White Noise and Heating of Open Quantum Field Fermi Systems

TL;DR

This paper investigates how classical external Fermi fields influence the thermalization and particle densities in open quantum Fermi systems, revealing linear time evolution and particle-antiparticle pair creation effects.

Contribution

It introduces a model for the time evolution of density matrices in Fermi systems interacting with classical Fermi fields, highlighting the effects on temperature and particle density changes.

Findings

Linear time dependence of particle densities during thermalization

Particle-antiparticle pair creation for relativistic Dirac fermions

Independent mode variations in the system's response

Abstract

I study the time evolution of the density matrices of quantum Fermi systems interacting with classic external Fermi fields. This interaction either changes the temperature of the system or it affects the density of particles. For relativistic Dirac fermions, variations of temperature lead to creation (annihilation) of particle - antiparticle pairs. The change of the density (or of the chemical potential) indicates the existence of the incoming (outgoing) flux of fermions from (to) the bath. These changes are independent for the different modes and in order to model the thermalization one should adjust the spectrum of the noise. The linear time dependences of the densities of particles are characteristic for all the processes.