Quantum thermalization and vanishing thermal entanglement in the open Jaynes-Cummings model

TL;DR

This paper investigates how the Jaynes-Cummings model reaches thermal equilibrium in open systems and discovers a surprising loss of thermal entanglement under certain conditions.

Contribution

It provides a comprehensive analysis of thermalization conditions in the JC model and reveals the counterintuitive phenomenon of vanishing thermal entanglement.

Findings

Thermalization occurs only when heat baths have equal temperature or coupling is turned off.

In common heat bath, the JC system thermalizes regardless of bath parameters.

Thermal entanglement can vanish unexpectedly in the JC system.

Abstract

The quantum thermalization of the Jaynes-Cummings (JC) model in both equilibrium and non-equilibrium open-system cases is sdudied, in which the two subsystems, a two-level system and a single-mode bosonic field, are in contact with either two individual heat baths or a common heat bath. It is found that in the individual heat-bath case, the JC model can only be thermalized when either the two heat baths have the same temperature or the coupling of the JC system to one of the two baths is turned off. In the common heat-bath case, the JC system can be thermalized irrespective of the bath temperature and the system-bath coupling strengths. The thermal entanglement in this system is also studied. A \emph{counterintuitive} phenomenon of \emph{vanishing} thermal entanglement in the JC system is found and proved.