proposed method.
Natural star-products on symplectic manifolds and related quantum mechanical operators
B?aszak, Maciej, E-mail: blaszakm@amu.edu.pl; Doma?ski, Ziemowit, E-mail: ziemowit@amu.edu.pl
2014-05-15T23:59:59.000Z
In this paper is considered a problem of defining natural star-products on symplectic manifolds, admissible for quantization of classical Hamiltonian systems. First, a construction of a star-product on a cotangent bundle to an Euclidean configuration space is given with the use of a sequence of pair-wise commuting vector fields. The connection with a covariant representation of such a star-product is also presented. Then, an extension of the construction to symplectic manifolds over flat and non-flat pseudo-Riemannian configuration spaces is discussed. Finally, a coordinate free construction of related quantum mechanical operators from Hilbert space over respective configuration space is presented. -- Highlights: •Invariant representations of natural star-products on symplectic manifolds are considered. •Star-products induced by flat and non-flat connections are investigated. •Operator representations in Hilbert space of considered star-algebras are constructed.
A quantum mechanical model for the relationship between stock price and stock ownership
Liviu-Adrian Cotfas
2012-09-05T23:59:59.000Z
The trade of a fixed stock can be regarded as the basic process that measures its momentary price. The stock price is exactly known only at the time of sale when the stock is between traders, that is, only in the case when the owner is unknown. We show that the stock price can be better described by a function indicating at any moment of time the probabilities for the possible values of price if a transaction takes place. This more general description contains partial information on the stock price, but it also contains partial information on the stock owner. By following the analogy with quantum mechanics, we assume that the time evolution of the function describing the stock price can be described by a Schrodinger type equation.
A quantitative quantum-chemical analysis tool for the distribution of mechanical force in molecules
Stauch, Tim; Dreuw, Andreas, E-mail: dreuw@uni-heidelberg.de [Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany)] [Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany)
2014-04-07T23:59:59.000Z
The promising field of mechanochemistry suffers from a general lack of understanding of the distribution and propagation of force in a stretched molecule, which limits its applicability up to the present day. In this article, we introduce the JEDI (Judgement of Energy DIstribution) analysis, which is the first quantum chemical method that provides a quantitative understanding of the distribution of mechanical stress energy among all degrees of freedom in a molecule. The method is carried out on the basis of static or dynamic calculations under the influence of an external force and makes use of a Hessian matrix in redundant internal coordinates (bond lengths, bond angles, and dihedral angles), so that all relevant degrees of freedom of a molecule are included and mechanochemical processes can be interpreted in a chemically intuitive way. The JEDI method is characterized by its modest computational effort, with the calculation of the Hessian being the rate-determining step, and delivers, except for the harmonic approximation, exact ab initio results. We apply the JEDI analysis to several example molecules in both static quantum chemical calculations and Born-Oppenheimer Molecular Dynamics simulations in which molecules are subject to an external force, thus studying not only the distribution and the propagation of strain in mechanically deformed systems, but also gaining valuable insights into the mechanochemically induced isomerization of trans-3,4-dimethylcyclobutene to trans,trans-2,4-hexadiene. The JEDI analysis can potentially be used in the discussion of sonochemical reactions, molecular motors, mechanophores, and photoswitches as well as in the development of molecular force probes.
Novel photonic bandgap based architectures for quantum computers and networks
Güney, Durdu
2007-01-01T23:59:59.000Z
microcontrollers (MC), microelectromechanical systems (MEMS)block. A microelectromechanical systems (MEMS) actuator,such as microelectromechanical systems (MEMS), quantum dots,
Mar 2, 2004 ... McMaster University. Advanced Optimization Laboratory ...... library for convex optimization based on an analytic center cutting plane method,.
D. B. (Ben) McReynolds. Purdue University, Department of Mathematics. 150 S. University, Math 704,. dmcreyno at math dot purdue dot edu. New main ...
Xi Kong; Mingjun Shi; Fazhan Shi; Pengfei Wang; Pu Huang; Qi Zhang; Chenyong Ju; Changkui Duan; Sixia Yu; Jiangfeng Du
2012-10-03T23:59:59.000Z
Quantum mechanics provides a statistical description about nature, and thus would be incomplete if its statistical predictions could not be accounted for by some realistic models with hidden variables. There are, however, two powerful theorems against the hidden-variable theories showing that certain quantum features cannot be reproduced based on two rationale premises of locality, Bell's theorem, and noncontextuality, due to Bell, Kochen and Specker (BKS). Noncontextuality is independent of nonlocality, and the contextuality manifests itself even in a single object. Here we report an experimental verification of quantum contextuality by a single spin-1 electron system at room temperature. Such a three-level system is indivisible and then we close the compatibility loophole which exists in the experiments performed on bipartite systems. Our results confirm the quantum contextuality to be the intrinsic property of single particles.
Goddard III, William A.
resistance of "end-contacted" metal electrode-graphene and metal electrode-carbon nanotube (CNT) interfaces for five metals, Ti, Pd, Pt, Cu, and Au, based on the first-principles quantum mechanical (QM) density atoms) is 107 k for Ti, 142 k for Pd, 149 k for Pt, 253 k for Cu, and 187 k for Au. This can be compared
Simons, Jack
Quantum Mechanical Energy-Based Screening of Combinatorially Generated Library of Tautomers. Tau of GdanÂ´sk, 80-952 GdanÂ´sk, Poland, Chemical Sciences Division, Fundamental Sciences Directorate, Pacific of finding low-energy tautomers of a molecule. The procedure consists of (i) combinatorial generation
Calculation of the electron two slit experiment using a quantum mechanical variational principle
Harrison, Alan K. [Los Alamos National Laboratory
2012-04-17T23:59:59.000Z
A nonlocal relativistic variational principle (VP) has recently been proposed as an alternative to the Dirac wave equation of standard quantum mechanics. We apply that principle to the electron two-slit experiment. The detection system is modelled as a screen made of atoms, any one of which can be excited by the incident electron, but we avoid restricting the detection mechanism further. The VP is shown to predict that, at the time the electron reaches the screen, its wavefunction will be localized to the neighborhood of a single atom, resulting in a position-type measurement. In an ensemble of such experiments ('identically prepared' except that the initial phase of the wavefunction - the hidden variable in the VP formulation - is sampled over the expected uniform distribution), the distribution of measured positions will reproduce the interference pattern predicted by the Dirac equation. We also demonstrate that with a detection system designed fundamentally to detect the electron's transverse wavelength rather than its position, the VP predicts that one such mode will be detected, that is, a wavelength measurement will result. Finally, it is shown that these results are unchanged in the 'delayed choice' variant of the experiment.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from a NewCuneo Matthew1, 2012 1:00McPhD McPhD McPhD is
Karl Svozil
2001-06-29T23:59:59.000Z
Three extensions and reinterpretations of nonclassical probabilities are reviewed. (i) We propose to generalize the probability axiom of quantum mechanics to self-adjoint positive operators of trace one. Furthermore, we discuss the Cartesian and polar decomposition of arbitrary normal operators and the possibility to operationalize the corresponding observables. Thereby we review and emphasize the use of observables which maximally represent the context. (ii) In the second part, we discuss Pitowsky polytopes for automaton logic as well as for generalized urn models and evaluate methods to find the resulting Boole-Bell type (in)equalities. (iii) Finally, so-called ``parameter cheats'' are introduced, whereby parameters are transformed bijectively and nonlinearly in such a way that classical systems mimic quantum correlations and vice versa. It is even possible to introduce parameter cheats which violate the Boole-Bell type inequalities stronger than quantum ones, thereby trespassing the Tsirelson limit. The price to be paid is nonuniformity.
Non-Geometric Fluxes, Quasi-Hopf Twist Deformations and Nonassociative Quantum Mechanics
Dionysios Mylonas; Peter Schupp; Richard J. Szabo
2014-10-24T23:59:59.000Z
We analyse the symmetries underlying nonassociative deformations of geometry in non-geometric R-flux compactifications which arise via T-duality from closed strings with constant geometric fluxes. Starting from the non-abelian Lie algebra of translations and Bopp shifts in phase space, together with a suitable cochain twist, we construct the quasi-Hopf algebra of symmetries that deforms the algebra of functions and the exterior differential calculus in the phase space description of nonassociative R-space. In this setting nonassociativity is characterised by the associator 3-cocycle which controls non-coassociativity of the quasi-Hopf algebra. We use abelian 2-cocycle twists to construct maps between the dynamical nonassociative star product and a family of associative star products parametrized by constant momentum surfaces in phase space. We define a suitable integration on these nonassociative spaces and find that the usual cyclicity of associative noncommutative deformations is replaced by weaker notions of 2-cyclicity and 3-cyclicity. Using this star product quantization on phase space together with 3-cyclicity, we formulate a consistent version of nonassociative quantum mechanics, in which we calculate the expectation values of area and volume operators, and find coarse-graining of the string background due to the R-flux.
Quantum-mechanical nonequivalence of metrics of centrally symmetric uncharged gravitational field
M. V. Gorbatenko; V. P. Neznamov
2013-08-02T23:59:59.000Z
Quantum-mechanical analysis shows that the metrics of a centrally symmetric uncharged gravitational field, which are exact solutions of the general relativity equations, are physically non-equivalent. The classical Schwarzschield metric and the Schwarzschild metrics in isotropic and harmonic coordinates provide for the existence of stationary bound states of Dirac particles with a real energy spectrum. The Hilbert condition g_{00}>0 is responsible for zero values of the wave functions under the "event horizon" that leads to the absence of Hawking radiation. For the Eddington-Finkelstein and Painleve-Gullstrand metrics, stationary bound states of spin-half particles cannot exist because Dirac Hamiltonians are non-Hermitian. For these metrics, the condition g_{00}>0 also leads to the absence of Hawking evaporation. For the Finkelstein-Lemaitre and Kruskal metrics, Dirac Hamiltonians are explicitly time-dependent, and stationary bound states of spin-half particles cannot exist for them. The Hilbert condition for these metrics does not place any constraints on the domains of the wave functions. Hawking evaporation of black holes is possible in this case. The results can lead to revisiting some concepts of the standard cosmological model related to the evolution of the universe and interaction of collapsars with surrounding matter.
Richards-Kortum, Rebecca
204 Mechanical Engineering and Materials Science 205 of Architecture. The campus-wide Rice Quantum. Degree Requirements for B.A., B.S.M.E. in Mechanical Engineering or B.A., B.S.M.S. in Materials Science and Engineering The B.A. program in either mechanical engineering or materials science
Elio Conte; Andrei Yuri Khrennikov; Orlando Todarello; Antonio Federici; Joseph P. Zbilut
2008-04-10T23:59:59.000Z
In the first part of the paper we reach an experimental final confirmation that mental states follow quantum mechanics. In the second part further experimentation indicates that in mind states Bell inequality violation is possible.
Le Roy, Robert J.
February 1998 Comparisons of classical and quantum Monte Carlo simulation of SF6 Ar n and SF6 Ne n clusters are used to examine whether certain novel types of behavior seen in classical simulations of SF6 Ar n and SF6 Kr n persist when quantum effects are taken into account. For mixed clusters formed
Wave-Particle Duality Revitalized: Consequences, Applications and Relativistic Quantum Mechanics
Himanshu Chauhan; Swati Rawal; R. K. Sinha
2011-10-19T23:59:59.000Z
The proposed paper presents the unobserved inadequacies in de Broglie's concepts of wave-particle duality and matter waves in the year 1923. The commonly admitted quantum energy or frequency expression h{\
Efficiency loss mechanisms in colloidal quantum-dot light-emitting diodes
Shirasaki, Yasuhiro
2013-01-01T23:59:59.000Z
Saturated and tunable emission colors make colloidal quantum-dot light-emitting diodes (QD-LEDs) interesting for the next generation of display and lighting technologies. However, there still remain various hurdles to the ...
Entropic Dynamics: from Entropy and Information Geometry to Hamiltonians and Quantum Mechanics
Ariel Caticha; Daniel Bartolomeo; Marcel Reginatto
2014-12-17T23:59:59.000Z
Entropic Dynamics is a framework in which quantum theory is derived as an application of entropic methods of inference. There is no underlying action principle. Instead, the dynamics is driven by entropy subject to the appropriate constraints. In this paper we show how a Hamiltonian dynamics arises as a type of non-dissipative entropic dynamics. We also show that the particular form of the "quantum potential" that leads to the Schroedinger equation follows naturally from information geometry.
Simulation of quantum-mechanical supersymmetry in a Cooper-pair box shunted by a Josephson rhombus
Jascha Ulrich; Daniel Otten; Fabian Hassler
2015-03-13T23:59:59.000Z
Supersymmetries in quantum mechanics offer a way to obtain degeneracies in the excitation spectrum which do not originate from selection rules. The mechanism behind the degeneracies is the same as the one that leads to the miraculous cancellations of divergences in supersymmetric field theories found in the high energy physics context. Even though of importance, there is up to now no realistic proposal of non-integrable systems that show level degeneracies due to a supersymmetric structure. Here, we propose an implementation of a quantum-mechanical supersymmetry in a Cooper-pair box shunted by a Josephson junction rhombus which is effectively $\\pi$-periodic in the superconducting phase difference. For a characteristic ratio between the strength of the $2\\pi$- and the $\\pi$-periodic junction, we find a two-fold degeneracy of all the energy levels all the way from the weak junction/charge qubit limit to the strong junction/transmon regime. We provide explicit values for the parameters of the rhombus and show that tuning in and out of the supersymmetric point is easily achieved by varying an external gate voltage. We furthermore discuss a microwave experiment to detect the supersymmetry and conclude that it could indeed be simulated with currently existing Josephson junction technology.
Broader source: Energy.gov [DOE]
Tom McQuiston is a doctor of public health specializing in occupational health, safety and environment issues.
Gräter, Frauke
Protein/Ligand Binding Free Energies Calculated with Quantum Mechanics/Molecular Mechanics Frauke of the complexes are predicted (the "docking" problem) as well as in how the free energy is calculated from)solvation during the binding process.3 Typically, binding free energies calculated with these methods have average
Ronnie Kosloff
2013-05-10T23:59:59.000Z
Quantum thermodynamics addresses the emergence of thermodynamical laws from quantum mechanics. The link is based on the intimate connection of quantum thermodynamics with the theory of open quantum systems. Quantum mechanics inserts dynamics into thermodynamics giving a sound foundation to finite-time-thermodynamics. The emergence of the 0-law I-law II-law and III-law of thermodynamics from quantum considerations is presented. The emphasis is on consistence between the two theories which address the same subject from different foundations. We claim that inconsistency is the result of faulty analysis pointing to flaws in approximations.
Quantum robots and quantum computers
Benioff, P.
1998-07-01T23:59:59.000Z
Validation of a presumably universal theory, such as quantum mechanics, requires a quantum mechanical description of systems that carry out theoretical calculations and systems that carry out experiments. The description of quantum computers is under active development. No description of systems to carry out experiments has been given. A small step in this direction is taken here by giving a description of quantum robots as mobile systems with on board quantum computers that interact with different environments. Some properties of these systems are discussed. A specific model based on the literature descriptions of quantum Turing machines is presented.
X. Q. Huang
2006-04-04T23:59:59.000Z
We study the energy conversion laws of the macroscopic harmonic $LC $ oscillator, the electromagnetic wave (photon) and the hydrogen atom. As our analysis indicates that the energies of these apparently different systems obey exactly the same energy conversion law. Based on our results and the wave-particle duality of electron, we find that the atom in fact is a natural microscopic $LC$ oscillator. In the framework of classical electromagnetic field theory we analytically obtain, for the hydrogen atom, the quantized electron orbit radius. Without the adaptation of any other fundamental principles of quantum mechanics, we present a reasonable explanation of the polarization of photon, the Zeeman effect, Selection rules and Pauli exclusion principle. Particularly, it is found that a pairing Pauli electron can move closely and steadily in a DNA-like double helical electron orbit. Our results also reveal an essential connection between electron spin and the intrinsic helical movement of electron and indicate that the spin itself is the effect of quantum confinement. In addition, a possible physical mechanism of superconductivity and the deeper physical understandings of the electron mass, zero point energy, and the hardness property of electron are also provided. Finally, we show analytically that the Dirac's quantization of magnetic monopole is merely a special handed electron at absolute zero-temperature, which strongly suggests that any efforts to seek for the magneticmonopole in real space will be entirely in vain. Furthermore, it appears that the electron's spin and the magnetic monopole are actually two different concepts for one possible physical phenomenon.
Ford, Arlene C.
2011-08-08T23:59:59.000Z
, the micro-SQUID (microscopic superconducting quantum interference device), can be used to detect very small changes in magnetic flux. Most low Tc micro-SQUIDs (LTS) are made from aluminum or niobium. While an aluminum SQUID is relatively easy to fabricate...
Arik, Metin; Kholmetskii, Alexander L
2009-01-01T23:59:59.000Z
Previously, we established a connection between the macroscopic classical laws of gases and the quantum mechanical description of molecules of an ideal gas (T. Yarman et al. arXiv:0805.4494). In such a gas, the motion of each molecule can be considered independently on all other molecules, and thus the macroscopic parameters of the ideal gas, like pressure P and temperature T, can be introduced as a result of simple averaging over all individual motions of the molecules. It was shown that for an ideal gas enclosed in a macroscopic cubic box of volume V, the constant, arising along with the classical law of adiabatic expansion, i.e. PV5/3=constant, can be explicitly derived based on quantum mechanics, so that the constant comes to be proportional to h^2/m; here h is the Planck Constant, and m is the relativistic mass of the molecule the gas is made of. In this article we show that the same holds for a photon gas, although the related setup is quite different than the previous ideal gas setup. At any rate, we c...
Calculating and visualizing the density of states for simple quantum mechanical systems
Declan Mulhall; Matthew Moelter
2014-06-27T23:59:59.000Z
We present a graphical approach to understanding the degeneracy, density of states, and cumulative state number for some simple quantum systems. By taking advantage of basic computing operations we define a straightforward procedure for determining the relationship between discrete quantum energy levels and the corresponding density of states and cumulative level number. The density of states for a particle in a rigid box of various shapes and dimensions is examined and graphed. It is seen that the dimension of the box, rather than its shape, is the most important feature. In addition, we look at the density of states for a multi-particle system of identical bosons built on the single-particle spectra of those boxes. A simple model is used to explain how the $N$-particle density of states arises from the single particle system it is based on.
