Thermal equilibrium of two quantum Brownian particles

TL;DR

This paper investigates how a thermal environment affects the equilibrium properties and entanglement of two quantum Brownian particles, revealing temperature-dependent entanglement behavior and the role of the environment in inducing interactions.

Contribution

It models the environment's influence on bipartite quantum systems, showing how temperature and spectral functions affect entanglement and system interactions.

Findings

Entanglement decreases monotonically with temperature.

Finite temperatures can still induce entanglement via the reservoir.

The model reproduces Brownian motion and effective interactions.

Abstract

The influence of the environment in the thermal equilibrium properties of a bipartite continuous variable quantum system is studied. The problem is treated within a system-plus-reservoir approach. The considered model reproduces the conventional Brownian motion when the two particles are far apart and induces an effective interaction between them, depending on the choice of the spectral function of the bath. The coupling between the system and the environment guarantees the translational invariance of the system in the absence of an external potential. The entanglement between the particles is measured by the logarithmic negativity, which is shown to monotonically decrease with the increase of the temperature. A range of finite temperatures is found in which entanglement is still induced by the reservoir.