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Non-Gaussian correlations in a pure state are inextricably linked with non-classical features, such as a non positive-definite Wigner function. In a commonly used simulation technique in ultracold atoms and quantum optics, known as the…

Quantum Physics · Physics 2015-03-05 J. F. Corney , M. K. Olsen

The time evolution of the Wigner function for Gaussian states generated by Lindblad quantum dynamics is investigated in the semiclassical limit. A new type of phase-space dynamics is obtained for the centre of a Gaussian Wigner function,…

Quantum Physics · Physics 2019-02-01 E M Graefe , B Longstaff , T Plastow , R Schubert

We introduce the parafermionic truncated Wigner approximation ($p$TWA), a semiclassical phase-space framework for simulating the nonequilibrium dynamics of lattice systems with fractional exchange statistics. The method extends truncated…

Strongly Correlated Electrons · Physics 2026-04-01 Javad Vahedi , Martin Garttner

The exact solution of the Lindblad equation with a quadratic Hamiltonian and linear coupling operators was derived within the chord representation, that is, for the Fourier transform of the Wigner function, also known as the characteristic…

Quantum Physics · Physics 2023-10-04 Aldo R. Fernandes Neto , Alfredo M. Ozorio de Almeida , Olivier Brodier

Classical surfaces in phase space correspond to quantum states in Hilbert space. Subsystems specify factor spaces of the Hilbert space. An entangled state corresponds semiclassically to a surface that cannot be decomposed into a product of…

Quantum Physics · Physics 2007-05-23 A. M. Ozorio de Almeida

The Wigner function is known to evolve classically under the exclusive action of a quadratic hamiltonian. If the system does interact with the environment through Lindblad operators that are linear functions of position and momentum, we…

Quantum Physics · Physics 2009-11-10 O. Brodier , A. M. Ozorio de Almeida

We present a general method by which linear quantum Hamiltonian dynamics with exponentially many degrees of freedom is replaced by approximate classical nonlinear dynamics with the number of degrees of freedom (phase space dimensionality)…

Quantum Physics · Physics 2018-08-01 Jonathan Wurtz , Anatoli Polkovnikov , Dries Sels

We derive an approximate Gaussian solution of the Lindblad equation in the semiclassical limit, given a general Hamiltonian and linear coupling with the environment. The theory is carried out in the chord representation and describes the…

Quantum Physics · Physics 2009-06-24 O. Brodier , A. M. Ozorio de Almeida

In this work we present the formal background used to develop the methods used in earlier works to extend the truncated Wigner representation of quantum and atom optics in order to address multi-time problems. The truncated Wigner…

Quantum Physics · Physics 2015-06-16 L I Plimak , M K Olsen

The strictly classical propagation of an initial Wigner function, referred to as TWA or LSC-IVR, is considered to provide approximate averages, despite not being a true Wigner function: it does not represent a positive operator. We here…

Quantum Physics · Physics 2024-06-28 Kelvin Titimbo , Gabriel M. Lando , Alfredo M. Ozorio de Almeida

We derive a semiclassical approximation for the evolution generated by the Lindblad equation as a generalization of complex WKB theory. Linear coupling to the environment is assumed, but the Hamiltonian can be a general function of…

Quantum Physics · Physics 2015-05-13 O. Brodier , A. M. Ozorio de Almeida

In this paper we reconsider the notion of an optimal effective Hamiltonian for the semiclassical propagation of the Wigner distribution in phase space. An explicit expression for the optimal effective Hamiltonian is obtained in the short…

Quantum Physics · Physics 2017-05-11 Dries Sels , Fons Brosens

A semiclassical approximation for an evolving density operator, driven by a "closed" hamiltonian operator and "open" markovian Lindblad operators, is obtained. The theory is based on the chord function, i.e. the Fourier transform of the…

Quantum Physics · Physics 2020-08-18 A. M. Ozorio de Almeida , P. de M. Rios , O. Brodier

We develop a truncated Hamiltonian method to investigate the dynamics of the $(1+1)d~\phi^4$ theory following quantum quenches. The results are compared to two different semi-classical approaches, the self-consistent Gaussian approximation…

Statistical Mechanics · Physics 2022-01-12 D. Szász-Schagrin , I. Lovas , G. Takács

We modify the path integral representation of exciton transport in open quantum systems such that an exact description of the quantum fluctuations around the classical evolution of the system is possible. As a consequence, the time…

Quantum Physics · Physics 2017-04-19 Anton Ivanov , Heinz-Peter Breuer

An observer at rest with the expanding universe experiences some extra noise in the quantum vacuum, and so does an accelerated observer in a vacuum at rest (in Minkowski space). The literature mainly focuses on the ideal cases of…

General Relativity and Quantum Cosmology · Physics 2025-01-07 Ziv Landau , Ulf Leonhardt

We consider the class of non-Hermitian operators represented by infinite tridiagonal matrices, selfadjoint in an indefinite inner product space with one negative square. We approximate them with their finite truncations. Both infinite and…

Mathematical Physics · Physics 2016-08-08 Maxim Derevyagin , Luca Perotti , Michal Wojtylak

We study the dynamics of light interacting with a near-resonant atomic medium using the truncated Wigner and positive P phase-space representations. The atomic degrees of freedom are described using the Jordan-Schwinger mapping. The…

Quantum Physics · Physics 2026-02-20 Mojdeh S. Najafabadi , Joel F. Corney , Luis Sanchez Soto , Gerd Leuchs

We apply the semi-classical limit of the generalized $SO(3)$ map for representation of variable-spin systems in a four-dimensional symplectic manifold and approximate their evolution terms of effective classical dynamics on $T^{\ast…

We derive an analytical expression of a Wigner function that approximately describes the time evolution of the one-dimensional motion of a particle in a nonharmonic potential. Our method involves two exact frame transformations, accounting…

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