Phil Attard
2014-06-23T23:59:59.000Z
The probability operator for a generic non-equilibrium quantum system is derived. The corresponding stochastic, dissipative Schr\\"odinger equation is also given. The dissipative and stochastic propagators are linked by the fluctuation-dissipation theorem that is derived from the unitary condition on the time propagator. The dissipative propagator is derived from thermodynamic force and entropy fluctuation operators that are in general non-linear.
Andrei P. Kirilyuk
2014-05-14T23:59:59.000Z
The universal symmetry, or conservation, of complexity underlies any law or principle of system dynamics and describes the unceasing transformation of dynamic information into dynamic entropy as the unique way to conserve their sum, the total dynamic complexity. Here we describe the real world structure emergence and dynamics as manifestation of the universal symmetry of complexity of initially homogeneous interaction between two protofields. It provides the unified complex-dynamic, causally complete origin of physically real, 3D space, time, elementary particles, their properties (mass, charge, spin, etc.), quantum, relativistic, and classical behaviour, as well as fundamental interaction forces, including naturally quantized gravitation. The old and new cosmological problems (including "dark" mass and energy) are basically solved for this explicitly emerging, self-tuning world structure characterised by strictly positive (and large) energy-complexity. A general relation is obtained between the numbers of world dimensions and fundamental forces, excluding plausible existence of hidden dimensions. The unified, causally explained quantum, classical, and relativistic properties (and types of behaviour) are generalised to all higher levels of complex world dynamics. The real world structure, dynamics, and evolution are exactly reproduced by the probabilistic dynamical fractal, which is obtained as the truly complete general solution of a problem and the unique structure of the new mathematics of complexity. We outline particular, problem-solving applications of always exact, but irregularly structured symmetry of unreduced dynamic complexity to microworld dynamics, including particle physics, genuine quantum chaos, real nanobiotechnology, and reliable genomics.
Matteo Villani
2009-07-28T23:59:59.000Z
A theoretical scheme, based on a probabilistic generalization of the Hamilton's principle, is elaborated to obtain an unified description of more general dynamical behaviors determined both from a lagrangian function and by mechanisms not contemplated by this function. Within this scheme, quantum mechanics, classical field theory and a quantum theory for scalar fields are discussed. As a by-product of the probabilistic scheme for classical field theory, the equations of the De Donder-Weyl theory for multi-dimensional variational problems are recovered.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEA :Work with E=mc2 - What's the Speed of Light Got to Do
Minton, Gregory; Sahakian, Vatche [Harvey Mudd College, Physics Department, 241 Platt Boulevard, Claremont, California 91711 (United States)
2008-01-15T23:59:59.000Z
Puff field theories (PFT) arise as the decoupling limits of D3 branes in a Melvin universe and exhibit spatially nonlocal dynamics. Unlike other realizations of nonlocality in string theory, PFTs have full SO(3) rotational symmetry. In this work, we analyze the strongly coupled regime of a PFT through gravitational holography. We find a novel mechanism at the heart of the phenomenon of nonlocality: a quantum entanglement of UV and IR dynamics. In the holographic bulk, this translates to an apparent horizon splitting the space into two regions--with the UV completion of the PFT sitting at the horizon. We unravel this intricate UV-IR setting and devise a prescription for computing correlators that extends the original dictionary of holographic renormalization group. We then implement a cosmological scenario where PFT correlators set the initial conditions for primordial fluctuations. We compute the associated power spectrum of the cosmic microwave background and find that the scenario allows for a distinct stringy signature.
Piscicchia, K; Bartalucci, S; Bassi, A; Bertolucci, S; Berucci, C; Bragadireanu, A M; Cargnelli, M; Clozza, A; De Paolis, L; Di Matteo, S; Donadi, S; d'Uffizi, A; Egger, J-P; Guaraldo, C; Iliescu, M; Ishiwatari, T; Laubenstein, M; Marton, J; Milotti, E; Pietreanu, D; Ponta, T; Sbardella, E; Scordo, A; Shi, H; Sirghi, D L; Sirghi, F; Sperandio, L; Doce, O Vazquez; Zmeskal, J
2015-01-01T23:59:59.000Z
The development of mathematically complete and consistent models solving the so-called "measurement problem", strongly renewed the interest of the scientific community for the foundations of quantum mechanics, among these the Dynamical Reduction Models posses the unique characteristic to be experimentally testable. In the first part of the paper an upper limit on the reduction rate parameter of such models will be obtained, based on the analysis of the X-ray spectrum emitted by an isolated slab of germanium and measured by the IGEX experiment. The second part of the paper is devoted to present the results of the VIP (Violation of the Pauli exclusion principle) experiment and to describe its recent upgrade. The VIP experiment established a limit on the probability that the Pauli Exclusion Principle (PEP) is violated by electrons, using the very clean method of searching for PEP forbidden atomic transitions in copper.
Comment on [open quotes]Nonlocality, counterfactuals, and quantum mechanics[close quotes
Stapp, H.P. (Lawrence Berkeley National Laboratory, University of California at Berkely, Berkeley, California 94720 (United States))
1999-09-01T23:59:59.000Z
A recent proof [H. P. Stapp, Am. J. Phys. [bold 65], 300 (1997)], formulated in the symbolic language of modal logic, claims to show that contemporary quantum theory, viewed as a set of rules that allow us to calculate statistical predictions among certain kinds of observations, cannot be imbedded in any rational framework that conforms to the principles that (1) the experimenters[close quote] choices of which experiments they will perform can be considered to be free choices, (2) outcomes of measurements are unique, and (3) the free choices just mentioned have no backward-in-time effects of any kind. This claim is similar to Bell[close quote]s theorem, but much stronger, because no reality assumption alien to quantum philosophy is used. The paper being commented on [W. Unruh, Phys. Rev. A [bold 59], 126 (1999)] argues that some such reality assumption has been [open quotes]smuggled[close quotes] in. That argument is examined here and shown, I believe, to be defective. [copyright] [ital 1999] [ital The American Physical Society
Rioux, Frank
Quantum Jumps for an Electron in a One-dimensional Box The phrases "quantum jump" and "quantum leap by the nature of the process by which a quantum system passes from one allowed energy state to another. McMillin [J. Chem. Ed. 55, 7 (1978)] has described an appealing model for "quantum jumps" that is referred
Applied quantum mechanics 1 Applied Quantum Mechanics
Levi, Anthony F. J.
3D T 0 K( ) 3 5 ---EF= E3D T K( ) 3 2 ---kBT= E2D T 0 K( ) 1 2 ---EF= E2D T K( ) kBT= a x1 x2 . Your answer should include a print out of your computer program and plots. Problem 7.2 (a) Show that (b) A semiconductor consists of a valance band with electron energy dispersion relation and a conduction band
Explicit Green operators for quantum mechanical Hamiltonians. I. The hydrogen atom
Heinz-Jürgen Flad; Gohar Harutyunyan; Reinhold Schneider; Bert-Wolfgang Schulze
2010-03-16T23:59:59.000Z
We study a new approach to determine the asymptotic behaviour of quantum many-particle systems near coalescence points of particles which interact via singular Coulomb potentials. This problem is of fundamental interest in electronic structure theory in order to establish accurate and efficient models for numerical simulations. Within our approach, coalescence points of particles are treated as embedded geometric singularities in the configuration space of electrons. Based on a general singular pseudo-differential calculus, we provide a recursive scheme for the calculation of the parametrix and corresponding Green operator of a nonrelativistic Hamiltonian. In our singular calculus, the Green operator encodes all the asymptotic information of the eigenfunctions. Explicit calculations and an asymptotic representation for the Green operator of the hydrogen atom and isoelectronic ions are presented.
Noncommutative quantum mechanics of a harmonic oscillator under linearized gravitational waves
Anirban Saha; Sunandan Gangopadhyay; Swarup Saha
2011-06-09T23:59:59.000Z
We consider the quantum dynamics of a harmonic oscillator in noncommutative space under the influence of linearized gravitational waves (GW) in the long wave-length and low-velocity limit. Following the prescription in \\cite{ncgw1} we quantize the system. The Hamiltonian of the system is solved by using standard algebraic iterative methods. The solution shows signatures of the coordinate noncommutativity via alterations in the oscillation frequency of the harmonic oscillator system from its commutative counterpart. Moreover, it is found that the response of the harmonic oscillator to periodic GW, when their frequencies match, will oscillate with a time scale imposed by the NC parameter. We expect this noncommutative signature to show up as some noise source in the GW detection experiments since the recent phenomenological upper-bounds set on spatial noncommutative parameter implies a length-scale comparable to the length-variations due to the passage of gravitational waves, detectable in the present day GW detectors.
A bird's eye view of quantum computers
Giuliano Benenti; Giuliano Strini
2007-03-13T23:59:59.000Z
Quantum computers are discussed in the general framework of computation, the laws of physics and the foundations of quantum mechanics.
Joshua McConaha | Department of Energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
McConaha About Us Joshua McConaha Joshua McConaha is the Deputy Director of Public Affairs for the National Nuclear Security Administration. Most Recent Why the Nuclear...
Representation of quantum mechanical resonances in the Lax-Phillips Hilbert space
Strauss, Y.; Horwitz, L. P.; Eisenberg, E.
2000-01-01T23:59:59.000Z
We discuss the quantum Lax-Phillips theory of scattering and unstable systems. In this framework, the decay of an unstable system is described by a semigroup. The spectrum of the generator of the semigroup corresponds to the singularities of the Lax-Phillips S-matrix. In the case of discrete (complex) spectrum of the generator of the semigroup, associated with resonances, the decay law is exactly exponential. The states corresponding to these resonances (eigenfunctions of the generator of the semigroup) lie in the Lax-Phillips Hilbert space, and therefore all physical properties of the resonant states can be computed. We show that the Lax-Phillips S-matrix is unitarily related to the S-matrix of standard scattering theory by a unitary transformation parametrized by the spectral variable ? of the Lax-Phillips theory. Analytic continuation in ? has some of the properties of a method developed some time ago for application to dilation analytic potentials. We work out an illustrative example using a Lee-Friedrichs model for the underlying dynamical system.
Kuechler, Erich R. [BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 (United States) [BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 (United States); Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States); York, Darrin M., E-mail: york@biomaps.rutgers.edu [BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 (United States)
2014-02-07T23:59:59.000Z
The nucleophilic attack of a chloride ion on methyl chloride is an important prototype S{sub N}2 reaction in organic chemistry that is known to be sensitive to the effects of the surrounding solvent. Herein, we develop a highly accurate Specific Reaction Parameter (SRP) model based on the Austin Model 1 Hamiltonian for chlorine to study the effects of solvation into an aqueous environment on the reaction mechanism. To accomplish this task, we apply high-level quantum mechanical calculations to study the reaction in the gas phase and combined quantum mechanical/molecular mechanical simulations with TIP3P and TIP4P-ew water models and the resulting free energy profiles are compared with those determined from simulations using other fast semi-empirical quantum models. Both gas phase and solution results with the SRP model agree very well with experiment and provide insight into the specific role of solvent on the reaction coordinate. Overall, the newly parameterized SRP Hamiltonian is able to reproduce both the gas phase and solution phase barriers, suggesting it is an accurate and robust model for simulations in the aqueous phase at greatly reduced computational cost relative to comparably accurate ab initio and density functional models.
Gerold Doyen; Deiana Drakova
2014-08-12T23:59:59.000Z
We construct a world model consisting of a matter field living in 4 dimensional spacetime and a gravitational field living in 11 dimensional spacetime. The seven hidden dimensions are compactified within a radius estimated by reproducing the particle - wave characteristic of diffraction experiments. In the presence of matter fields the gravitational field develops localized modes with elementary excitations called gravonons which are induced by the sources (massive particles). The final world model treated here contains only gravonons and a scalar matter field. The solution of the Schroedinger equation for the world model yields matter fields which are localized in the 4 dimensional subspace. The localization has the following properties: (i) There is a chooser mechanism for the selection of the localization site. (ii) The chooser selects one site on the basis of minor energy differences and differences in the gravonon structure between the sites, which appear statistical. (iii) The changes from one localization site to a neighbouring one take place in a telegraph-signal like manner. (iv) The times at which telegraph like jumps occur dependent on subtleties of the gravonon structure which appear statistical. (v) The fact that the dynamical law acts in the configuration space of fields living in 11 dimensional spacetime lets the events observed in 4 dimensional spacetime appear non-local. In this way the phenomenology of Copenhagen quantum mechanics is obtained without the need of introducing the process of collapse and a probabilistic interpretation of the wave function. Operators defining observables need not be introduced. All experimental findings are explained in a deterministic way as a consequence of the time development of the wave function in configuration space according to Schroedinger's equation.
J. H. Field
2005-03-02T23:59:59.000Z
Feynman's laws of quantum dynamics are concisely stated, discussed in comparison with other formulations of quantum mechanics and applied to selected problems in the physical optics of photons and massive particles as well as flavour oscillations. The classical wave theory of light is derived from these laws for the case in which temporal variation of path amplitudes may be neglected, whereas specific experiments, sensitive to the temporal properties of path amplitudes, are suggested. The reflection coefficient of light from the surface of a transparent medium is found to be markedly different to that predicted by the classical Fresnel formula. Except for neutrino oscillations, good agreement is otherwise found with previous calculations of spatially dependent quantum interference effects.
Broader source: Energy.gov [DOE]
Mr. McDonald has more than 34 years of nuclear related experience with DOE contractors at the Hanford site, commercial nuclear power industry at multiple facilities, and served as an officer in the US Navy submarine program.
Castagnoli, Giuseppe [Via San Bernardo 9/A, I-16030 Pieve Ligure (Genova) (Italy)
2010-11-15T23:59:59.000Z
In classical problem solving, there is, of course, correlation between the selection of the problem on the part of Bob (the problem setter) and that of the solution on the part of Alice (the problem solver). In quantum problem solving, this correlation becomes quantum. This means that Alice contributes to selecting 50% of the information that specifies the problem. As the solution is a function of the problem, this gives to Alice advanced knowledge of 50% of the information that specifies the solution. Both the quadratic and exponential speed-ups are explained by the fact that quantum algorithms start from this advanced knowledge.
M. V. Gorbatenko; V. P. Neznamov
2014-11-08T23:59:59.000Z
In the paper we analyze the quantum-mechanical equivalence of the metrics of a centrally symmetric uncharged gravitational field. We consider the Schwarzschild metrics in the spherical, isotropic and harmonic coordinates, and the Eddington-Finkelstein, Painleve-Gullstrand, Lemaitre-Finkelstein, Kruskal metrics. The scope of the analysis includes domains of the wave functions of Dirac's equation, hermiticity of Hamiltonians, and the possibility of existence of stationary bound states of spin-half particles. The constraint on the domain of the wave functions of the Hamiltonian in a Schwarzschild field in spherical coordinates (r > r_{0}) resulting from the fulfillment of Hilbert's condition g_{00} > 0 also holds in other coordinates for all the metrics considered. The self-adjoint Hamiltonians for the Schwarzschild metrics in the spherical, isotropic and harmonic coordinates and also for the Eddington-Finkelstein and Painleve-Gullstrand metrics are Hermitian, and for them the existence of stationary bound states of spin-half particles is possible. The self-adjoint Hamiltonians for non-stationary Lemaitre-Finkelstein and Kruskal metrics have the explicit dependence on the temporal coordinates and stationary bound states of spin-half particles cannot be defined for these Hamiltonians. The results of this study can be useful when addressing the issues related to the evolution of the universe and interaction of collapsars with surrounding matter.
Benioff, P.
1980-01-01T23:59:59.000Z
A microscopic quantum mechanical model of computers as represented by Turing machines is constructed. It is shown that for each number N and Turing machine Q there exists a Hamiltonian H/sub N//sup Q/ and a class of appropriate initial states such that, if PSI/sub Q//sup N/(0) is such an initial state, then PSI/sub Q//sup N/(t) = exp(-iH/sub N//sup Q/t) PSI/sub Q//sup N/(0) correctly describes at times t/sub 3/, t/sub 6/,..., t/sub 3N/ model states that correspond to the completion of the first, second,..., Nth computation step of Q. The model parameters can be adjusted so that for an arbitrary time interval ..delta.. around t/sub 3/, t/sub 6/,..., t/sub 3N/, the machine part of PSI/sub Q//sup N/(t) is stationary. 1 figure.
Property of Zero-Energy Flows and Creations and Annihilations of Vortices in Quantum Mechanics
Tsunehiro Kobayashi
2003-01-09T23:59:59.000Z
Time-dependent processes accompanied by vortex creations and annihilations are investigated in terms of the eigenstates in conjugate spaces of Gel'fand triplets in 2-dimensions. Creations and annihilations of vortices are described by the insertions of unstable eigenstates with complex-energy eigenvalues into stable states written by the superposition of eigenstates with zero-energy eigenvalues. Some concrete examples are presented in terms of the eigenfunctions of the 2-dimensional parabolic potential barrier, i.e., $-m \\gamma^2 (x^2+y^2)/2$. We show that the processes accompanied by vortex creations and annihilations can be analyzed in terms of the eigenfunctions in the conjugate spaces of Gel'fand triplets. Throughout these examinations we point out three interesting properties of the zero-energy flows. (i) Mechanisms using the zero-energy flows are absolutely economical from the viewpoint of energy consumption. (ii) An enormous amount of informations can be discriminated in terms of the infinite variety of the zero-energy flows. (iii) The zero-energy flow patterns are absolutely stable in any disturbance by inserting arbitrary decaying flows with complex-energy eigenvalues.
Quantum Thermodynamic Cycles and Quantum Heat Engines (II)
H. T. Quan
2009-03-09T23:59:59.000Z
We study the quantum mechanical generalization of force or pressure, and then we extend the classical thermodynamic isobaric process to quantum mechanical systems. Based on these efforts, we are able to study the quantum version of thermodynamic cycles that consist of quantum isobaric process, such as quantum Brayton cycle and quantum Diesel cycle. We also consider the implementation of quantum Brayton cycle and quantum Diesel cycle with some model systems, such as single particle in 1D box and single-mode radiation field in a cavity. These studies lay the microscopic (quantum mechanical) foundation for Szilard-Zurek single molecule engine.
