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Related papers: Semiclassical analysis of Wigner functions

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Phase-space features of the Wigner flow for an anharmonic quantum system driven by the harmonic oscillator potential modified by the addition of an inverse square (one-dimension Coulomb-like) contribution are analytically described in terms…

Quantum Physics · Physics 2018-12-05 Alex E. Bernardini

The trace of an arbitrary product of quantum operators with the density operator is rendered as a multiple phase space integral of the product of their Weyl symbols with the Wigner function. Interspersing the factors with various evolution…

Quantum Physics · Physics 2016-04-20 Alfredo M. Ozorio de Almeida , Olivier Brodier

The semiclassically scaled time-dependent multi-particle Schr\"odinger equation describes, inter alia, quantum dynamics of nuclei in a molecule. It poses the combined computational challenges of high oscillations and high dimensions. This…

Numerical Analysis · Mathematics 2020-12-02 Caroline Lasser , Christian Lubich

We develop semiclassical approximations for calculating photoabsorption cross sections beyond the continuum threshold in quantum many-body systems. These approximations use the fully quantum-mechanical Wigner function of the ground state…

Atomic Physics · Physics 2023-05-24 Julien Toulouse

To quantify the effect of decoherence in quantum measurements, it is desirable to measure not merely the square modulus of the spatial wavefunction, but the entire density matrix, whose phases carry information about momentum and how pure…

Quantum Physics · Physics 2009-10-30 Max Tegmark

We study the phase-space representation of dynamics of bosons in the semiclassical regime where the occupation number of the modes is large. To this end, we employ the van Vleck-Gutzwiller propagator to obtain an approximation for the…

Quantum Gases · Physics 2019-09-04 Ranchu Mathew , Eite Tiesinga

Semiclassical approximations for various representations of a quantum state are constructed on a single (Lagrangian) surface in phase space, but it is not available for chaotic systems. An analogous evolution surface underlies semiclassical…

Quantum Physics · Physics 2025-07-11 Alfredo M. Ozorio de Almeida

Semiclassical quantization is exact only for the so called \emph{solvable} potentials, such as the harmonic oscillator. In the \emph{nonsolvable} case the semiclassical phase, given by a series in $\hbar$, yields more or less approximate…

Quantum Physics · Physics 2007-05-23 A. Matzkin

The Schr\"odinger equation in phase space is used to calculate the Wigner function for the Helium atom in the approximation of a system of two oscillators. Dissipation effect is analysed and the non-classicality of the state is studied by…

Quantum Physics · Physics 2016-08-31 H. Dessano , R. G. G. Amorim , S. C. Ulhoa , A. E. Santana

We present a simple way to quantize the well-known Margulis expander map. The result is a quantum expander which acts on discrete Wigner functions in the same way the classical Margulis expander acts on probability distributions. The…

Quantum Physics · Physics 2008-05-29 D. Gross , J. Eisert

We show that classicality emerges during quantum phase transitions due to parametric interactions without coupling to environments. The Wigner functions are explicitly calculated for the Gaussian vacuum, number, and thermal states of a free…

High Energy Physics - Phenomenology · Physics 2009-10-31 Sang Pyo Kim , Chul H. Lee

We represent both the states and the evolution of a quantum computer in phase space using the discrete Wigner function. We study properties of the phase space representation of quantum algorithms: apart from analyzing important examples,…

Quantum Physics · Physics 2009-11-07 Cesar Miquel , Juan Pablo Paz , Marcos Saraceno

We show that real polarization method can be effectively used to geometrically quantize physical systems with compact phase space, like the spin. Our method enables us to construct a wave function of a qubit in both position and momentum…

Mathematical Physics · Physics 2015-12-10 Jerzy Kijowski , Piotr Waluk , Katarzyna Senger

It has recently been shown that it is possible to represent the complete quantum state of any system as a phase-space quasi-probability distribution (Wigner function) [Phys Rev Lett 117, 180401]. Such functions take the form of expectation…

Quantum Physics · Physics 2017-08-16 R. P. Rundle , P. W. Mills , Todd Tilma , J. H. Samson , M. J. Everitt

We give a definition for the Wigner function for quantum mechanics on the Bohr compactification of the real line and prove a number of simple consequences of this definition. We then discuss how this formalism can be applied to loop quantum…

Mathematical Physics · Physics 2008-11-26 Christopher J. Fewster , Hanno Sahlmann

We calculate exactly the quantum mechanical, temporal Wigner quasiprobability density for a single-mode, degenerate parametric amplifier for a system in the Gaussian state, viz., a displaced-squeezed thermal state. The Wigner function…

Quantum Physics · Physics 2021-03-16 Moorad Alexanian

Starting from the Schr\"odinger-equation of a composite system, we derive unified dynamics of a classical harmonic system coupled to an arbitrary quantized system. The classical subsystem is described by random phase-space coordinates…

Quantum Physics · Physics 2007-05-23 Lajos Diosi

We consider the quantum kinetic-theory description for interacting massive spin-half fermions using the Wigner function formalism. We derive a general kinetic theory description assuming that the spin effects appear at the classical and…

High Energy Physics - Theory · Physics 2023-09-11 Arpan Das , Wojciech Florkowski , Avdhesh Kumar , Radoslaw Ryblewski , Rajeev Singh

An adaptation of the WKB method in the deformation quantization formalism is presented with the aim to obtain an approximate technique of solving the eigenvalue problem for energy in the phase space quantum approach. A relationship between…

Quantum Physics · Physics 2016-07-18 Jaromir Tosiek , Ruben Cordero , Francisco J. Turrubiates

The general Weyl -- Wigner formalism in finite dimensional phase spaces is investigated. Then this formalism is specified to the case of symmetric ordering of operators in an odd -- dimensional Hilbert space. A respective Wigner function on…

Quantum Physics · Physics 2017-11-22 Maciej Przanowski , Jaromir Tosiek