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A gauge-invariant Wigner quasi-distribution function for charged particles in classical electromagnetic fields is derived in a rigorous way. Its relation to the axial gauge is discussed, as well as the relation between the kinetic and…

Condensed Matter · Physics 2009-11-07 M. Levanda , V Fleurov

We study decoherence, diffusion, friction, and how they thermalize a planar rotor in the presence of an external potential. Representing the quantum master equation in terms of auxiliary Wigner functions in periodic phase space not only…

Quantum Physics · Physics 2025-04-30 Birthe Schrinski , Yoon Jun Chan , Björn Schrinski

Interactions between charged particles and light occur in real space and time, yet quantum field theory usually describes them in momentum space. Whereas this approach is well suited for calculating emission probabilities and cross…

Quantum mechanics is often developed in the position representation, but this is not necessary, and one can perform calculations in a representation-independent fashion, even for wavefunctions. In this work, we illustrate how one can…

Quantum Physics · Physics 2021-07-28 Michael Rushka , Mark Esrick , Wesley N. Mathews , J. K. Freericks

Focusing particularly on one-qubit and two-qubit systems, I explain how the quantum state of a system of n qubits can be expressed as a real function--a generalized Wigner function--on a discrete 2^n x 2^n phase space. The phase space is…

Quantum Physics · Physics 2007-05-23 William K. Wootters

We calculate the Wigner quasiprobability distribution function of quantum elliptical vortex in elliptical beam (EEV), produced by coupling squeezed coherent states of two modes. The coupling between the two modes is performed by using beam…

Quantum Physics · Physics 2010-12-02 Abir Bandyopadhyay , Ravindra Pratap Singh

We shall revisit the conventional treatment of open quantum devices based on the Wigner-Function formalism. Our analysis will show that the artificial spatial separation between device active region and external reservoirs -properly defined…

Other Condensed Matter · Physics 2007-05-23 Luigi Genovese , David Taj , Fausto Rossi

A quantum version of transition state theory based on a quantum normal form (QNF) expansion about a saddle-centre-...-centre equilibrium point is presented. A general algorithm is provided which allows one to explictly compute QNF to any…

Chaotic Dynamics · Physics 2007-12-12 Holger Waalkens , Roman Schubert , Stephen Wiggins

Thermal fluctuations in time-dependent quantum processes are treated by a constant-temperature generalization of Wigner's formulation of quantum mechanics in phase space. To this end, quantum Nos\`e-Hoover dynamics is defined by…

Quantum Physics · Physics 2009-11-13 Alessandro Sergi , Francesco Petruccione

We prove a formula expressing the gradient of the phase function of a function $f: \mathbb R^d \mapsto \mathbb C$ as a normalized first frequency moment of the Wigner distribution for fixed time. The formula holds when $f$ is the Fourier…

Functional Analysis · Mathematics 2010-07-07 Paolo Boggiatto , Alessandro Oliaro , Patrik Wahlberg

Complex numbers appear in the Hilbert space formulation of quantum mechanics, but not in the formulation in phase space. Quantum symmetries are described by complex, unitary or antiunitary operators defining ray representations in Hilbert…

Quantum Physics · Physics 2009-11-11 A. J. Bracken

Quantum statistical mechanics is formulated as an integral over classical phase space. Some details of the commutation function for averages are discussed, as is the factorization of the symmetrization function used for the grand potential…

Quantum Physics · Physics 2018-11-05 Phil Attard

Drawing inspiration from Dirac's work on functions of non commuting observables, we develop a fresh approach to phase space descriptions of operators and the Wigner distribution in quantum mechanics. The construction presented here is…

Quantum Physics · Physics 2007-05-23 S. Chaturvedi , E. Ercolessi , G. Marmo , G. Morandi , N. Mukunda , R. Simon

We study a class of phase-space distribution functions that is generated from a Gaussian convolution of the Wigner distribution function. This class of functions represents the joint count probability in simultaneous measurements of…

Quantum Physics · Physics 2013-11-05 Hai-Woong Lee

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 Physics · Physics 2007-05-23 O. Crasser , H. Mack , W. P. Schleich

We derive a quantum version of the classical-optics Wiener-Khintchine theorem within the framework of detection of phase-space displacements with a suitably designed quantum ruler. A phase-pace based quantum mutual coherence function is…

Quantum Physics · Physics 2022-09-07 Ainara Álvarez-Marcos , Alfredo Luis

Systems built out of N-body interactions, beyond 2-body interactions, are formulated on the plane, and investigated classically and quantum mechanically (in phase space). Their Wigner Functions--the density matrices in phase-space…

High Energy Physics - Theory · Physics 2009-10-02 Thomas L Curtright , Alexios P Polychronakos , Cosmas K Zachos

Phase spaces as given by the Wigner distribution function provide a natural description of infinite-dimensional quantum systems. They are an important tool in quantum optics and have been widely applied in the context of time-frequency…

Quantum Physics · Physics 2023-10-27 Bálint Koczor , Frederik vom Ende , Maurice de Gosson , Steffen J. Glaser , Robert Zeier

We develop a dynamical theory, based on a system of ordinary differential equations describing the motion of particles which reproduces the results of quantum mechanics. The system generalizes the Hamilton equations of classical mechanics…

Quantum Physics · Physics 2012-07-12 Maxim Raykin

Special stochastic representation of the wave function in Quantum Mechanics (QM), based on soliton realization of extended particles, is suggested with the aim to model quantum states via classical computer. Entangled solitons construction…

Quantum Physics · Physics 2007-05-23 T. F. Kamalov , Yu. P. Rybakov