Constantinos Kalapotharakos; Christos Efthymiopoulos; Nikos Voglis
2007-09-06T23:59:59.000Z
We address the question of an appropriate choice of basis functions for the self-consistent field (SCF) method of simulation of the N-body problem. Our criterion is based on a comparison of the orbits found in N-body realizations of analytical potential-density models of triaxial galaxies, in which the potential is fitted by the SCF method using a variety of basis sets, with those of the original models. Our tests refer to maximally triaxial Dehnen gamma-models for values of $\\gamma$ in the range 0<=gamma<=1. When an N-body realization of a model is fitted by the SCF method, the choice of radial basis functions affects significantly the way the potential, forces, or derivatives of the forces are reproduced, especially in the central regions of the system. We find that this results in serious discrepancies in the relative amounts of chaotic versus regular orbits, or in the distributions of the Lyapunov characteristic exponents, as found by different basis sets. Numerical tests include the Clutton-Brock and the Hernquist-Ostriker (HO) basis sets, as well as a family of numerical basis sets which are `close' to the HO basis set. The family of numerical basis sets is parametrized in terms of a quantity $\\epsilon$ which appears in the kernel functions of the Sturm-Liouville (SL) equation defining each basis set. The HO basis set is the $\\epsilon=0$ member of the family. We demonstrate that grid solutions of the SL equation yielding numerical basis sets introduce large errors in the variational equations of motion. We propose a quantum-mechanical method of solution of the SL equation which overcomes these errors. We finally give criteria for a choice of optimal value of $\\epsilon$ and calculate the latter as a function of the value of gamma.
Quantum Signatures of Spacetime Graininess Quantum Signatures of Spacetime
Quantum Field Theory on Noncommutative Spacetime Implementing Poincaré Symmetry Hopf Algebras, Drinfel Quantum Mechanics on Noncommutative Spacetime 4 Quantum Field Theory on Noncommutative Spacetime Covariant Derivatives and Field Strength Noncommutative Gauge Theories 6 Signatures of Spin
NMR quantum information processing
Dawei Lu; Aharon Brodutch; Jihyun Park; Hemant Katiyar; Tomas Jochym-O'Connor; Raymond Laflamme
2015-01-07T23:59:59.000Z
Quantum computing exploits fundamentally new models of computation based on quantum mechanical properties instead of classical physics, and it is believed that quantum computers are able to dramatically improve computational power for particular tasks. At present, nuclear magnetic resonance (NMR) has been one of the most successful platforms amongst all current implementations. It has demonstrated universal controls on the largest number of qubits, and many advanced techniques developed in NMR have been adopted to other quantum systems successfully. In this review, we show how NMR quantum processors can satisfy the general requirements of a quantum computer, and describe advanced techniques developed towards this target. Additionally, we review some recent NMR quantum processor experiments. These experiments include benchmarking protocols, quantum error correction, demonstrations of algorithms exploiting quantum properties, exploring the foundations of quantum mechanics, and quantum simulations. Finally we summarize the concepts and comment on future prospects.
Khan, Shabbir A
2013-01-01T23:59:59.000Z
Quantum plasma physics is a rapidly evolving research field with a very inter-disciplinary scope of potential applications, ranging from nano-scale science in condensed matter to the vast scales of astrophysical objects. The theoretical description of quantum plasmas relies on various approaches, microscopic or macroscopic, some of which have obvious relation to classical plasma models. The appropriate model should, in principle, incorporate the quantum mechanical effects such as diffraction, spin statistics and correlations, operative on the relevant scales. However, first-principle approaches such as quantum Monte Carlo and density functional theory or quantum-statistical methods such as quantum kinetic theory or non-equilibrium Green's functions require substantial theoretical and computational efforts. Therefore, for selected problems, alternative simpler methods have been put forward. In particular, the collective behavior of many-body systems is usually described within a self-consistent scheme of parti...
Fujihashi, Yuta; Ishizaki, Akihito
2015-01-01T23:59:59.000Z
Recently, nuclear vibrational contribution signatures in 2D electronic spectroscopy have attracted considerable interest, in particular as regards interpretation of the oscillatory transients observed in light-harvesting complexes. These transients have dephasing times that persist for much longer than theoretically predicted electronic coherence lifetime. As a plausible explanation for this long-lived spectral beating in 2D electronic spectra, quantum-mechanically mixed electronic and vibrational states (vibronic excitons) were proposed by Christensson et al. [J. Phys. Chem. B 116, 7449 (2012)] and have since been explored. In this work, we address a dimer which produces little beating of electronic origin in the absence of vibronic contributions, and examine the impact of protein-induced fluctuations upon electronic-vibrational quantum mixtures by calculating the electronic energy transfer dynamics and 2D electronic spectra in a numerically accurate manner. It is found that, at cryogenic temperatures, the e...
Teich, Malvin C.
electron transition mechanisms. tum efficiencyassociatedwith the mechanismsindicatedby arrows 3 and 4
Roweis, Sam
CSC310 -- Information Theory Sam Roweis Lecture 3: Proving the KraftMcMillan Inequalities) Modeling. We have to represent the stochastic behaviour of the source and the channel using probabilistic. Review: Mathematical Setup 3 . A stochastic source emits a sequence of symbols (from alphabet A) X = X1
Smith, J.
2011-01-01T23:59:59.000Z
CATEE Conference: Planning for Sustainability McKinney?s Draft Community Sustainability Plan: Shaping Our Sustainable Future Julie Smith Office of Environmental Stewardship November 8, 2011 Sustainability Planning ? Why bother? ? Who has... aspect of sustainability ? Created the Green Advisory Committee (GAC) ? November 2008: Green Sustainability Initiative Report ? Recommended forming a comprehensive, sustainability program to coordinate the sustainability agenda for the city...
McMASTER UNIVERSITY CONSOLIDATED BUDGET
Haykin, Simon
McMASTER UNIVERSITY 2011/12 CONSOLIDATED BUDGET Approved by the Board of Governors June 2011 #12;McMaster University Consolidated Budget for 2011/12 Table of Contents LIST OF TABLES .......................................... 13 THE BUDGET PROCESS
McMASTER UNIVERSITY CONSOLIDATED BUDGET
Thompson, Michael
McMASTER UNIVERSITY 2010/11 CONSOLIDATED BUDGET Approved by the Board of Governors June 2010 #12;McMaster University Consolidated Budget for 2010/11 Table of Contents LIST OF TABLES.................................................................................................................... 1 OPERATING FUND BUDGET
McMASTER UNIVERSITY CONSOLIDATED BUDGET
Haykin, Simon
McMASTER UNIVERSITY 2012/13 CONSOLIDATED BUDGET Approved by the Board of Governors June 7, 2012 #12;McMaster University Consolidated Budget for 2012/13 Table of Contents LIST OF TABLES .............................................................................................................. 6 THE BUDGET PROCESS
THE MC AND A COUNCIL AT SSC RF - IPPE AS A COORDINATING BODY FOR SYSTEM SUSTAINABILITY.
FISHBONE,L.VALENTE,J.HANLEY,T.HIRSCHI,E.J.RUSS,P.SCHERER-KATZ,C.
2004-07-18T23:59:59.000Z
The State Scientific Center of the Russian Federation--Institute of Physics and Power Engineering's (SSC RF-IPPE) practice of nuclear material control and accounting (MC&A) has undergone significant changes during the period of cooperation with U.S. national laboratories from 1995 to the present. These changes corresponded with general changes of the Russian system of state control and accounting of nuclear materials resulting from the new Concept of the System for State Regulating and Control of Nuclear Materials (1996) and further regulatory documents, which were developed and implemented to take into account international experience in the MC&A [1]. During the upgrades phase of Russian-U.S. cooperation, an MC&A laboratory was specially created within the SSC RF IPPE for the purpose of guiding the creation of the upgraded MC&A system, coordinating the activities of all units involved in the creation of this system, and implementing a unified technical policy during the transition period. After five years of operation of the MC&A laboratory and the implementation of new components for the upgraded MC&A system, it was decided that a greater degree of attention must be paid to the MC&A system's operation in addition to the coordination activities carried out by the MC&A laboratory. To meet this need, an organization for operation of the nuclear material (NM) control and accounting system was created as part of the Division of NM Transportation and Storage. It was also recognized that a new mechanism was required for effective coordination of MC&A activities in IPPE, including the implementation of a unified MC&A policy in methodological, technical and practical areas. This mechanism should allow the IPPE management to gain an objective evaluation of the MC&A system status and provide leading specialists with objective recommendations on maintenance of MC&A system and on basic directions for further improvements. Preliminary discussions indicated that such a mechanism could be created through the establishment of an MC&A Council at SSC RF-IPPE. The MC&A Council has been created in SSC RF-IPPE as an advisory body without administrative functions. However it is stated in the Council Regulations that if the IPPE Director General or his Deputy responsible for NM control and accounting approves Council recommendations, the recommendations become obligatory. In this paper, the experience of the Council and its initial activities are presented and discussed in, as are possible activities and roles the Council could play in the future.
Svetlichny, George
2011-01-01T23:59:59.000Z
I contemplate the idea that the subjective world and quantum state reductions are one and the same. If true, this resolves with one stroke both the quantum mechanical measurement problem and the hard problem of consciousness.
George Svetlichny
2011-04-13T23:59:59.000Z
I contemplate the idea that the subjective world and quantum state reductions are one and the same. If true, this resolves with one stroke both the quantum mechanical measurement problem and the hard problem of consciousness.
Goddard III, William A.
Hydrogen storage in LiAlH4 : Predictions of the crystal structures and reaction mechanisms in decomposition of the potential hydrogen storage material LiAlH4 . First, we explore the decomposition mechanism of monoclinic LiAlH4 into monoclinic Li3AlH6 plus face-centered cubic fcc Al and hydrogen. We find
McMaster University Risk Management
Thompson, Michael
McMaster University Risk Management Manual RMM # 304 Title: Persons Working Alone Date: Dec 2002 Page: 1 of 10 Submitted: Risk Management Support Group Approved: Karen Belaire Vice President.10 McMaster University Standard Operating Procedures Policy. #12;McMaster University Risk Management
McMaster Security 2012 Annual Report
Thompson, Michael
McMaster Security Services 2012 Annual Report #12;McMaster Security Services Annual Report 2012 2 Mission Statement Developing a safe and secure environment in this academic institution within the McMaster community is assigned to the Security Services Department. Methods and approaches
An Introduction to Quantum Control
James, Matthew
, stochastic control, quantum control, systems biology, networks, etc modern control #12;Quantum Control: Control of physical systems whose behaviour is dominated by the laws of quantum mechanics. 2003: Dowling of Quantum Control: controller quantum system control actions #12;· Closed loop - control actions depend
F. A. Muller
2014-06-21T23:59:59.000Z
The quest for finding the right interpretation of Quantum Mechanics (QM) is as old als QM and still has not ended, and may never end. The question what an interpretation of QM is has hardly ever been raised explicitly, let alone answered. We raise it and answer it. Then the quest for the right interpretation can continue self-consciously, for we then know exactly what we are after. We present a list of minimal requirements that something has to meet in order to qualify as an interpretation of QM. We also raise, as a side issue, the question how the discourse on the interpretation of QM relates to hermeneutics in Continental Philosophy.
Joseph F. Johnson
2006-06-15T23:59:59.000Z
From the standpoint of Hilbert's Sixth Problem, which is the axiomatisation of Physics, the famous paper of Lucien Hardy's, Quantum Theory from Five Reasonable Axioms, is not relevant. The present paper argues that Hardy does not give a physical definition of `limit', and if we assume the usual mathematical definition of limit of a sequence, he fails to define a sequence in physical terms to which the usual definition is applicable. We argue that one should not, in fact, try to define probability in terms of the usual notion of limit of a sequence of results of a measurement because of seemingly insurmountable difficulties in axiomatising the notion of function or sequence in this context. Von Plato's and the authour's work (see http:arxiv.org/abs/quant-ph/0502124 and euclid.unh.edu/~jjohnson/axiomatics.html for larger context and further references) on the definition of physical probability needs to be used in this context. We conclude with ten theses on quantum measurement, from the standpoint of the Hilbert problem.
Fabrication of planar quantum magnetic disk structure using electron beam lithography, reactive ion, Department of Electrical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 Received 2 June's size and location, and reactive ion etching was used to form an SiO2 template. Nickel electroplating
Smets, Quentin; Verreck, Devin; Vandervorst, Wilfried; Groeseneken, Guido; Heyns, Marc M. [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); KULeuven, 3001 Leuven (Belgium); Verhulst, Anne S.; Rooyackers, Rita; Merckling, Clément; Simoen, Eddy; Collaert, Nadine; Thean, Voon Y. [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); Van De Put, Maarten; Sorée, Bart [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); Universiteit Antwerpen, 2020 Antwerpen (Belgium)
2014-05-14T23:59:59.000Z
Promising predictions are made for III-V tunnel-field-effect transistor (FET), but there is still uncertainty on the parameters used in the band-to-band tunneling models. Therefore, two simulators are calibrated in this paper; the first one uses a semi-classical tunneling model based on Kane's formalism, and the second one is a quantum mechanical simulator implemented with an envelope function formalism. The calibration is done for In{sub 0.53}Ga{sub 0.47}As using several p+/intrinsic/n+ diodes with different intrinsic region thicknesses. The dopant profile is determined by SIMS and capacitance-voltage measurements. Error bars are used based on statistical and systematic uncertainties in the measurement techniques. The obtained parameters are in close agreement with theoretically predicted values and validate the semi-classical and quantum mechanical models. Finally, the models are applied to predict the input characteristics of In{sub 0.53}Ga{sub 0.47}As n- and p-lineTFET, with the n-lineTFET showing competitive performance compared to MOSFET.
On the Quantum Aspects of Geophysics
F. Darabi
2004-10-10T23:59:59.000Z
We introduce a simple quantum mechanical justification for the formation of folded mountains. It is very appealing to develop this idea to a theory of {\\it Quantum Geophysics}
Proton diffusion pathways and rates in Y-doped BaZrO3 solid oxide electrolyte from quantum mechanics
Goddard III, William A.
Proton diffusion pathways and rates in Y-doped BaZrO3 solid oxide electrolyte from quantum barriers for intraoctahedral and interoctahedral proton transfers. We find activation energy Ea values of 0.48 and 0.49 eV for the intraoctahedral proton transfers on OO edges 2.58 and 2.59 Å of ZrO6 and YO6
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEA :Work4/11ComputationalEdNERSC: DeliveringEdwin M. McMillan
[2], James E. McClure and Jeffrey H. Smith. Operads and cosimplicial objects: an introduction. In Axiomatic, enriched and motivic homotopy theory, volume 131 ...
North Carolina Nuclear Profile - McGuire
U.S. Energy Information Administration (EIA) Indexed Site
McGuire" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...
Some foundational aspects of quantum computers and quantum robots.
Benioff, P.; Physics
1998-01-01T23:59:59.000Z
This paper addresses foundational issues related to quantum computing. The need for a universally valid theory such as quantum mechanics to describe to some extent its own validation is noted. This includes quantum mechanical descriptions of systems that do theoretical calculations (i.e. quantum computers) and systems that perform experiments. Quantum robots interacting with an environment are a small first step in this direction. Quantum robots are described here as mobile quantum systems with on-board quantum computers that interact with environments. Included are discussions on the carrying out of tasks and the division of tasks into computation and action phases. Specific models based on quantum Turing machines are described. Differences and similarities between quantum robots plus environments and quantum computers are discussed.
University of Minnesota McNair Scholars: Faculty Mentor Handbook
Minnesota, University of
University of Minnesota McNair Scholars: Faculty Mentor Handbook 1. Welcome to McNair 2. Goals and Program Structure 3. Why McNair Scholars? 4. McNair Program Objectives 5. McNair Faculty Mentors · General Tips for Mentors · Tips for Mentor as Researcher/Teacher · Faculty Mentor Time Commitment 6. Past
Nikolai N. Bogolubov, Jr.; Anatoliy K. Prykarpatsky
2008-10-21T23:59:59.000Z
The main fundamental principles characterizing the vacuum field structure are formulated and the modeling of the related vacuum medium and charged point particle dynamics by means of devised field theoretic tools are analyzed. The work is devoted to studying the vacuum structure, special relativity, electrodynamics of interacting charged point particles and quantum mechanics, and is a continuation of \\cite{BPT,BRT1}. Based on the vacuum field theory no-geometry approach, the Lagrangian and Hamiltonian reformulation of some alternative classical electrodynamics models is devised. The Dirac type quantization procedure, based on the canonical Hamiltonian formulation, is developed for some alternative electrodynamics models. Within an approach developed a possibility of the combined description both of electrodynamics and gravity is analyzed.
Quantum Computing, Metrology, and Imaging
Hwang Lee; Pavel Lougovski; Jonathan P. Dowling
2005-06-17T23:59:59.000Z
Information science is entering into a new era in which certain subtleties of quantum mechanics enables large enhancements in computational efficiency and communication security. Naturally, precise control of quantum systems required for the implementation of quantum information processing protocols implies potential breakthoughs in other sciences and technologies. We discuss recent developments in quantum control in optical systems and their applications in metrology and imaging.
Quantum information processing in continuous time
Childs, Andrew MacGregor, 1977-
2004-01-01T23:59:59.000Z
Quantum mechanical computers can solve certain problems asymptotically faster than any classical computing device. Several fast quantum algorithms are known, but the nature of quantum speedup is not well understood, and ...
Indirect exporters Fergal McCann
Boyer, Edmond
Indirect exporters Fergal McCann Paris School of Economics Université Paris 1 November 2010 G;Indirect Exporters Fergal McCann Universit´e Paris 1, Paris School of Economics. November 3, 2010 Abstract Indirect Exporters are defined as firms exporting through a trade inter- mediary. Despite numerous recent
McKinley, Buffy; Manning, Sean
2010-05-11T23:59:59.000Z
Oral history interview with Buffy McKinley conducted by Sean Manning in Lawrence, Kansas, on May 11, 2010. In this interview, Buffy McKinley discusses her experiences with the Wiccan/pagan community in Lawrence, Kansas. This interview was conducted...
