Entropy production and its large deviations in an active lattice gas

TL;DR

This paper analytically investigates the entropy production statistics in an active lattice gas model, revealing a complex phase diagram with multiple phase transitions and a novel tricritical point under bias.

Contribution

It provides the first analytical results for entropy production large deviations in an active lattice model, uncovering a rich phase structure with multiple nonequilibrium phase transitions.

Findings

Identification of five distinct phases under bias

Discovery of a bias-induced tricritical point

Analytical characterization of entropy production statistics

Abstract

Active systems are characterized by a continuous production of entropy at steady state. We study the statistics of entropy production within a lattice-based model of interacting active particles that is capable of motility-induced phase separation. Exploiting a recent formulation of the exact fluctuating hydrodynamics for this model, we provide analytical results for its entropy production statistics in both typical and atypical (biased) regimes. This complements previous studies of the large deviation statistics of entropy production in off-lattice active particle models that could only be addressed numerically. Our analysis uncovers an unexpectedly intricate phase diagram, with five different phases arising (under bias) within the parameter regime where the unbiased system is in its homogeneous state. Notably, we find the concurrence of first order and second order nonequilibrium phase transition curves at a bias-induced tricritical point, a feature not yet reported in previous studies of active systems.