Dynamical symmetry breaking and phase transitions in driven diffusive systems

TL;DR

This paper investigates phase transitions in driven diffusive systems by analyzing current fluctuations and large deviation functions, revealing conditions for symmetry-breaking and phase transition types with microscopic models and an exact Landau theory.

Contribution

It introduces conditions for phase transitions in diffusive systems, linking singularities in large deviation functions to symmetry-breaking and phase transition types, supported by microscopic models and an exact Landau theory.

Findings

Singularities in large deviation functions indicate phase transitions.

Transitions can be continuous or first-order depending on symmetry.

Microscopic models demonstrate the theoretical scenarios.

Abstract

We study the probability distribution of a current flowing through a diffusive system connected to a pair of reservoirs at its two ends. Sufficient conditions for the occurrence of a host of possible phase transitions both in and out of equilibrium are derived. These transitions manifest themselves as singularities in the large deviation function, resulting in enhanced current fluctuations. Microscopic models which implement each of the scenarios are presented, with possible experimental realizations. Depending on the model, the singularity is associated either with a particle-hole symmetry breaking, which leads to a continuous transition, or in the absence of the symmetry with a first-order phase transition. An exact Landau theory which captures the different singular behaviors is derived.