Douglas W. McCowan Publications
Yang, Zong-Liang
Â1538. McCowan, D. W., Glover, P., and Alexander, S. S., 1978, A crust and upper mantle structure for NovayaÂ544. McCowan, D. W., Glover, P., and Alexander, S. S., 1977, A static and dynamic finite element analysis., and Glover, P., 1973, Numerical calcul
MC Appliance: Order (2012-CE-1508)
Broader source: Energy.gov [DOE]
DOE ordered CNA International Inc. d/b/a MC Appliance Corporation to pay a $8,000 civil penalty after finding MC Appliance had failed to certify that certain models of room air conditioners comply with the applicable energy conservation standards.
McGill University School of Architecture
Barthelat, Francois
McGill University School of Architecture Architecture, Design, and Environments 15-16 January 2008 Michael Jemtrud, Associate Professor and Director McGill University School of Architecture, Montréal;Vernacular Architecture and Community Design · Robert Mellin, Associate Professor · Griffintown Studio #12
Chang, K Y Samuel
2015-01-01T23:59:59.000Z
"Alchemical" interpolation paths, i.e.~coupling systems along fictitious paths that without realistic correspondence, are frequently used within materials and molecular modeling and simulation protocols for the estimation of relative changes in state functions such as free energies. We discuss alchemical changes in the context of quantum chemistry, and present illustrative numerical results for the changes of HOMO eigenvalues of the He atom due to a linear alchemical teleportation---the simultaneous annihilation and creation of nuclear charges at different locations. To demonstrate the predictive power of alchemical first order derivatives (Hellmann-Feynman) the covalent bond potential of hydrogen fluoride and hydrogen chloride is investigated, as well as the van-der-Waals binding in the water-water and water-hydrogen fluoride dimer, respectively. Based on converged electron densities for one configuration, the versatility of alchemical derivatives is exemplified for the screening of entire binding potentials...
Goddard III, William A.
States b Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Hypergolic bipropellants are fuel-oxidizer combinations that ignite spontaneously upon mixing at ambient it important to develop computa- tional fluid dynamics (CFD) models to gain insight into the influ- ence
Ortiz, Michael
across several disciplines such as surface chemistry and catalysis, applied physics, metallurgy and on-the-fly kinetic Monte Carlo simulations A. Ramasubramaniam Program in Applied and Computational) Department of Mechanical and Aerospace Engineering and Program in Applied and Computational Mathematics
MC and A instrumentation catalog
Neymotin, L. [ed.] [Brookhaven National Lab., Upton, NY (United States); Sviridova, V. [ed.] [All-Russian Research Inst. of Automatics, Moscow (Russian Federation)
1998-06-01T23:59:59.000Z
In 1981 and 1985, two editions of a catalog of non-destructive nuclear measurement instrumentation, and material control and surveillance equipment, were published by Brookhaven National Laboratory (BNL). The last edition of the catalog included one hundred and twenty-five entries covering a wide range of devices developed in the US and abroad. More than ten years have elapsed since the publication of the more recent Catalog. Devices described in it have undergone significant modifications, and new devices have been developed. Therefore, in order to assist specialists in the field of Material Control and Accounting (MC and A), a new catalog has been created. Work on this instrumentation catalog started in 1997 as a cooperative effort of Brookhaven National Laboratory (BNL), operated by Brookhaven Science Associates under contract to the US Department of Energy, and the All-Russian Research Institute of Automatics (VNIIA), subordinate institute of the Atomic Energy Ministry of the Russian Federation, within the collaborative US-Russia Material Protection, Control, and Accounting (MPC and A) Program. Most of the equipment included in the Catalog are non-destructive assay (NDA) measurement devices employed for purposes of accounting, confirmation, and verification of nuclear materials. Other devices also included in the Catalog are employed in the detection and deterrence of unauthorized access to or removal of nuclear materials (material control: containment and surveillance). Equipment found in the Catalog comprises either: (1) complete devices or systems that can be used for MC and A applications; or (2) parts or components of complete systems, such as multi-channel analyzers, detectors, neutron generators, and software. All devices are categorized by their status of development--from prototype to serial production.
Mingsheng Ying; Yuan Feng
2007-01-04T23:59:59.000Z
Loop is a powerful program construct in classical computation, but its power is still not exploited fully in quantum computation. The exploitation of such power definitely requires a deep understanding of the mechanism of quantum loop programs. In this paper, we introduce a general scheme of quantum loops and describe its computational process. The notions of termination and almost termination are proposed for quantum loops, and the function computed by a quantum loop is defined. To show their expressive power, quantum loops are applied in describing quantum walks. Necessary and sufficient conditions for termination and almost termination of a general quantum loop on any mixed input state are presented. A quantum loop is said to be (almost) terminating if it (almost) terminates on any input state. We show that a quantum loop is almost terminating if and only if it is uniformly almost terminating. It is observed that a small disturbance either on the unitary transformation in the loop body or on the measurement in the loop guard can make any quantum loop (almost) terminating. Moreover, a representation of the function computed by a quantum loop is given in terms of finite summations of matrices. To illustrate the notions and results obtained in this paper, two simplest classes of quantum loop programs, one qubit quantum loops, and two qubit quantum loops defined by controlled gates, are carefully examined.
Numerical Modeling At Dixie Valley Geothermal Area (McKenna ...
McKenna & Blackwell, 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Dixie Valley Geothermal Area (McKenna &...
Adams, Allan
Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical and that do not have a simple description in terms of weakly interacting quasiparticles. Two systems that have recently ...
Joseph A. McBrearty- Biography
Broader source: Energy.gov [DOE]
Joseph McBrearty joined the Office of Science in August 2010 immediately upon retiring from a 30-year career in the U.S. Navy, where he specialized in nuclear propulsion and nuclear weapons systems, training, control and safety.
MC Appliance: Proposed Penalty (2014-CE-20002)
Broader source: Energy.gov [DOE]
DOE alleged in a Notice of Proposed Civil Penalty that MC Appliance Corporation failed to certify residential clothes washers and residential clothes dryers as compliant with the applicable energy conservation standards.
Model checking quantum Markov chains
Yuan Feng; Nengkun Yu; Mingsheng Ying
2013-11-14T23:59:59.000Z
Although the security of quantum cryptography is provable based on the principles of quantum mechanics, it can be compromised by the flaws in the design of quantum protocols and the noise in their physical implementations. So, it is indispensable to develop techniques of verifying and debugging quantum cryptographic systems. Model-checking has proved to be effective in the verification of classical cryptographic protocols, but an essential difficulty arises when it is applied to quantum systems: the state space of a quantum system is always a continuum even when its dimension is finite. To overcome this difficulty, we introduce a novel notion of quantum Markov chain, specially suited to model quantum cryptographic protocols, in which quantum effects are entirely encoded into super-operators labelling transitions, leaving the location information (nodes) being classical. Then we define a quantum extension of probabilistic computation tree logic (PCTL) and develop a model-checking algorithm for quantum Markov chains.
Model checking quantum Markov chains
Feng, Yuan; Ying, Mingsheng
2012-01-01T23:59:59.000Z
Although the security of quantum cryptography is provable based on the principles of quantum mechanics, it can be compromised by the flaws in the design of quantum protocols and the noise in their physical implementations. So, it is indispensable to develop techniques of verifying and debugging quantum cryptographic systems. Model-checking has proved to be effective in the verification of classical cryptographic protocols, but an essential difficulty arises when it is applied to quantum systems: the state space of a quantum system is always a continuum even when its dimension is finite. To overcome this difficulty, we introduce a novel notion of quantum Markov chain, specially suited to model quantum cryptographic protocols, in which quantum effects are entirely encoded into super-operators labelling transitions, leaving the location information (nodes) being classical. Then we define a quantum extension of probabilistic computation tree logic (PCTL) and develop a model-checking algorithm for quantum Markov c...
34 McCormick / spring Lead mechanical engineer, Titan Aerospace
Chen, Wei
and solar panels. Anyway, I learned about the job through a solar car listserv. I contacted him and becameCormick: What does Titan Aerospace do? Cornew: Titan Aerospace is a startup that designs and builds solar-powered unmanned aerial vehicles, or drones. Our long-term goal is to build solar-powered UAVs that could stay
The Mechanized Verification of Garbage Collector Implementations
Abstract The Mechanized Verification of Garbage Collector Implementations Andrew Evan Mc complex, requiring a garbage collector. Garbage collectors are becoming increasingly sophis- ticated to adapt them to high-performance, concurrent and real-time applications, making internal collector
autonomous resistance mechanism: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
McFaline-Figueroa, Jos L 2014-01-01 8 Original article Mechanisms of resistance to acrolein Physics Websites Summary: Original article Mechanisms of resistance to acrolein in...
Sassoli de Bianchi, Massimiliano, E-mail: autoricerca@gmail.com
2013-09-15T23:59:59.000Z
In a letter to Born, Einstein wrote [42]: “Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the ‘old one.’ I, at any rate, am convinced that He does not throw dice.” In this paper we take seriously Einstein’s famous metaphor, and show that we can gain considerable insight into quantum mechanics by doing something as simple as rolling dice. More precisely, we show how to perform measurements on a single die, to create typical quantum interference effects, and how to connect (entangle) two identical dice, to maximally violate Bell’s inequality. -- Highlights: •Rolling a die is a quantum process admitting a Hilbert space representation. •Rolling experiments with a single die can produce interference effects. •Two connected dice can violate Bell’s inequality. •Correlations need to be created by the measurement, to violate Bell’s inequality.
Ari Mizel
2003-12-09T23:59:59.000Z
Ground-state quantum computers mimic quantum mechanical time evolution within the amplitudes of a time-independent quantum state. We explore the principles that constrain this mimicking. A no-cloning argument is found to impose strong restrictions. It is shown, however, that there is flexibility that can be exploited using quantum teleportation methods to improve ground-state quantum computer design.
The Campaign for McMaster University The Campaign for McMaster University
Hitchcock, Adam P.
Master University Â· Financial Procedure for Research Grants Â· Indirect Costs Associated with Research Funding fromThe Campaign for McMaster University The Campaign for McMaster University Research Integrity Policy Orientation Michelle Bennett University Secretariat Kimberly Mason Office of Academic Integrity Kathy Charters
aggression control mechanisms: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
A feedback mechanism based on hamiltonian tracking Quantum Physics (arXiv) Summary: Enviroment - caused dissipation disrupts the hamiltonian evolution of all quantum systems...
autocrine feedback mechanism: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
A feedback mechanism based on hamiltonian tracking Quantum Physics (arXiv) Summary: Enviroment - caused dissipation disrupts the hamiltonian evolution of all quantum systems...
Axel Friedenauer; Hector Schmitz; Jan Tibor Glückert; Diego Porras; Tobias Schätz
2008-02-27T23:59:59.000Z
To gain deeper insight into the dynamics of complex quantum systems we need a quantum leap in computer simulations. We can not translate quantum behaviour arising with superposition states or entanglement efficiently into the classical language of conventional computers. The final solution to this problem is a universal quantum computer [1], suggested in 1982 and envisioned to become functional within the next decade(s); a shortcut was proposed via simulating the quantum behaviour of interest in a different quantum system, where all parameters and interactions can be controlled and the outcome detected sufficiently well. Here we study the feasibility of a quantum simulator based on trapped ions [2]. We experimentally simulate the adiabatic evolution of the smallest non-trivial spin system from the paramagnetic into the (anti-)ferromagnetic order with a quantum magnetisation for two spins of 98%, controlling and manipulating all relevant parameters of the Hamiltonian independently via electromagnetic fields. We prove that the observed transition is not driven by thermal fluctuations, but of quantum mechanical origin, the source of quantum fluctuations in quantum phase transitions [3]. We observe a final superposition state of the two degenerate spin configurations for the ferromagnetic and the antiferromagnetic order, respectively. These correspond to deterministically entangled states achieved with a fidelity up to 88%. Our work demonstrates a building block for simulating quantum spin-Hamiltonians with trapped ions. The method has potential for scaling to a higher number of coupled spins [2].
Superradiant Quantum Heat Engine
Ali Ü. C. Hardal; Özgür E. Müstecapl?oglu
2015-04-22T23:59:59.000Z
Quantum physics revolutionized classical disciplines of mechanics, statistical physics, and electrodynamics. One branch of scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop efficient heat engines. Technology has a trend to miniaturize engines, reaching to quantum regimes. Development of quantum heat engines (QHEs) requires emerging field of quantum thermodynamics. Studies of QHEs debate whether quantum coherence can be used as a resource. We explore an alternative where it can function as an effective catalyst. We propose a QHE which consists of a photon gas inside an optical cavity as the working fluid and quantum coherent atomic clusters as the fuel. Utilizing the superradiance, where a cluster can radiate quadratically faster than a single atom, we show that the work output becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up QHE, our result is a fundamental difference of a quantum fuel from its classical counterpart.
Trajectories without quantum uncertainties
Eugene S. Polzik; Klemens Hammerer
2014-05-13T23:59:59.000Z
A common knowledge suggests that trajectories of particles in quantum mechanics always have quantum uncertainties. These quantum uncertainties set by the Heisenberg uncertainty principle limit precision of measurements of fields and forces, and ultimately give rise to the standard quantum limit in metrology. With the rapid developments of sensitivity of measurements these limits have been approached in various types of measurements including measurements of fields and acceleration. Here we show that a quantum trajectory of one system measured relatively to the other "reference system" with an effective negative mass can be quantum uncertainty--free. The method crucially relies on the generation of an Einstein-Podolsky-Rosen entangled state of two objects, one of which has an effective negative mass. From a practical perspective these ideas open the way towards force and acceleration measurements at new levels of sensitivity far below the standard quantum limit.
Quantum Field Theory and Representation Theory
Woit, Peter
Quantum Field Theory and Representation Theory Peter Woit woit@math.columbia.edu Department of Mathematics Columbia University Quantum Field Theory and Representation Theory p.1 #12;Outline of the talk · Quantum Mechanics and Representation Theory: Some History Quantum Field Theory and Representation Theory
Gravitomagnetism and Spinor Quantum Mechanics
Adler, Ronald J.; /Stanford U., HEPL /San Francisco State U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC; Varani, Elisa; /Unlisted; ,
2012-09-14T23:59:59.000Z
We give a systematic treatment of a spin 1=2 particle in a combined electromagnetic field and a weak gravitational field that is produced by a slowly moving matter source. This paper continues previous work on a spin zero particle, but it is largely self-contained and may serve as an introduction to spinors in a Riemann space. The analysis is based on the Dirac equation expressed in generally covariant form and coupled minimally to the electromagnetic field. The restriction to a slowly moving matter source, such as the earth, allows us to describe the gravitational field by a gravitoelectric (Newtonian) potential and a gravitomagnetic (frame-dragging) vector potential, the existence of which has recently been experimentally verified. Our main interest is the coupling of the orbital and spin angular momenta of the particle to the gravitomagnetic field. Specifically we calculate the gravitational gyromagnetic ratio as g{sub g} = 1 ; this is to be compared with the electromagnetic gyromagnetic ratio of g{sub e} = 2 for a Dirac electron.
Large scale quantum mechanical enzymology
Lever, Greg
2014-10-07T23:59:59.000Z
, during which many words of wisdom were imparted on me that I shall remember for a long time. Of course I can not forget my office mates who have always made TCM fun and interesting who, in chronological order, are Sam, Emma, Andrew, Daniel, Gen, Edgar...
Sergent, S. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Universite de Nice Sophia Antipolis, Parc Valrose, F-06102 Nice Cedex 2 (France); Damilano, B.; Huault, T.; Brault, J.; Tottereau, O.; Vennegues, P.; Leroux, M.; Semond, F.; Massies, J. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Korytov, M.
2011-03-01T23:59:59.000Z
The ammonia-based molecular beam epitaxy of GaN/(Al, Ga)N quantum dots is investigated using reflection high-energy electron diffraction, atomic force microscopy, transmission electron microscopy and photoluminescence. The main steps of the formation kinetics are identified and the influence of diffusion and evaporation processes on both the quantum dot and the wetting layer morphology is addressed. The correlation between the optical and structural properties of such structures finally allows for the analysis of matter exchanges between the quantum dots and the wetting layer during capping.
Superradiant Quantum Heat Engine
Ali Ü. C. Hardal; Özgür E. Müstecapl?oglu
2015-03-12T23:59:59.000Z
Quantum physics has revolutionized the classical disciplines of mechanics, statistical physics, and electrodynamics. It modernized our society with many advances such as lasers and transistors. One branch of scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop efficient heat engines. Technology has a trend to miniaturize engines, reaching to the quantum regimes. Inevitably, development of quantum heat engines (QHEs) requires investigations of thermodynamical principles from quantum mechanical perspective, and motivates the emerging field of quantum thermodynamics. Studies of QHEs debate on whether quantum coherence can be used as a resource. We explore an alternative that quantum coherence can be a catalyst. We propose a QHE which consists of a photon gas inside an optical cavity as the working fluid and quantum coherent atomic clusters as the fuel. Utilizing the superradiance, where a cluster can radiate quadratically faster than a single atom, we show that the work capability of the QHE becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up a QHE, our results reveal a fundamental difference of a quantum fuel from its classical counterpart.
Bandyopadhyay, Antar
BOOK REVIEWS Gerald McGrath Land Law Reform in Eastern Africa: Traditional or Transformative of 50 years of land law reform in Eastern Africa, shows that some of them, especially Kenya and Tanzania to an examination of the land reform legislation that was been enacted by each jurisdiction after its independ- ence
07-NIF Dedication: Jerry McNerney
Congressman Jerry McNerney
2010-09-01T23:59:59.000Z
The National Ignition Facility, the world's largest laser system, was dedicated at a ceremony on May 29, 2009 at Lawrence Livermore National Laboratory. These are the remarks by Congressman Jerry McNerney, of California's 11th district, which adjoins Livermore.
