Dissipative phase transition in a spatially-correlated bosonic bath

TL;DR

This paper investigates how a spatially-correlated bosonic bath can induce a first-order dissipative phase transition in a system of atoms, with behavior dependent on temperature and symmetry considerations.

Contribution

It reveals a temperature-dependent transition from non-thermalized to thermalized states driven by bath correlations and symmetry breaking.

Findings

At zero temperature, the bath acts as a common environment preventing thermalization.

A first-order dissipative phase transition occurs as temperature increases.

Symmetries at zero temperature are broken at finite temperature, leading to the phase transition.

Abstract

The presence of symmetries in a closed many-body quantum system results in integrability. For such integrable systems, complete thermalization does not occur. As a result, the system remains non-ergodic. On the other hand, a set of non-interacting atoms connected to a regular bosonic bath thermalizes. Here, we show that such atoms in a spatially-correlated thermal bath can show both the behavior depending on the temperature. At zero temperature, the bath has a large correlation length, and hence it acts as a common environment. In this condition, a set of weak symmetries exist, which prevent thermalization. The system undergoes a symmetry-broken dissipative phase transition of the first order as the temperature rises above zero.