aqora

Density matrix description of non-equilibrium quantum transport

Prasenjit Dutt, Jens Koch, Chung‐Hou Chung +2 more

Bulletin of the American Physical SocietyMar 17, 20100 citations

On quantum mechanical transport coefficients in nonequilibrium nuclear processes with application to heavy-ion collisions

Yamen Hamdouni

The elements of the quantum mechanical Markovian diffusion matrix leading to a Gibbs equilibrium state for a set of N coupled quantum harmonic oscillators are derived within Lindblad's axiomatic approach. Consequences of the fundamental constraints on the quantum friction coefficients are discussed. We derive the equations of motion for the expectation values and variances, and we solve them analytically. We apply our results to the description of the charge and mass asymmetry coordinates in heavy-ion collisions, and we investigate the effect of dissipation on tunneling in sub-barrier processes.The elements of the quantum mechanical Markovian diffusion matrix leading to a Gibbs equilibrium state for a set of N coupled quantum harmonic oscillators are derived within Lindblad's axiomatic approach. Consequences of the fundamental constraints on the quantum friction coefficients are discussed. We derive the equations of motion for the expectation values and variances, and we solve them analytically. We apply our results to the description of the charge and mass asymmetry coordinates in heavy-ion collisions, and we investigate the effect of dissipation on tunneling in sub-barrier processes.

arXiv:1005.4185Journal of Physics G Nuclear and Particle PhysicsNov 12, 201010 citations

Coordinate-dependent diffusion coefficients: Decay rate in open quantum systems

Vazgen Valerikovich Sargsyan, Yu. V. Palchikov, Z. Kanokov +2 more

Based on a master equation for the reduced density matrix of an open quantum collective system, the influence of coordinate-dependent microscopical diffusion coefficients on the decay rate from a metastable state is treated. For various frictions and temperatures larger than a crossover temperature, the quasistationary decay rates obtained with the coordinate-dependent microscopical set of diffusion coefficients are compared with those obtained with the coordinate-independent microscopical set of diffusion coefficients and coordinate-independent and -dependent phenomenological sets of diffusion coefficients. Neglecting the coordinate dependence of diffusion coefficients, one can strongly overestimate or underestimate the decay rate at low temperature. The coordinate-dependent phenomenological diffusion coefficient in momentum are shown to be suitable for applications.Based on a master equation for the reduced density matrix of an open quantum collective system, the influence of coordinate-dependent microscopical diffusion coefficients on the decay rate from a metastable state is treated. For various frictions and temperatures larger than a crossover temperature, the quasistationary decay rates obtained with the coordinate-dependent microscopical set of diffusion coefficients are compared with those obtained with the coordinate-independent microscopical set of diffusion coefficients and coordinate-independent and -dependent phenomenological sets of diffusion coefficients. Neglecting the coordinate dependence of diffusion coefficients, one can strongly overestimate or underestimate the decay rate at low temperature. The coordinate-dependent phenomenological diffusion coefficient in momentum are shown to be suitable for applications.

Physical Review AJun 22, 200724 citations

Quantum-statistical equation of motion for non-equilibrium processes

Ralf Der, Reinhold Haberlandt

Physics Letters AAug 1, 19744 citations

Density Matrix Formalism for Interacting Quantum Fields

Christian Käding, Mario Pitschmann

We provide a description of interacting quantum fields in terms of density matrices for any occupation numbers in Fock space in a momentum basis. As a simple example, we focus on a real scalar field interacting with another real scalar field, and present a practicable formalism for directly computing the density matrix elements of the combined scalar–scalar system. For deriving the main formula, we use techniques from non-equilibrium quantum field theory like thermo-field dynamics and the Schwinger–Keldysh formalism. Our results allow for studies of particle creation/annihilation processes at finite times and other non-equilibrium processes, including those found in the theory of open quantum systems.We provide a description of interacting quantum fields in terms of density matrices for any occupation numbers in Fock space in a momentum basis. As a simple example, we focus on a real scalar field interacting with another real scalar field, and present a practicable formalism for directly computing the density matrix elements of the combined scalar–scalar system. For deriving the main formula, we use techniques from non-equilibrium quantum field theory like thermo-field dynamics and the Schwinger–Keldysh formalism. Our results allow for studies of particle creation/annihilation processes at finite times and other non-equilibrium processes, including those found in the theory of open quantum systems.

arXiv:2210.06991UniverseNov 16, 202211 citations

Density Matrix Methods for Quantum Transport

Andrea Donarini, Milena Grifoni

Lecture notes in physicsJan 1, 20240 citations

Diffusion coefficients in coordinate in density matrix description of non-equilibrium quantum processes

Related papers

Diffusion coefficients in coordinate in density matrix description of non-equilibrium quantum processes

Related papers