The McDonald-Mehta Lecture Series
Zhuang, Yu
Challenges for Floating Offshore Wind Turbines Dr. Andrew Kennedy Dr. Jason Jonkman Associate ProfessorThe McDonald-Mehta Lecture Series Fall 2014 National Wind Institute Texas Tech University www.nwi.ttu.edu P.O.Box43155 Lubbock,Texas79409-3155 www.nwi.ttu.edu The National Wind Institute (NWI) at Texas Tech
Virginia Tech
, they approached Virginia Tech for help with research and development. Some background: When Hurricane Andrew made as hurricane season approaches. Two Virginia Tech alumni and brothers Chuck and Pat Johnson are principals and Andrew McCoy of the Department of Building Construction. The first phase consisted of a study of airflow
Broader source: Energy.gov [DOE]
Mr. McConnell is the Deputy Associate Administrator for Infrastructure and Operations. He is responsible for operations, infrastructure, capital planning, environmental programs and packaging and transportation for the NNSA National Security Enterprise as well as management and oversight of NNSA's seven field offices.
Fault-tolerant quantum computation
Shor, P W
1996-01-01T23:59:59.000Z
Recently, it was realized that use of the properties of quantum mechanics might speed up certain computations dramatically. Interest in quantum computation has since been growing. One of the main difficulties of realizing quantum computation is that decoherence tends to destroy the information in a superposition of states in a quantum computer, thus making long computations impossible. A futher difficulty is that inaccuracies in quantum state transformations throughout the computation accumulate, rendering the output of long computations unreliable. It was previously known that a quantum circuit with t gates could tolerate O(1/t) amounts of inaccuracy and decoherence per gate. We show, for any quantum computation with t gates, how to build a polynomial size quantum circuit that can tolerate O(1/(log t)^c) amounts of inaccuracy and decoherence per gate, for some constant c. We do this by showing how to compute using quantum error correcting codes. These codes were previously known to provide resistance to erro...
Depletion calculations for the McClellan Nuclear Radiation Center.
Klann, Raymond T.; Newell, Daniel L.
1997-01-01T23:59:59.000Z
FOR THE MCCLELLAN RADIATION CENTER NUCLEAR BY Raymond T.for the McClellan Nuclear Radiation Center Raymond T. KkmnL. Newell McClellan Nuclear Radiation Center SM-ALC/TIR 5335
Virendra Singh
2005-10-24T23:59:59.000Z
We review here the main contributions of Einstein to the quantum theory. To put them in perspective we first give an account of Physics as it was before him. It is followed by a brief account of the problem of black body radiation which provided the context for Planck to introduce the idea of quantum. Einstein's revolutionary paper of 1905 on light-quantum hypothesis is then described as well as an application of this idea to the photoelectric effect. We next take up a discussion of Einstein's other contributions to old quantum theory. These include (i) his theory of specific heat of solids, which was the first application of quantum theory to matter, (ii) his discovery of wave-particle duality for light and (iii) Einstein's A and B coefficients relating to the probabilities of emission and absorption of light by atomic systems and his discovery of radiation stimulated emission of light which provides the basis for laser action. We then describe Einstein's contribution to quantum statistics viz Bose-Einstein Statistics and his prediction of Bose-Einstein condensation of a boson gas. Einstein played a pivotal role in the discovery of Quantum mechanics and this is briefly mentioned. After 1925 Einstein's contributed mainly to the foundations of Quantum Mechanics. We choose to discuss here (i) his Ensemble (or Statistical) Interpretation of Quantum Mechanics and (ii) the discovery of Einstein-Podolsky-Rosen (EPR) correlations and the EPR theorem on the conflict between Einstein-Locality and the completeness of the formalism of Quantum Mechanics. We end with some comments on later developments.
Quantum Transport in Misoriented Layers of Graphene: Physics and Device Applications
Habib, K M Masum
2013-01-01T23:59:59.000Z
calculation of electronic structures are performed with the ab initio quantum mechanical molecular dynamics,
Prudaev, I. A., E-mail: jaia@pochta.ru; Golygin, I. Yu.; Shirapov, S. B.; Romanov, I. S.; Khludkov, S. S.; Tolbanov, O. P. [Tomsk State University (Russian Federation)] [Tomsk State University (Russian Federation)
2013-10-15T23:59:59.000Z
The experimental current-voltage characteristics and dependences of the external quantum yield on the current density of light-emitting diodes based on InGaN/GaN multiple quantum wells for the wide temperature range T = 10-400 K are presented. It is shown that, at low-temperatures T < 100 K, the injection of holes into the quantum wells occurs from localized acceptor states. The low-temperature injection of electrons into p-GaN occurs due to quasi-ballistic transport in the region of multiple quantum wells. An increase in temperature leads to an increase in the current which is governed by thermally activated hole and electron injection from the allowed bands of GaN.
Washington and Lee University Andrew W. McThenia, Jr.
Marsh, David
at the Federal Prison in Alderson, W.Va., and with `black lung' victims in southern West Virginia. Professor Mc
Jeremy L. O'Brien; Akira Furusawa; Jelena Vu?kovi?
2010-03-20T23:59:59.000Z
The first quantum technology, which harnesses uniquely quantum mechanical effects for its core operation, has arrived in the form of commercially available quantum key distribution systems that achieve enhanced security by encoding information in photons such that information gained by an eavesdropper can be detected. Anticipated future quantum technologies include large-scale secure networks, enhanced measurement and lithography, and quantum information processors, promising exponentially greater computation power for particular tasks. Photonics is destined for a central role in such technologies owing to the need for high-speed transmission and the outstanding low-noise properties of photons. These technologies may use single photons or quantum states of bright laser beams, or both, and will undoubtably apply and drive state-of-the-art developments in photonics.
Updated 6-12 Donald F. McCormack
and an annual budget of over $1B. Effective April 4, 2012, Mr. McCormack assumed additional duties as Acting. From September 2001 until May 2002, Mr. McCormack was Director for Weapon Systems, responsible, and complete life cycle support for undersea weapon systems. During his career, Mr. McCormack has been
ARCHITECTURE AT McGILL Bachelor of Science in Architecture
Barthelat, Francois
ARCHITECTURE AT McGILL Bachelor of Science in Architecture What is architecture? Architecture. Is this the program for me? Architecture students come to McGill with a wide variety of backgrounds and life? You will need a professional degree in architecture in order to practice as an architect. At Mc
Sears, T.; Lammert, M.; Colby, K.; Walter, R.
2014-09-01T23:59:59.000Z
This report examines the performance of two electric vehicles (EVs) at McMurdo, Antarctica (McMurdo). The study examined the performance of two e-ride Industries EVs initially delivered to McMurdo on February 16, 2011, and compared their performance and fuel use with that of conventional vehicles that have a duty cycle similar to that of the EVs used at McMurdo.
Some Studies in Noncommutative Quantum Field Theories
Sunandan Gangopadhyay
2008-06-12T23:59:59.000Z
The central theme of this thesis is to study some aspects of noncommutative quantum mechanics and noncommutative quantum field theory. We explore how noncommutative structures can emerge and study the consequences of such structures in various physical models.
Quantum Equivalence and Quantum Signatures in Heat Engines
Raam Uzdin; Amikam Levy; Ronnie Kosloff
2015-04-15T23:59:59.000Z
Quantum heat engines (QHE) are thermal machines where the working substance is quantum. In the extreme case the working medium can be a single particle or a few level quantum system. The study of QHE has shown a remarkable similarity with the standard thermodynamical models, thus raising the issue what is quantum in quantum thermodynamics. Our main result is thermodynamical equivalence of all engine type in the quantum regime of small action. They have the same power, the same heat, the same efficiency, and they even have the same relaxation rates and relaxation modes. Furthermore, it is shown that QHE have quantum-thermodynamic signature, i.e thermodynamic measurements can confirm the presence of quantum coherence in the device. The coherent work extraction mechanism enables power outputs that greatly exceed the power of stochastic (dephased) engines.
Minimal Self-Contained Quantum Refrigeration Machine Based on Four Quantum Dots
Davide Venturelli; Rosario Fazio; Vittorio Giovannetti
2013-06-22T23:59:59.000Z
We present a theoretical study of an electronic quantum refrigerator based on four quantum dots arranged in a square configuration, in contact with as many thermal reservoirs. We show that the system implements the basic minimal mechanism for acting as a self-contained quantum refrigerator, by demonstrating heat extraction from the coldest reservoir and the cooling of the nearby quantum-dot.
The MC21 Monte Carlo Transport Code
Sutton TM, Donovan TJ, Trumbull TH, Dobreff PS, Caro E, Griesheimer DP, Tyburski LJ, Carpenter DC, Joo H
2007-01-09T23:59:59.000Z
MC21 is a new Monte Carlo neutron and photon transport code currently under joint development at the Knolls Atomic Power Laboratory and the Bettis Atomic Power Laboratory. MC21 is the Monte Carlo transport kernel of the broader Common Monte Carlo Design Tool (CMCDT), which is also currently under development. The vision for CMCDT is to provide an automated, computer-aided modeling and post-processing environment integrated with a Monte Carlo solver that is optimized for reactor analysis. CMCDT represents a strategy to push the Monte Carlo method beyond its traditional role as a benchmarking tool or ''tool of last resort'' and into a dominant design role. This paper describes various aspects of the code, including the neutron physics and nuclear data treatments, the geometry representation, and the tally and depletion capabilities.
McGILL UNIVERSITY BIKE RACK INVENTORY
Kambhampati, Patanjali
McGILL UNIVERSITY BIKE RACK INVENTORY DOWNTOWN CAMPUS 09.2012 #12;McGILL UNIVERSITY BIKE RACK INVENTORY MAP DOWNTOWN CAMPUS 2012 4xA-8 4xA-8 6xA-8, 4xC-11 1xC-11 5xA-8 1xA-8 1xA-8 4xA-8 2xA-8 3xA-8 1x RACK INVENTORY MAP - ZONE A DOWNTOWN CAMPUS 2012 #12;32 32 6xA-8, 4xC-11 11 40 8 1xA-8 32 16 24 1xG-8
Coherent states in the quantum multiverse
S. Robles-Perez; Y. Hassouni; P. F. Gonzalez-Diaz
2009-11-24T23:59:59.000Z
In this paper, we study the role of coherent states in the realm of quantum cosmology, both in a second-quantized single universe and in a third-quantized quantum multiverse. In particular, most emphasis will be paid to the quantum description of multiverses made up of accelerated universes. We have shown that the quantum states involved at a quantum mechanical multiverse whose single universes are accelerated are given by squeezed states having no classical analogs.
QER- Comment of Annie McCollum
Broader source: Energy.gov [DOE]
I urge you to take seriously scientific and community concerns about fracked gas and subsidizing infrastructure that supports its distribution. It is imperative that we fully fund efforts to build infrastructure and capacity for sustainable energy, not for more fossil fuels. The proposed pipeline expansion in New York and Massachusetts is short-sighted, unnecessary, and a step in the wrong direction. There are better ways to meet our energy needs. Annie McCollum
North Carolina Nuclear Profile - McGuire
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthrough 1996)McGuire" "Unit","Summer capacity
Physical process Mechanical mechanisms
Berlin,Technische Universität
1 Physical process Generation · Mechanical mechanisms F = m·a · Electric/Magnetic mechanisms F = B·i·l · Fluid dynamic/Hydraulic mechanisms q, p, ij · Thermal/Optical #12;2 Source unit
Sibley School of Mechanical and Aerospace Engineering
Bonassar, Larry
design; sustainable design; additive manufacturing; manufacturing of advanced and multifunctional 607 255-0813 mc288@cornell.edu October 2014 Faculty Position in Design and Manufacturing Mechanical and Manufacturing, as related strongly to the disciplines within Mechanical and Aerospace Engineering. Candidates
Rau, A.R.P. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Inokuti, M. [Argonne National Lab., IL (United States). Physics Div.
1997-08-01T23:59:59.000Z
The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term quantum defect does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schroedinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. The authors present the early history of the quantum-defect idea, and sketch its recent developments.
Smith, Roy
graduation from U.S.C. with a degree in Civil Engineering, Marvin began his career as a builder. Mr. Mac, starting with Uncle Sterling Graydon at Edisto Beach and concluding with Joe Dixon at DeBordieu Beach), Marty McCrory (Lana), Clint Wallace (Jenna), Nick and Lewis Wallace, Alex and Sterling McCrory, D
Intrinsic Time Quantum Geometrodynamics
Eyo Eyo Ita III; Chopin Soo; Hoi-Lai Yu
2015-02-06T23:59:59.000Z
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
Intrinsic Time Quantum Geometrodynamics
Ita, Eyo Eyo; Yu, Hoi-Lai
2015-01-01T23:59:59.000Z
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental canonical commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
Yasunori Nomura
2012-05-26T23:59:59.000Z
We consider the multiverse in the intrinsically quantum mechanical framework recently proposed in Refs. [1,2]. By requiring that the principles of quantum mechanics are universally valid and that physical predictions do not depend on the reference frame one chooses to describe the multiverse, we find that the multiverse state must be static---in particular, the multiverse does not have a beginning or end. We argue that, despite its naive appearance, this does not contradict observation, including the fact that we observe that time flows in a definite direction. Selecting the multiverse state is ultimately boiled down to finding normalizable solutions to certain zero-eigenvalue equations, analogous to the case of the hydrogen atom. Unambiguous physical predictions would then follow, according to the rules of quantum mechanics.
Crystal McDonald | Department of Energy
Office of Environmental Management (EM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T, Inc.'sEnergyTexas1.SpaceFluorControlsEnergyRev. 1)Crystal McDonald About
Bill McMillan | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
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Faces of Science: Nate McDowell
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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NREL: Energy Analysis - Colin McMillan
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Saleshttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifNRELPower Systems EngineeringSigrinColin A. McMillan
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Faces of Science: Nate McDowell
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) Environmental Assessments (EA)Budget Â» FY 2014 BudgetNate McDowell Faces of Science:
O. V. Veko; K. V. Kazmerchuk; E. M. Ovsiyuk; V. V. Kisel; V. M. Red'kov
2014-11-07T23:59:59.000Z
Relativistic theory of the Cox's scalar not point-like particle with intrinsic structure is developed on the background of arbitrary curved space-time. It is shown that in the most general form, the extended Proca-like tensor first order system of equations contains non minimal interaction terms through electromagnetic tensor F_{\\alpha \\beta} and Ricci tensor R_{\\alpha \\beta}. In relativistic Cox's theory, the limiting procedure to non-relativistic approximation is performed in a special class of curved space-time models. This theory is specified in simple geometrical backgrounds: Euclid's, Lobachevsky's, and Rie\\-mann's. Wave equation for the Cox's particle is solved exactly in presence of external uniform magnetic and electric fields in the case of Minkowski space. Non-trivial additional structure of the particle modifies the frequency of a quantum oscillator arising effectively in presence if external magnetic field. Extension of these problems to the case of the hyperbolic Lobachevsky space is examined. In presence of the magnetic field, the quantum problem in radial variable has been solved exactly; the quantum motion in z-direction is described by 1-dimensional Schr\\"{o}dinger-like equation in an effective potential which turns out to be too difficult for analytical treatment. In the presence of electric field, the situation is similar. The same analysis has been performed for spherical Riemann space model.
Stapp, Henry
2011-11-10T23:59:59.000Z
Robert Griffiths has recently addressed, within the framework of a ‘consistent quantum theory’ (CQT) that he has developed, the issue of whether, as is often claimed, quantum mechanics entails a need for faster-than-light transfers of information over long distances. He argues, on the basis of his examination of certain arguments that claim to demonstrate the existence of such nonlocal influences, that such influences do not exist. However, his examination was restricted mainly to hidden-variable-based arguments that include in their premises some essentially classical-physics-type assumptions that are fundamentally incompatible with the precepts of quantum physics. One cannot logically prove properties of a system by attributing to the system properties alien to that system. Hence Griffiths’ rejection of hidden-variable-based proofs is logically warranted. Griffiths mentions the existence of a certain alternative proof that does not involve hidden variables, and that uses only macroscopically described observable properties. He notes that he had examined in his book proofs of this general kind, and concluded that they provide no evidence for nonlocal influences. But he did not examine the particular proof that he cites. An examination of that particular proof by the method specified by his ‘consistent quantum theory’ shows that the cited proof is valid within that restrictive framework. This necessary existence, within the ‘consistent’ framework, of long range essentially instantaneous influences refutes the claim made by Griffiths that his ‘consistent’ framework is superior to the orthodox quantum theory of von Neumann because it does not entail instantaneous influences. An added section responds to Griffiths’ reply, which cites a litany of ambiguities that seem to restrict, devastatingly, the scope of his CQT formalism, apparently to buttress his claim that my use of that formalism to validate the nonlocality theorem is flawed. But the vagaries that he cites do not upset the proof in question. It is show here in detail why the precise statement of this theorem justifies the specified application of CQT. It is also shown, in response to his challenge, why a putative proof of locality that he has proposed is not valid.
2012 McQuay International 1 2012 McQuay International SmartSourceTM
Compressor 3 and 4 ton cooling capacities Â does 1 - 5 tons. Features ECM variable speed fan motor Choice compressor provides capacity that is continually adjusted up or down to changing heat or cool loads. Adjusts for Improved Part Load Performance #12;Â© 2012 McQuay International 9 Compressor Modulates = Precise Room Temp
McMinnville Water & Light- Conservation Service Loan Program
Broader source: Energy.gov [DOE]
McMinnville Water & Light offers financing to residential and commercial customers to make energy efficient improvements to eligible facilities and homes. Financing is available for pre...
David Ben McReynolds: home - West Lafayette
David Ben McReynolds. PhD: University of Texas, Austin 2006; Title: Assistant Professor of Mathematics; Research Interests: geometry, topology, geometric ...
McKees Rocks, Pennsylvania: Energy Resources | Open Energy Information
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McKinleyville, California: Energy Resources | Open Energy Information
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McKinsey Carbon Supply Curves | Open Energy Information
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Noncommutative Quantum Field Theories
H. O. Girotti
2003-03-19T23:59:59.000Z
We start by reviewing the formulation of noncommutative quantum mechanics as a constrained system. Then, we address to the problem of field theories defined on a noncommutative space-time manifold. The Moyal product is introduced and the appearance of the UV/IR mechanism is exemplified. The emphasis is on finding and analyzing noncommutative quantum field theories which are renormalizable and free of nonintegrable infrared singularities. In this last connection we give a detailed discussion of the quantization of the noncommutative Wess-Zumino model as well as of its low energy behavior.
