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We present a Wigner function-based approach for the particle density evolution in fermionic and bosonic open quantum many-body systems, including the effects of dephasing. In particular, we focus on chains of non-interacting particles…

Quantum Gases · Physics 2023-05-31 Michele Coppola , Gabriel T. Landi , Dragi Karevski

The dynamics of a spin-1/2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied, as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is…

Quantum Physics · Physics 2007-06-28 D. D. Bhaktavatsala Rao , V. Ravishankar , V. Subrahmanyam

We set up a forward--backward path integral for a point particle in a bath of photons to derive a master equation for the density matrix which describes electromagnetic dissipation and decoherence. As an application, we recalculate the…

Condensed Matter · Physics 2009-10-31 Z. Haba , H. Kleinert

A simplified Heisenberg spin model is studied in order to examine the idea of decoherence in closed quantum systems. For this purpose, we present a quantifiable definition to quantum coherence $\Xi$, and discuss in some detail a general…

Quantum Physics · Physics 2008-05-18 Olavi Dannenberg

We study the decoherence effect of quantum superposition in de Sitter (dS) spacetime due to the presence of the cosmological horizon. Using the algebraic approach of quantum field theory on curved spacetime, we derive the precise expression…

High Energy Physics - Theory · Physics 2025-01-03 Ran Li

It is commonly stated that decoherence in open quantum systems is due to growing entanglement with an environment. In practice, however, surprisingly often decoherence may equally well be described by random unitary dynamics without…

Quantum Physics · Physics 2009-10-29 Julius Helm , Walter T. Strunz

These lecture notes address an audience of physicists or mathematicians who have been exposed to a first course in quantum mechanics. We start with a brief discussion of the general "system-bath" paradigm of quantum dissipative systems,…

Quantum Physics · Physics 2008-09-26 Florian Marquardt , Annett Püttmann

Open quantum systems undergo decoherence, which is responsible for the transition from quantum to classical behavior. The time scale in which decoherence takes place can be analyzed using upper limits to its rate. We examine the dynamics of…

Quantum Physics · Physics 2024-06-10 Yifeng Yang , Zhenyu Xu , Adolfo del Campo

We propose a phase-space representation concept in terms of the Wigner function for a quantum harmonic oscillator model that exhibits the semiconfinement effect through its mass varying with the position. The new method is used to compute…

Quantum Physics · Physics 2024-02-01 S. M. Nagiyev , A. M. Jafarova , E. I. Jafarov

We present an approach that allows quantifying decoherence processes in an open quantum system subject to external time-dependent control. Interactions with the environment are modeled by a standard bosonic heat bath. We develop two…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Dmitry Solenov , Vladimir Privman

The Wigner function formalism has been applied to the analysis of elastic scattering processes. The new element of known formalism is the choice of the phase space on which the Wigner function is defined. This phase space is 4-dimensional…

High Energy Physics - Phenomenology · Physics 2010-08-09 I. Perevalova , M. Polyakov , O. Soldatenko , A. Vall

We consider an ensemble of quantum systems whose average evolution is described by a density matrix, solution of a Lindblad-Kossakowski differential equation. We focus on the special case where the decoherence is only due to a highly…

Mathematical Physics · Physics 2008-01-11 Mazyar Mirrahimi , Pierre Rouchon

Dito and Turrubiates recently introduced an interesting model of the dissipative quantum mechanics of a damped harmonic oscillator in phase space. Its key ingredient is a non-Hermitian deformation of the Moyal star product with the damping…

Quantum Physics · Physics 2009-03-25 B. Belchev , M. A. Walton

We study numerically the dynamics of excitons on discrete rings in the presence of static disorder. Based on continuous-time quantum walks we compute the time evolution of the Wigner function (WF) both for pure diagonal (site) disorder, as…

Quantum Physics · Physics 2007-05-23 Oliver Muelken , Veronika Bierbaum , Alexander Blumen

I investigate the propagator of the Wigner function for a dissipative chaotic quantum map. I show that a small amount of dissipation reduces the propagator of sufficiently smooth Wigner functions to its classical counterpart, the…

chao-dyn · Physics 2009-10-31 Daniel Braun

We study the decoherence and thermalization of an Unruh-DeWitt detector linearly coupled to the free massless scalar field in flat spacetime of arbitrary dimensions ($d\geq 2$). The initial state of the detector is chosen to be a pure state…

High Energy Physics - Theory · Physics 2023-03-28 Hao Xu

The processes of radiation damping and decoherence in Quantum Electrodynamics are studied from an open system's point of view. Employing functional techniques of field theory, the degrees of freedom of the radiation field are eliminated to…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer , Francesco Petruccione

We study the coherence in time and space of electromagnetic fields propagated through complex media. Whether for localization, imaging or telecommunication, the development of dedicated numerical techniques is generally based on the…

Computational Physics · Physics 2022-04-21 Thomas Fromenteze , Matthieu Davy , Okan Yurduseven , Yann Marie-Joseph , Cyril Decroze

We analyze the response of a complex quantum-mechanical system (e. g., a quantum dot) to a time-dependent perturbation. Assuming the dot energy spectrum and the perturbation to be described by the Gaussian Orthogonal Ensemble of random…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 D. M. Basko , M. A. Skvortsov , V. E. Kravtsov

In the framework of the Lindblad theory for open quantum systems, we determine the degree of quantum decoherence of a harmonic oscillator interacting with a thermal bath. It is found that the system manifests a quantum decoherence which is…

Quantum Physics · Physics 2009-11-13 A. Isar