Quantum Plasma Model with Hydrodynamical Phase Transition
Introduction The quantum Jellium model is a system of electrons, interacting via Coulomb forces both with one of Fourier's law of heat conduction for a certain model of interacting atoms, the passage from quantum. The object of the present article is to provide a further quantum mechanical treatment of * Partially
On quantum theories of the mind
Henry P. Stapp
1997-11-26T23:59:59.000Z
Replies are given to arguments advanced in this journal that claim to show that it is to nonlinear classical mechanics rather than quantum mechanics that one must look for the physical underpinnings of consciousness.
Shoubridge, Eric
Code of Conduct for Users of McGill Computing Facilities McGill Computing Facilities (MCF for Users of McGill Computing Facilities 1 #12;Code of Conduct for Users of McGill Computing Facilities) are intended to support the academic mission and the administrative functions of the University. This code
McMaster University | Department of Anesthesia Citywide Rounds
Thompson, Michael
McMaster University | Department of Anesthesia Citywide Rounds Dr. David Sussman PGY-3 Resident Department of Anesthesia, McMaster University "A World without Propofol: Looking Beyond Western Medicine A Glimpse into the World of Anesthesia in Uganda" Objectives: 1) Review brief history of Uganda including
Looking into Higher Dimensions: Research with Joseph McMoneagle
Bryan, Ronald
by nuclear reactors can travel as far as 25 light- years in solid lead before being deflected. Another at nuclear distances, and see into higher dimensions. To "calibrate" McMoneagle, I asked him three things (in, if not the best: Joseph McMoneagle. [Joe has published four interesting and informative books on remote viewing
Communication Disorders David L. McPherson, Chair
Hart, Gus
Communication Disorders David L. McPherson, Chair 136 TLRB, (801) 422-4318 David O. McKay School The degree program in the Department of Communication Disorders is open enrollment. Graduation Requirements.0 Undergraduate Programs and Degrees BS Communication Disorders Minor Communication Disorders Students should see
Light Higgses and Dark Matter Bob McElrath
California at Santa Cruz, University of
Light Higgses and Dark Matter Bob McElrath University of California, Davis Santa Cruz, February 26, 2007 #12;Light Low-Mass Dark Matter Bob McElrath University of California, Davis ICHEP, January 2, 2007 and Expectations for Light Dark Matter · Invisible Quarkonium Decays · Light Dark Matter from SUSY · Detection
Scheme Evolution and the Relational Algebra Edwin McKenzie*
North Carolina at Chapel Hill, University of
Scheme Evolution and the Relational Algebra TR87-003 Revised May 1988 Edwin McKenzie* Richard Institution. #12;Scheme Evolution and the Relational Algebra Edwin McKenzie and Richard Snodgrass Department, evolution of a database's contents and evolution of a database's scheme. We define a relation's scheme
Quantum realism and quantum surrealism
Mateus Araújo
2014-08-29T23:59:59.000Z
In this thesis we explore the questions of what should be considered a "classical" theory, and which aspects of quantum theory cannot be captured by any theory that respects our intuition of classicality. This exploration is divided in two parts: in the first we review classical results of the literature, such as the Kochen-Specker theorem, von Neumann's theorem, Gleason's theorem, as well as more recent ideas, such as the distinction between $\\psi$-ontic and $\\psi$-epistemic ontological models, Spekkens' definition of contextuality, Hardy's ontological excess baggage theorem and the PBR theorem. The second part is concerned with pinning down what should be the "correct" definition of contextuality. We settle down on the definition advocated by Abramsky and Branderburger, motivated by the Fine theorem, and show the connection of this definition with the work of George Boole. This definition allows us to unify the notions of locality and noncontextuality, and use largely the same tools to characterize how quantum mechanics violates these notions of classicality. Exploring this formalism, we find a new family of noncontextuality inequalities. We conclude by reviewing the notion of state-independent contextuality.
Quantum Information Science and Nanotechnology
Alexander Yu. Vlasov
2009-03-06T23:59:59.000Z
In this note is touched upon an application of quantum information science (QIS) in nanotechnology area. The laws of quantum mechanics may be very important for nano-scale objects. A problem with simulating of quantum systems is well known and quantum computer was initially suggested by R. Feynman just as the way to overcome such difficulties. Mathematical methods developed in QIS also may be applied for description of nano-devices. Few illustrative examples are mentioned and they may be related with so-called fourth generation of nanotechnology products.
P. Falsaperla; G. Fonte; G. Salesi
2007-01-16T23:59:59.000Z
We show that it is possible to associate univocally with each given solution of the time-dependent Schroedinger equation a particular phase flow ("quantum flow") of a non-autonomous dynamical system. This fact allows us to introduce a definition of chaos in quantum dynamics (quantum chaos), which is based on the classical theory of chaos in dynamical systems. In such a way we can introduce quantities which may be appelled "Quantum Lyapunov Exponents". Our approach applies to a non-relativistic quantum-mechanical system of n charged particles; in the present work numerical calculations are performed only for the hydrogen atom. In the computation of the trajectories we first neglect the spin contribution to chaos, then we consider the spin effects in quantum chaos. We show how the quantum Lyapunov exponents can be evaluated and give several numerical results which describe some properties found in the present approach. Although the system is very simple and the classical counterpart is regular, the most non-stationary solutions of the corresponding Schroeodinger equation are "chaotic" according to our definition.
Reactor control system upgrade for the McClellan Nuclear Radiation Center
Power, Michael A.
1999-01-01T23:59:59.000Z
FOR THE McCLELLAN NUCLEAR RADIATION CENTER SACRAMENTO, CA Byfor the McClellan Nuclear Radiation Center Sacramento, CAfor the McClellan Nuclear Radiation Facility. This new
McGill Cancer NutritionRehabilitation Program Annual Report 2009 AAPPPPEENNDDIIXX II
Barthelat, Francois
McGill Cancer NutritionRehabilitation Program Annual Report 2009 AAPPPPEENNDDIIXX II CCLLIINNIICCAALL AACCTTIIVVIITTYY McGill Cancer NutritionRehabilitation Program Statistics for January;McGill Cancer NutritionRehabilitation Program Annual Report 2009 AAPPPPEENNDDIIXX IIII
An investigation of precision and scaling issues in nuclear spin and trapped-ion quantum simulators
Clark, Robert J., Ph. D. Massachusetts Institute of Technology
2009-01-01T23:59:59.000Z
Quantum simulation offers the possibility of using a controllable quantum-mechanical system to implement the dynamics of another quantum system, performing calculations that are intractable on classical computers for all ...
Tunable quantum beam splitters for coherent manipulation of a solid-state tripartite qubit system
Sun, Guozhu; Wen, Xueda; Mao, Bo; Chen, Jian; Yu, Yang; Wu, Peiheng; Han, Siyuan
2010-08-10T23:59:59.000Z
Coherent control of quantum states is at the heart of implementing solid-state quantum processors and testing quantum mechanics at the macroscopic level. Despite significant progress made in recent years in controlling ...
Integrated chips and optical cavities for trapped ion quantum information processing
Leibrandt, David R
2009-01-01T23:59:59.000Z
Quantum information processing is a new and exciting field which uses quantum mechanical systems to perform information processing. At the heart of the excitement are quantum computation - which promises efficient algorithms ...
Undergraduate Lecture Notes in Topological Quantum Field Theory
Vladimir G. Ivancevic; Tijana T. Ivancevic
2008-12-11T23:59:59.000Z
These third-year lecture notes are designed for a 1-semester course in topological quantum field theory (TQFT). Assumed background in mathematics and physics are only standard second-year subjects: multivariable calculus, introduction to quantum mechanics and basic electromagnetism. Keywords: quantum mechanics/field theory, path integral, Hodge decomposition, Chern-Simons and Yang-Mills gauge theories, conformal field theory
Graphical user interfaces for the McCellan Nuclear Radiation Center (MNRC)
Brown-VanHoozer, S. A.; Power, Mike; Forsmann, Hope
1998-01-01T23:59:59.000Z
Interfaces for McClellan Nuclear Radiation Center S. AlenkaAbstract McClellan’s Nuclear Radiation Center (MNRC) control
Preprocessing of backprojection images in the McClellan Nuclear Radiation Center tomography system
Gibbons, Matthew R.; Shields, Kevin
1998-01-01T23:59:59.000Z
Images in the McClellan Nuclear Radiation Center TomographyBays,” McClellan Nuclear Radiation Center report MNRC-0057-
MC&A System Effectiveness Tool (MSET) (Presentation 2)
Powell, Danny H [ORNL] [ORNL; Elwood Jr, Robert H [ORNL] [ORNL
2011-01-01T23:59:59.000Z
MSET is a self-assessment or inspection tool utilizing probabilistic risk assessment (PRA) methodology to calculate the system effectiveness of a nuclear facility's material control and accountability (MC&A) system. MSET analyzes the effectiveness of an MC&A system based on defined performance metrics for MC&A functions defined based on U.S. and international best practices and regulations. MSET analysis is based on performance of the entire MC&A system including defense-in-depth attributes and sensitivity analysis of changes in the system, both positive and negative. MSET analysis considers: accounting; containment; access control; surveillance capabilities of the system; and other interfaces with the physical protection systems that provide detection of an unauthorized action. MSET performs a system effectiveness calculation evaluation against a defined performance metric. MSET uses PRA techniques to analyze the MC&A system. MSET is a tool for evaluating the system effectiveness of MC&A systems during self-assessment or external inspection. MSET has been developed, tested, and benchmarked by the U.S. DOE. In collaboration with the U.S. DOE, Rosatom is developing a Russian version (MSET-R) planned for pilot implementation at select material balance areas in 2011. MSET has been shown to be an effective training and communication tool for MC&A.
Semiclassical analysis of quantum dynamics
Siyang Yang
2011-11-15T23:59:59.000Z
Simulating the molecular dynamics (MD) using classical or semi-classical trajectories provides important details for the understanding of many chemical reactions, protein folding, drug design, and solvation effects. MD simulations using trajectories have achieved great successes in the computer simulations of various systems, but it is difficult to incorporate quantum effects in a robust way. Therefore, improving quantum wavepacket dynamics and incorporating nonadiabatic transitions and quantum effects into classical and semi-classical molecular dynamics is critical as well as challenging. In this paper, we present a MD scheme in which a new set of equations of motion (EOM) are proposed to effectively propagate nuclear trajectories while conserving quantum mechanical energy which is critical for describing quantum effects like tunneling. The new quantum EOM is tested on a one-state one-dimensional and a two-state two-dimensional model nonadiabatic systems. The global quantum force experienced by each trajectory promotes energy redistribution among the bundle of trajectories, and thus helps the individual trajectory tunnel through the potential barrier higher than the energy of the trajectory itself. Construction of the new quantum force and EOM also provides a better way to treat the issue of back-reaction in mixed quantum-classical (MQC) methods, i.e. self-consistency between quantum degrees of freedom (DOF) and classical DOF.
Fault-tolerant quantum computation
Peter W. Shor
1997-03-05T23:59:59.000Z
Recently, it was realized that use of the properties of quantum mechanics might speed up certain computations dramatically. Interest in quantum computation has since been growing. One of the main difficulties of realizing quantum computation is that decoherence tends to destroy the information in a superposition of states in a quantum computer, thus making long computations impossible. A futher difficulty is that inaccuracies in quantum state transformations throughout the computation accumulate, rendering the output of long computations unreliable. It was previously known that a quantum circuit with t gates could tolerate O(1/t) amounts of inaccuracy and decoherence per gate. We show, for any quantum computation with t gates, how to build a polynomial size quantum circuit that can tolerate O(1/(log t)^c) amounts of inaccuracy and decoherence per gate, for some constant c. We do this by showing how to compute using quantum error correcting codes. These codes were previously known to provide resistance to errors while storing and transmitting quantum data.
Acrolein-Mediated Mechanisms of Neuronal Death
Shi, Riyi
Acrolein-Mediated Mechanisms of Neuronal Death Peishan Liu-Snyder,1 Helen McNally,1 Riyi Shi,1 stress lead to breakdown of membrane lipids (lipid peroxidation) during secondary injury. Acrolein certain fea- tures of cell death induced by acrolein on PC12 cells as well as cells from dorsal root
A general-purpose pulse sequencer for quantum computing
Pháº¡m, Paul Tân Tháº¿
2005-01-01T23:59:59.000Z
Quantum mechanics presents a more general and potentially more powerful model of computation than classical systems. Quantum bits have many physically different representations which nonetheless share a common need for ...
Ultrafast sources of entangled photons for quantum information processing
Kuzucu, Oktay Onur, 1980-
2008-01-01T23:59:59.000Z
Recent advances in quantum information processing (QIP) have enabled practical applications of quantum mechanics in various fields such as cryptography, computation, and metrology. Most of these applications use photons ...
8.05 Quantum Physics II, Fall 2002
Rajagopal, Krishna, 1965-
Together 8.05 and 8.06 cover quantum physics with applications drawn from modern physics. General formalism of quantum mechanics: states, operators, Dirac notation, representations, measurement theory. Harmonic oscillator: ...
McNary-John Day | Open Energy Information
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McDuffie County, Georgia: Energy Resources | Open Energy Information
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McGinness Hills Geothermal Project | Open Energy Information
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McGrath, Alaska: Energy Resources | Open Energy Information
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McGrath, Minnesota: Energy Resources | Open Energy Information
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McGrew, Nebraska: Energy Resources | Open Energy Information
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McKay Bay Facility Biomass Facility | Open Energy Information
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McKean County, Pennsylvania: Energy Resources | Open Energy Information
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McKeesport, Pennsylvania: Energy Resources | Open Energy Information
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McKinley, Minnesota: Energy Resources | Open Energy Information
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McNairy County, Tennessee: Energy Resources | Open Energy Information
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Functional quantum biology in photosynthesis and magnetoreception
Lambert, Neill; Cheng, Yuan-Chung; Li, Che-Ming; Chen, Guang-Yin; Nori, Franco
2012-01-01T23:59:59.000Z
Is there a functional role for quantum mechanics or coherent quantum effects in biological processes? While this question is as old as quantum theory, only recently have measurements on biological systems on ultra-fast time-scales shed light on a possible answer. In this review we give an overview of the two main candidates for biological systems which may harness such functional quantum effects: photosynthesis and magnetoreception. We discuss some of the latest evidence both for and against room temperature quantum coherence, and consider whether there is truly a functional role for coherence in these biological mechanisms. Finally, we give a brief overview of some more speculative examples of functional quantum biology including the sense of smell, long-range quantum tunneling in proteins, biological photoreceptors, and the flow of ions across a cell membrane.
Functional quantum biology in photosynthesis and magnetoreception
Neill Lambert; Yueh-Nan Chen; Yuan-Chung Cheng; Che-Ming Li; Guang-Yin Chen; Franco Nori
2012-05-04T23:59:59.000Z
Is there a functional role for quantum mechanics or coherent quantum effects in biological processes? While this question is as old as quantum theory, only recently have measurements on biological systems on ultra-fast time-scales shed light on a possible answer. In this review we give an overview of the two main candidates for biological systems which may harness such functional quantum effects: photosynthesis and magnetoreception. We discuss some of the latest evidence both for and against room temperature quantum coherence, and consider whether there is truly a functional role for coherence in these biological mechanisms. Finally, we give a brief overview of some more speculative examples of functional quantum biology including the sense of smell, long-range quantum tunneling in proteins, biological photoreceptors, and the flow of ions across a cell membrane.
Quantum correlations; quantum probability approach
W. A. Majewski
2015-05-21T23:59:59.000Z
This survey gives a comprehensive account of quantum correlations understood as a phenomenon stemming from the rules of quantization. Centered on quantum probability it describes the physical concepts related to correlations (both classical and quantum), mathematical structures, and their consequences. These include the canonical form of classical correlation functionals, general definitions of separable (entangled) states, definition and analysis of quantumness of correlations, description of entanglement of formation, and PPT states. This work is intended both for physicists interested not only in collection of results but also in the mathematical methods justifying them, and mathematicians looking for an application of quantum probability to concrete new problems of quantum theory.
Zurek, Wojciech H [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
Quantum Darwinism - proliferation, in the environment, of multiple records of selected states of the system (its information-theoretic progeny) - explains how quantum fragility of individual state can lead to classical robustness of their multitude.
G. Manfredi
2005-05-01T23:59:59.000Z
Traditional plasma physics has mainly focused on regimes characterized by high temperatures and low densities, for which quantum-mechanical effects have virtually no impact. However, recent technological advances (particularly on miniaturized semiconductor devices and nanoscale objects) have made it possible to envisage practical applications of plasma physics where the quantum nature of the particles plays a crucial role. Here, I shall review different approaches to the modeling of quantum effects in electrostatic collisionless plasmas. The full kinetic model is provided by the Wigner equation, which is the quantum analog of the Vlasov equation. The Wigner formalism is particularly attractive, as it recasts quantum mechanics in the familiar classical phase space, although this comes at the cost of dealing with negative distribution functions. Equivalently, the Wigner model can be expressed in terms of $N$ one-particle Schr{\\"o}dinger equations, coupled by Poisson's equation: this is the Hartree formalism, which is related to the `multi-stream' approach of classical plasma physics. In order to reduce the complexity of the above approaches, it is possible to develop a quantum fluid model by taking velocity-space moments of the Wigner equation. Finally, certain regimes at large excitation energies can be described by semiclassical kinetic models (Vlasov-Poisson), provided that the initial ground-state equilibrium is treated quantum-mechanically. The above models are validated and compared both in the linear and nonlinear regimes.
Quantum Cloning Machines and the Applications
Heng Fan; Yi-Nan Wang; Li Jing; Jie-Dong Yue; Han-Duo Shi; Yong-Liang Zhang; Liang-Zhu Mu
2014-08-02T23:59:59.000Z
No-cloning theorem is fundamental for quantum mechanics and for quantum information science that states an unknown quantum state cannot be cloned perfectly. However, we can try to clone a quantum state approximately with the optimal fidelity, or instead, we can try to clone it perfectly with the largest probability. Thus various quantum cloning machines have been designed for different quantum information protocols. Specifically, quantum cloning machines can be designed to analyze the security of quantum key distribution protocols such as BB84 protocol, six-state protocol, B92 protocol and their generalizations. Some well-known quantum cloning machines include universal quantum cloning machine, phase-covariant cloning machine, the asymmetric quantum cloning machine and the probabilistic quantum cloning machine etc. In the past years, much progress has been made in studying quantum cloning machines and their applications and implementations, both theoretically and experimentally. In this review, we will give a complete description of those important developments about quantum cloning and some related topics. On the other hand, this review is self-consistent, and in particular, we try to present some detailed formulations so that further study can be taken based on those results.
Quantum thermodynamic cooling cycle
Jose P. Palao; Ronnie Kosloff; Jeffrey M. Gordon
2001-06-08T23:59:59.000Z
The quantum-mechanical and thermodynamic properties of a 3-level molecular cooling cycle are derived. An inadequacy of earlier models is rectified in accounting for the spontaneous emission and absorption associated with the coupling to the coherent driving field via an environmental reservoir. This additional coupling need not be dissipative, and can provide a thermal driving force - the quantum analog of classical absorption chillers. The dependence of the maximum attainable cooling rate on temperature, at ultra-low temperatures, is determined and shown to respect the recently-established fundamental bound based on the second and third laws of thermodynamics.
Quantum thermodynamic cooling cycle
Palao, J P; Gordon, J M; Palao, Jose P.; Kosloff, Ronnie; Gordon, Jeffrey M.
2001-01-01T23:59:59.000Z
The quantum-mechanical and thermodynamic properties of a 3-level molecular cooling cycle are derived. An inadequacy of earlier models is rectified in accounting for the spontaneous emission and absorption associated with the coupling to the coherent driving field via an environmental reservoir. This additional coupling need not be dissipative, and can provide a thermal driving force - the quantum analog of classical absorption chillers. The dependence of the maximum attainable cooling rate on temperature, at ultra-low temperatures, is determined and shown to respect the recently-established fundamental bound based on the second and third laws of thermodynamics.
Qualitative insights on fundamental mechanics
G. N. Mardari
2006-11-10T23:59:59.000Z
The gap between classical mechanics and quantum mechanics has an important interpretive implication: the Universe must have an irreducible fundamental level, which determines the properties of matter at higher levels of organization. We show that the main parameters of any fundamental model must be theory-independent. They cannot be predicted, because they cannot have internal causes. However, it is possible to describe them in the language of classical mechanics. We invoke philosophical reasons in favor of a specific model, which treats particles as sources of real waves. Experimental considerations for gravitational, electromagnetic, and quantum phenomena are outlined.
PNNL Expert Doug McMakin Discusses Millimeter Wave Technology
Doug McMakin
2012-12-31T23:59:59.000Z
Electrical Engineer Doug McMakin discusses Millimeter Wave Holographic technology, which uses non-harmful, ultrahigh-frequency radio waves to penetrate clothing to detect and identify concealed objects, as well as obtain accurate body measurements.
McMASTER SECURITY SERVICES ANNUAL REPORT 2007
Thompson, Michael
McMASTER SECURITY SERVICES ANNUAL REPORT 2007 #12;#12;Table of Contents MCMASTER SECURITY SERVICES .................................................................................................................................6 MCMASTER SECURITY SERVICES WHO WE .......................................................................................................................29 #12;#12;5 MCMASTER SECURITY SERVICES MISSION STATEMENT Developing a safe and secure environment
EA-1262: McKay Bypass Canal Extension, Golden, Colorado
Broader source: Energy.gov [DOE]
This EA evaluates the environmental impacts for the proposal to extend the McKay Bypass Canal in order to route water from the existing Canal north of the Walnut Creek drainage on the east side of...
Transportation Center Seminar........ Elaine Croft McKenzie
Bustamante, Fabián E.
Transportation Center Seminar........ Elaine Croft McKenzie PhD Candidate, Civil & Environmental Engineering; Transportation Center Dissertation Year Fellow Northwestern University "A Framework be valued in light of their total environmental and economic footprint over the planning horizon. Currently
Rossiter-McLaughlin Observations of 55 Cnc e
Lopez-Morales, Mercedes; Rodler, Florian; Dumusque, Xavier; Buchhave, Lars A; Harutyunyan, A; Hoyer, Sergio; Alonso, Roi; Gillon, Michael; Kaib, Nathan A; Latham, David W; Lovis, Christophe; Pepe, Francesco; Queloz, Didier; Raymond, Sean N; Segransan, Damien; Waldmann, Ingo P; Udry, Stephane
2014-01-01T23:59:59.000Z
We present Rossiter-McLaughlin observations of the transiting super-Earth 55 Cnc e collected during six transit events between January 2012 and November 2013 with HARPS and HARPS-N. We detect no radial-velocity signal above 35 cm/s (3-sigma) and confine the stellar v sin i to 0.2 +/- 0.5 km/s. The star appears to be a very slow rotator, producing a very low amplitude Rossiter-McLaughlin effect. Given such a low amplitude, the Rossiter-McLaughlin effect of 55 Cnc e is undetected in our data, and any spin-orbit angle of the system remains possible. We also performed Doppler tomography and reach a similar conclusion. Our results offer a glimpse of the capacity of future instrumentation to study low amplitude Rossiter-McLaughlin effects produced by super-Earths.
The John McKay Center Policies and Procedures
Zhou, Chongwu
;3 "Welcome to the John McKay Center, a cutting-edge facility designed for the Trojan student-athlete, coaches trainers and physicians to provide world-class care. 4.) Provide a "Wow Factor" In Recruiting. Through
MELANIE HUGHES McDERMOTT mmcdermott@aesop.rutgers.edu
MELANIE HUGHES McDERMOTT mmcdermott@aesop.rutgers.edu Department of Human Ecology Cook Office Fellowship and Baker-Bidwell Research Fellowship, University of California, Berkeley (1993-94). · Kappa Kappa
MC++: Parallel, portable, Monte Carlo neutron transport in C++
Lee, S.R.; Cummings, J.C. [Los Alamos National Lab., NM (United States); Nolen, S.D. [Texas A& M Univ., College Station, TX (United States). Dept. of Nuclear Engineering
1997-02-01T23:59:59.000Z
We have developed an implicit Monte Carlo neutron transport code in C++ using the Parallel Object-Oriented Methods and Applications (POOMA) class library. MC++ runs in parallel on and is portable to a wide variety of platforms, including MPPs, clustered SMPs, and individual workstations. It contains appropriate classes and abstractions for particle transport and parallelism. Current capabilities of MC++ are discussed, along with future plans and physics and performance results on many different platforms.
McKenzie River Subbasin Assessment, Summary Report 2000.
Alsea Geospatial, Inc.
2000-02-01T23:59:59.000Z
This document summarizes the findings of the McKenzie River Subbasin Assessment: Technical Report. The subbasin assessment tells a story about the McKenzie River watershed. What is the McKenzie's ecological history, how is the McKenzie doing today, and where is the McKenzie watershed headed ecologically? Knowledge is a good foundation for action. The more we know, the better prepared we are to make decisions about the future. These decisions involve both protecting good remaining habitat and repairing some of the parts that are broken in the McKenzie River watershed. The subbasin assessment is the foundation for conservation strategy and actions. It provides a detailed ecological assessment of the lower McKenzie River and floodplain, identifies conservation and restoration opportunities, and discusses the influence of some upstream actions and processes on the study area. The assessment identifies restoration opportunities at the reach level. In this study, a reach is a river segment from 0.7 to 2.7 miles long and is defined by changes in land forms, land use, stream junctions, and/or cultural features. The assessment also provides flexible tools for setting priorities and planning projects. The goal of this summary is to clearly and concisely extract the key issues, findings, and recommendations from the full-length Technical Report. The high priority recommended action items highlight areas that the McKenzie Watershed Council can significantly influence, and that will likely yield the greatest ecological benefit. People are encouraged to read the full Technical Report if they are interested in the detailed methods, findings, and references used in this study.
A Tribute to Richard D. McKnight
J. Blair Briggs; Robert W. Schaefer
2014-06-01T23:59:59.000Z
Richard D. McKnight passed away on 28 August 2013. Dick was known to most for his technical excellence; leadership; and kind, thoughtful demeanor. The authors have attempted to capture, in a few short pages, elements of each of those qualities that defined Dick McKnight. The authors will then conclude with some personal memories of a man they looked to as a dear colleague, mentor, and friend.
Ghrelin inhibits the apoptosis of MC3T3-E1 cells through ERK and AKT signaling pathway
Liang, Qiu-Hua; Liu, Yuan; Wu, Shan-Shan; Cui, Rong-Rong; Yuan, Ling-Qing, E-mail: allenylq@hotmail.com; Liao, Er-Yuan, E-mail: eyliao@21cn.com
2013-11-01T23:59:59.000Z
Ghrelin is a 28-amino-acid peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR) and strongly stimulates the release of growth hormone from the hypothalamus–pituitary axis. Previous studies have identified the important physiological effects of ghrelin on bone metabolism, such as regulating proliferation and differentiation of osteoblasts, independent of GH/IGF-1 axis. However, research on effects and mechanisms of ghrelin on osteoblast apoptosis is still rare. In this study, we identified expression of GHSR in MC3T3-E1 cells and determined the effects of ghrelin on the apoptosis of osteoblastic MC3T3-E1 cells and the mechanism involved. Our data demonstrated that ghrelin inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as determined by terminal deoxynucleotidyl transferase-mediated deoxyribonucleotide triphosphate nick end-labeling (TUNEL) and ELISA assays. Moreover, ghrelin upregulated Bcl-2 expression and downregulated Bax expression in a dose-dependent manner. Our study also showed decreased activated caspase-3 activity under the treatment of ghrelin. Further study suggested that ghrelin stimulated the phosphorylation of ERK and AKT. Pretreatment of cells with the ERK inhibitor PD98059, PI3K inhibitor LY294002, and GHSR-siRNA blocked the ghrelin-induced activation of ERK and AKT, respectively; however, ghrelin did not stimulate the phosphorylation of p38 or JNK. PD90859, LY294002 and GHSR-siRNA attenuated the anti-apoptosis effect of ghrelin in MC3T3-E1 cells. In conclusion, ghrelin inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, which may be mediated by activating the GHSR/ERK and GHSR/PI3K/AKT signaling pathways. - Highlights: • We explored the effects of ghrelin on serum deprivation-induced MC3T3-E1 cells apoptosis. • Both ELISA and TUNEL were used to detect the apoptosis. • The receptor of ghrelin, GHSR, was expressed in MC3T3-E1 cells. • Both Akt and ERK are critical adaptor molecules to mediate the effects of ghrelin.
Presented by the Sustainability Projects Fund and the McGill Office of Sustainability
Ruthazer, Edward
Presented by the Sustainability Projects Fund and the McGill Office of Sustainability Please of sustainability at McGill, from a life-cycle perspective Primarily impact the McGill campus community Be led with the mission of the Sustainability Projects Fund: to build a culture of sustainability among the McGill campus
1McNEILL: JITTER IN PHASE-LOCKED LOOPS Jitter in Phase-Locked Loops
McNeill, John A.
1McNEILL: JITTER IN PHASE-LOCKED LOOPS Jitter in Phase-Locked Loops John McNeill Worcester Polytechnic Institute #12;2McNEILL: JITTER IN PHASE-LOCKED LOOPS Course Overview Â· Basic Theory Â· Applications Â· Measurement Techniques Â· Test Issues Â· Design Measurement Techniques Design Tools #12;3McNEILL: JITTER
McGill University Library Association of Research Libraries / Texas A&M University
Barthelat, Francois
.libqual.org 2012 Survey 9,612 #12;#12;McGill University Library Colleen Cook David Green McGill University Cook David Green McGill University Association of Research Libraries Fred Heath Martha KyrillidouMcGill University Library Association of Research Libraries / Texas A&M University www
Big doctor on campus Dr. McGarvey wins District Teacher of the
Stanford, Kyle
Big doctor on campus Dr. McGarvey wins District Teacher of the Year award. Nathan Gonzales Staff. John McGarvey. Unique is one way to put it, award-winning is another one entirely. For 20 years, Dr. Mc on the floor. It took me almost three months to win them over." Through the years, however, McGarvey began
Optics, Mechanics and Quantization of Reparametrization Systems
M. Navarro; J. Guerrero; V. Aldaya
1994-04-20T23:59:59.000Z
In this paper we regard the dynamics obtained from Fermat principle as begin the classical theory of light. We (first-)quantize the action and show how close we can get to the Maxwell theory. We show that Quantum Geometric Optics is not a theory of fields in curved space. Considering Classical Mechanics to be on the same footing, we show the parallelism between Quantum Mechanics and Quantum Geometric Optics. We show that, due to the reparametrization invariance of the classical theories, the dynamics of the quantum theories is given by a Hamiltonian constraint. Some implications of the above analogy in the quantization of true reparameterization invariant systems are discussed.
J. Twamley; G. J. Milburn
2007-02-12T23:59:59.000Z
We uncover a new type of unitary operation for quantum mechanics on the half-line which yields a transformation to ``Hyperbolic phase space''. We show that this new unitary change of basis from the position x on the half line to the Hyperbolic momentum $p_\\eta$, transforms the wavefunction via a Mellin transform on to the critial line $s=1/2-ip_\\eta$. We utilise this new transform to find quantum wavefunctions whose Hyperbolic momentum representation approximate a class of higher transcendental functions, and in particular, approximate the Riemann Zeta function. We finally give possible physical realisations to perform an indirect measurement of the Hyperbolic momentum of a quantum system on the half-line.
D. Gross; J. Eisert
2010-05-01T23:59:59.000Z
We introduce the notion of quantum computational webs: These are quantum states universal for measurement-based computation which can be built up from a collection of simple primitives. The primitive elements - reminiscent of building blocks in a construction kit - are (i) states on a one-dimensional chain of systems ("computational quantum wires") with the power to process one logical qubit and (ii) suitable couplings which connect the wires to a computationally universal "web". All elements are preparable by nearest-neighbor interactions in a single pass - a type of operation well-suited for a number of physical architectures. We provide a complete classification of qubit wires. This is first instance where a physically well-motivated class of universal resources can be fully understood. Finally, we sketch possible realizations in superlattices, and explore the power of coupling mechanisms based on Ising or exchange-interactions.
Quantum Interest in (3+1) dimensional Minkowski space
Gabriel Abreu; Matt Visser
2009-03-05T23:59:59.000Z
The so-called "Quantum Inequalities", and the "Quantum Interest Conjecture", use quantum field theory to impose significant restrictions on the temporal distribution of the energy density measured by a time-like observer, potentially preventing the existence of exotic phenomena such as "Alcubierre warp-drives" or "traversable wormholes". Both the quantum inequalities and the quantum interest conjecture can be reduced to statements concerning the existence or non-existence of bound states for a certain one-dimensional quantum mechanical pseudo-Hamiltonian. Using this approach, we shall provide a simple proof of one version of the Quantum Interest Conjecture in (3+1) dimensional Minkowski space.
Quantum information science and complex quantum systems
Michael A. Nielsen
2002-10-01T23:59:59.000Z
What makes quantum information science a science? This paper explores the idea that quantum information science may offer a powerful approach to the study of complex quantum systems.
Fast Quantum Methods for Optimization
Sergio Boixo; Gerardo Ortiz; Rolando Somma
2014-09-08T23:59:59.000Z
Discrete combinatorial optimization consists in finding the optimal configuration that minimizes a given discrete objective function. An interpretation of such a function as the energy of a classical system allows us to reduce the optimization problem into the preparation of a low-temperature thermal state of the system. Motivated by the quantum annealing method, we present three strategies to prepare the low-temperature state that exploit quantum mechanics in remarkable ways. We focus on implementations without uncontrolled errors induced by the environment. This allows us to rigorously prove a quantum advantage. The first strategy uses a classical-to-quantum mapping, where the equilibrium properties of a classical system in $d$ spatial dimensions can be determined from the ground state properties of a quantum system also in $d$ spatial dimensions. We show how such a ground state can be prepared by means of quantum annealing, including quantum adiabatic evolutions. This mapping also allows us to unveil some fundamental relations between simulated and quantum annealing. The second strategy builds upon the first one and introduces a technique called spectral gap amplification to reduce the time required to prepare the same quantum state adiabatically. If implemented on a quantum device that exploits quantum coherence, this strategy leads to a quadratic improvement in complexity over the well-known bound of the classical simulated annealing method. The third strategy is not purely adiabatic; instead, it exploits diabatic processes between the low-energy states of the corresponding quantum system. For some problems it results in an exponential speedup (in the oracle model) over the best classical algorithms.
Quantum metrology and its application in biology
Michael A. Taylor; Warwick P. Bowen
2014-09-03T23:59:59.000Z
Quantum metrology provides a route to overcome practical limits in sensing devices. It holds particular relevance in biology, where sensitivity and resolution constraints restrict applications both in fundamental biophysics and in medicine. Here, we review quantum metrology from this biological context. The understanding of quantum mechanics developed over the past century has already enabled important applications in biology, including positron emission tomography (PET) with entangled photons, magnetic resonance imaging (MRI) using nuclear magnetic resonance, and bio-magnetic imaging with superconducting quantum interference devices (SQUIDs). With the birth of quantum information science came the realization that an even greater range of applications arise from the ability to not just understand, but to engineer coherence and correlations in systems at the quantum level. In quantum metrology, quantum coherence and quantum correlations are engineered to enable new approaches to sensing. This review focusses specifically on optical quantum metrology, where states of light that exhibit non-classical photon correlations are used to overcome practical and fundamental constraints, such as the shot-noise and diffraction limits. Recent experiments have demonstrated quantum enhanced sensing of biological systems, and established the potential for quantum metrology in biophysical research. These experiments have achieved capabilities that may be of significant practical benefit, including enhanced sensitivity and resolution, immunity to imaging artifacts, and characterisation of the biological response to light at the single-photon level. New quantum measurement techniques offer even greater promise, raising the prospect for improved multi-photon microscopy and magnetic imaging, among many other possible applications.
Quantum entanglement in the multiverse
Salvador Robles-Perez; Pedro F. Gonzalez-Diaz
2012-07-26T23:59:59.000Z
In this paper it is shown that the quantum state of a multiverse made up of classically disconnected regions of the space-time, whose dynamical evolution is dominated by a homogeneous and isotropic fluid, is given by a squeezed state. These are typical quantum states that have no classical counterpart and, therefore, they allow us to analyze the violation of classical inequalities as well as the EPR argument in the context of the quantum multiverse. The thermodynamical properties of entanglement are calculated for a composite quantum state of two universes whose states are quantum mechanically correlated. The energy of entanglement between the positive and negative modes of a scalar field, which correspond to the expanding and contracting branches of a phantom universe, respectively, are also computed.
Quantum dynamics of elementary reactions in the gas phase and...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
reactions studied by these very detailed quantum mechanical methods are often at the heart of important processes in combustion and catalysis. Despite the importance of the...
Reversible computation as a model for the quantum measurement process
Karl Svozil
2009-04-15T23:59:59.000Z
One-to-one reversible automata are introduced. Their applicability to a modelling of the quantum mechanical measurement process is discussed.
A quantitative account of quantum effects in liquid water. |...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
report quantum statistical mechanical simulations of liquid water with the TTM2.1-F flexible, polarizable interaction potential for water. The potential is the first...
Natural Inflation and Quantum Gravity
Anton de la Fuente; Prashant Saraswat; Raman Sundrum
2015-01-29T23:59:59.000Z
Cosmic Inflation provides an attractive framework for understanding the early universe and the cosmic microwave background. It can readily involve energies close to the scale at which Quantum Gravity effects become important. General considerations of black hole quantum mechanics suggest nontrivial constraints on any effective field theory model of inflation that emerges as a low-energy limit of quantum gravity, in particular the constraint of the Weak Gravity Conjecture. We show that higher-dimensional gauge and gravitational dynamics can elegantly satisfy these constraints and lead to a viable, theoretically-controlled and predictive class of Natural Inflation models.
Doering, Tamara
The McDonnell International Scholars Academy Overview The McDonnell Academy provides graduate at Washington University in St. Louis. A core mission of the McDonnell International Scholars Academy is to develop future global leaders. The Academy pursues this by recruiting outstanding graduates of partner
Applications of Feedback Control in Quantum Systems
Kurt Jacobs
2006-05-02T23:59:59.000Z
We give an introduction to feedback control in quantum systems, as well as an overview of the variety of applications which have been explored to date. This introductory review is aimed primarily at control theorists unfamiliar with quantum mechanics, but should also be useful to quantum physicists interested in applications of feedback control. We explain how feedback in quantum systems differs from that in traditional classical systems, and how in certain cases the results from modern optimal control theory can be applied directly to quantum systems. In addition to noise reduction and stabilization, an important application of feedback in quantum systems is adaptive measurement, and we discuss the various applications of adaptive measurements. We finish by describing specific examples of the application of feedback control to cooling and state-preparation in nano-electro-mechanical systems and single trapped atoms.
R. Tsekov
2012-12-05T23:59:59.000Z
The Brownian motion of a light quantum particle in a heavy classical gas is theoretically described and a new expression for the friction coefficient is obtained for arbitrary temperature. At zero temperature it equals to the de Broglie momentum of the mean free path divided by the mean free path. Alternatively, the corresponding mobility of the quantum particle in the classical gas is equal to the square of the mean free path divided by the Planck constant. The Brownian motion of a quantum particle in a quantum environment is also discussed.
Transport and Dissipation in Quantum Pumps
J. E. Avron; A. Elgart; G. M. Graf; L. Sadun
2003-05-23T23:59:59.000Z
This paper is about adiabatic transport in quantum pumps. The notion of ``energy shift'', a self-adjoint operator dual to the Wigner time delay, plays a role in our approach: It determines the current, the dissipation, the noise and the entropy currents in quantum pumps. We discuss the geometric and topological content of adiabatic transport and show that the mechanism of Thouless and Niu for quantized transport via Chern numbers cannot be realized in quantum pumps where Chern numbers necessarily vanish.
Energy Inequalities in Quantum Field Theory
Christopher J. Fewster
2005-01-31T23:59:59.000Z
Quantum fields are known to violate all the pointwise energy conditions of classical general relativity. We review the subject of quantum energy inequalities: lower bounds satisfied by weighted averages of the stress-energy tensor, which may be regarded as the vestiges of the classical energy conditions after quantisation. Contact is also made with thermodynamics and related issues in quantum mechanics, where such inequalities find analogues in sharp Gaarding inequalities.
Optimum phase space probabilities from quantum tomography
Roy, Arunabha S., E-mail: roy.arunabha@gmail.com [King's College, London (United Kingdom); Roy, S. M., E-mail: smroy@hbcse.tifr.res.in [HBCSE, Tata Institute of Fundamental Research, Mumbai (India)
2014-01-15T23:59:59.000Z
We determine a positive normalised phase space probability distribution P with minimum mean square fractional deviation from the Wigner distribution W. The minimum deviation, an invariant under phase space rotations, is a quantitative measure of the quantumness of the state. The positive distribution closest to W will be useful in quantum mechanics and in time frequency analysis. The position-momentum correlations given by the distribution can be tested experimentally in quantum optics.
Anomalous critical fields in quantum critical superconductors
Putzke, C.; Walmsley, P.; Fletcher, J.D.; Malone, L.; Vignolles, D.; Proust, C.; Badoux, S.; See, P.; Beere, H.E.; Ritchie, D.A.; Kasahara, S.; Mizukami, Y.; Shibauchi, T.; Matsuda, Y.; Carrington, A.
2015-01-01T23:59:59.000Z
-temperature superconductivity. However, the exact mechanism by which this occurs remains poorly understood. The iron-pnictide superconductor BaFe2(As1?xPx)2 is perhaps the clearest example to date of a high temperature quantum critical superconductor, and so it is a... mixing of antiferromagnetism and superconductivity, suggesting that a highly unusual vortex state is realised in quantum critical superconductors. Quantum critical points (QCPs) can be associated with a variety of different order-disorder phenomena...
Weedbrook, Christian
The science of quantum information has arisen over the last two decades centered on the manipulation of individual quanta of information, known as quantum bits or qubits. Quantum computers, quantum cryptography, and quantum ...
Black holes are almost optimal quantum cloners
C. Adami; G. Ver Steeg
2015-04-15T23:59:59.000Z
If black holes were able to clone quantum states, a number of paradoxes in black hole physics would disappear. However, the linearity of quantum mechanics forbids exact cloning of quantum states. Here we show that black holes indeed clone incoming quantum states with a fidelity that depends on the black hole's absorption coefficient, without violating the no-cloning theorem because the clones are only approximate. Perfectly reflecting black holes are optimal universal "quantum cloning machines" and operate on the principle of stimulated emission, exactly as their quantum optical counterparts. In the limit of perfect absorption, the fidelity of clones is equal to what can be obtained via quantum state estimation methods. But for any absorption probability less than one, the cloning fidelity is nearly optimal as long as $\\omega/T\\geq10$, a common parameter for modest-sized black holes.
Spinless Quantum Field Theory and Interpretation
Dong-Sheng Wang
2013-03-07T23:59:59.000Z
Quantum field theory is mostly known as the most advanced and well-developed theory in physics, which combines quantum mechanics and special relativity consistently. In this work, we study the spinless quantum field theory, namely the Klein-Gordon equation, and we find that there exists a Dirac form of this equation which predicts the existence of spinless fermion. For its understanding, we start from the interpretation of quantum field based on the concept of quantum scope, we also extract new meanings of wave-particle duality and quantum statistics. The existence of spinless fermion is consistent with spin-statistics theorem and also supersymmetry, and it leads to several new kinds of interactions among elementary particles. Our work contributes to the study of spinless quantum field theory and could have implications for the case of higher spin.
Quantum optical technologies for metrology, sensing and imaging
Jonathan P. Dowling; Kaushik P. Seshadreesan
2015-02-27T23:59:59.000Z
Over the past 20 years, bright sources of entangled photons have led to a renaissance in quantum optical interferometry. Optical interferometry has been used to test the foundations of quantum mechanics and implement some of the novel ideas associated with quantum entanglement such as quantum teleportation, quantum cryptography, quantum lithography, quantum computing logic gates, and quantum metrology. In this paper, we focus on the new ways that have been developed to exploit quantum optical entanglement in quantum metrology to beat the shot-noise limit, which can be used, e.g., in fiber optical gyroscopes and in sensors for biological or chemical targets. We also discuss how this entanglement can be used to beat the Rayleigh diffraction limit in imaging systems such as in LIDAR and optical lithography.
mc4qcd: Online Analysis Tool for Lattice QCD
Massimo Di Pierro; Yaoqian Zhong; Brian Schinazi
2010-05-19T23:59:59.000Z
mc4qcd is a web based collaboration tool for analysis of Lattice QCD data. Lattice QCD computations consists of a large scale Markov Chain Monte Carlo. Multiple measurements are performed at each MC step. Our system acquires the data by uploading log files, parses them for results of measurements, filters the data, mines for required information by aggregating results, represents the results as plots and histograms, and it further allows refining and interaction by fitting the results. The system computes moving averages and autocorrelations, builds bootstrap samples and bootstrap errors, and allows modeling the data using Bayesian correlated constrained linear and non-linear fits. It can be scripted to allow real time visualization of results form an ongoing computation. The system is modular and it can be adapted to automating the analysis workflow of different types of MC computations.
McKenzie River Subbasin Assessment, Technical Report 2000.
Alsea Geospatial, Inc.
2000-02-01T23:59:59.000Z
This document details the findings of the McKenzie River Subbasin Assessment team. The goal of the subbasin assessment is to provide an ecological assessment of the McKenzie River Floodplain, identification of conservation and restoration opportunities, and discussion of the influence of some upstream actions and processes. This Technical Report can be viewed in conjunction with the McKenzie River Subbasin Summary or as a stand-alone document. The purpose of the technical report is to detail the methodology and findings of the consulting team that the observations and recommendations in the summary document are based on. This part, Part I, provides an introduction to the subbasin and a general overview. Part II details the specific findings of the science team. Part III provides an explanation and examples of how to use the data that has been developed through this assessment to aid in prioritizing restoration activities. Part III also includes the literature cited and appendices.
Topological Black Holes in Quantum Gravity
J. Kowalski-Glikman; D. Nowak-Szczepaniak
2000-07-31T23:59:59.000Z
We derive the black hole solutions with horizons of non-trivial topology and investigate their properties in the framework of an approach to quantum gravity being an extension of Bohm's formulation of quantum mechanics. The solutions we found tend asymptotically (for large $r$) to topological black holes. We also analyze the thermodynamics of these space-times.
The Quantum-Classical and Mind-Brain Linkages: The Quantum Zeno Effect in Binocular Rivalry
Henry P. Stapp
2007-11-05T23:59:59.000Z
A quantum mechanical theory of the relationship between perceptions and brain dynamics based on von Neumann's theory of measurments is applied to a recent quantum theoretical treatment of binocular rivaly that makes essential use of the quantum Zeno effect to give good fits to the complex available empirical data. The often-made claim that decoherence effects in the warm, wet, noisy brain must eliminate quantum effects at the macroscopic scale pertaining to perceptions is examined, and it is argued, on the basis of fundamental principles. that the usual decoherence effects will not upset the quantum Zeno effect that is being exploited in the cited work.
Quantum Logic Gates using q-deformed Oscillators
Debashis Gangopadhyay; Mahendra Nath Sinha Roy
2006-07-14T23:59:59.000Z
We show that the quantum logic gates, {\\it viz.} the single qubit Hadamard and Phase Shift gates, can also be realised using q-deformed angular momentum states constructed via the Jordan-Schwinger mechanism with two q-deformed oscillators. {\\it Keywords :} quantum logic gates ; q-deformed oscillators ; quantum computation {\\it PACS:} 03.67.Lx ; 02.20.Uw
Characteristics and development report for the MC3573 thermal battery
Street, H.K.
1983-02-01T23:59:59.000Z
This report describes the design intent, product characteristics, and development history of the MC3573 high-current, electrically activated thermal battery. This battery is required to operate five to six times longer than the usual weapon system power battery. The MC3573 employs the Li(Si)/LiCl.KCl/FeS/sub 2/ electrochemical system. The battery is a right-circular cylinder with attached mounting brackets. It measures 122.1 mm in length, 88.9 mm in diameter, and stands 96.2 mm high. The battery is the power supply for the W81 and W85 JTA telemetry systems.
McFadden Ridge Wind Farm | Open Energy Information
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McCook, Illinois: Energy Resources | Open Energy Information
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McGee Mountain Geothermal Area | Open Energy Information
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McKeown Development Company Ltd | Open Energy Information
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Lloyd, S.
1992-01-01T23:59:59.000Z
Digital computers are machines that can be programmed to perform logical and arithmetical operations. Contemporary digital computers are universal,'' in the sense that a program that runs on one computer can, if properly compiled, run on any other computer that has access to enough memory space and time. Any one universal computer can simulate the operation of any other; and the set of tasks that any such machine can perform is common to all universal machines. Since Bennett's discovery that computation can be carried out in a non-dissipative fashion, a number of Hamiltonian quantum-mechanical systems have been proposed whose time-evolutions over discrete intervals are equivalent to those of specific universal computers. The first quantum-mechanical treatment of computers was given by Benioff, who exhibited a Hamiltonian system with a basis whose members corresponded to the logical states of a Turing machine. In order to make the Hamiltonian local, in the sense that its structure depended only on the part of the computation being performed at that time, Benioff found it necessary to make the Hamiltonian time-dependent. Feynman discovered a way to make the computational Hamiltonian both local and time-independent by incorporating the direction of computation in the initial condition. In Feynman's quantum computer, the program is a carefully prepared wave packet that propagates through different computational states. Deutsch presented a quantum computer that exploits the possibility of existing in a superposition of computational states to perform tasks that a classical computer cannot, such as generating purely random numbers, and carrying out superpositions of computations as a method of parallel processing. In this paper, we show that such computers, by virtue of their common function, possess a common form for their quantum dynamics.
Lloyd, S.
1992-12-01T23:59:59.000Z
Digital computers are machines that can be programmed to perform logical and arithmetical operations. Contemporary digital computers are ``universal,`` in the sense that a program that runs on one computer can, if properly compiled, run on any other computer that has access to enough memory space and time. Any one universal computer can simulate the operation of any other; and the set of tasks that any such machine can perform is common to all universal machines. Since Bennett`s discovery that computation can be carried out in a non-dissipative fashion, a number of Hamiltonian quantum-mechanical systems have been proposed whose time-evolutions over discrete intervals are equivalent to those of specific universal computers. The first quantum-mechanical treatment of computers was given by Benioff, who exhibited a Hamiltonian system with a basis whose members corresponded to the logical states of a Turing machine. In order to make the Hamiltonian local, in the sense that its structure depended only on the part of the computation being performed at that time, Benioff found it necessary to make the Hamiltonian time-dependent. Feynman discovered a way to make the computational Hamiltonian both local and time-independent by incorporating the direction of computation in the initial condition. In Feynman`s quantum computer, the program is a carefully prepared wave packet that propagates through different computational states. Deutsch presented a quantum computer that exploits the possibility of existing in a superposition of computational states to perform tasks that a classical computer cannot, such as generating purely random numbers, and carrying out superpositions of computations as a method of parallel processing. In this paper, we show that such computers, by virtue of their common function, possess a common form for their quantum dynamics.
Changing Obsidian Sources at the Lost Dune and McCoy Creek Sites, Blitzen Valley, Southeast Oregon
Lyons, William H; Thomas, Scott P; Skinner, Craig E
2001-01-01T23:59:59.000Z
Dune (35HA792); MC = McCoy Creek (35HA1263) Component ffl;sample. Provenience of McCoy Creek artifacts from Musil (AT THE LOST DUNE AND MCCOY CREEK SITES OREGON NEVADA Burns
Newsline Summer 2003 McGill Anesthesia Newsletter
Barthelat, Francois
Newsline Summer 2003 McGill Anesthesia Newsletter TTTTThe first Kresimir Krnjevic Research Award for AAAAAt the 18th Annual Harold Griffith Memorial 1st Kresimir Krnjevic Anesthesia Research Award outstanding resident project, was Dr. Irina Strigo. Drs Kris Krnjevic and Gary Bennett of the Anesthesia
Newsline Winter 2003 McGill Anesthesia Newsletter
Barthelat, Francois
1 Newsline Winter 2003 McGill Anesthesia Newsletter This year at our Annual Wesley Bourne Memorial Award for Excellence in the Teaching of Anesthesia. Teaching the art and science of anesthesia anesthesia. Dr. Deschamps was this year's residents' choice because of his knowledge, his enthusiasm
President's Report to McMaster University's Board of Governors
Haykin, Simon
--but always focused clearly on the student and the realization of the student's potential. Here in Ontario,000 gift to provide greater accessibility to library, enhance learning for business students McMaster has services of the University libraries and to create a dynamic learning space for business students at its
Finding Glass Kenton McHenry, Jean Ponce
Forsyth, David
Finding Glass Kenton McHenry, Jean Ponce Beckman Institute University of Illinois Urbana, IL 61801. This paper addresses the problem of finding glass ob- jects in images. Visual cues obtained by combining with the strong highlights typical of glass surfaces are used to train a hierarchy of classifiers, identify glass
Tracking Interacting People Stephen J. McKenna
Duric, Zoran
people move in groups or interact with other peo- ple cause considerable difficulty to many trackingTracking Interacting People Stephen J. McKenna Department of Applied Computing University of Dundee, wechsler @cs.gmu.edu Abstract A computer vision system for tracking multiple people in relatively
Tracking Groups of People Stephen J. McKenna
Duric, Zoran
in groups or interact with other people cause considerable difficulty for many tracking schemes. HoweverTracking Groups of People Stephen J. McKenna Department of Applied Computing, University of Dundee, University of Maryland, College Park, MD 20742-3275 A computer vision system for tracking multiple people
Systematic Nonlinear Planning David McAllester \\Lambda
McAllester, David
of Naval Research contract N00014Â85ÂKÂ0124 and N00014Â89ÂjÂ3202 earliest planning systems were ``liftedSystematic Nonlinear Planning David McAllester \\Lambda MIT Artificial Intelligence Laboratory dam verifiable, lifting transformation. PreviÂ ous planners have been designed directly as lifted proÂ cedures