Inequivalence of Dynamical Ensembles in a Generalised Driven Diffusive Lattice Gas

TL;DR

This paper demonstrates that the equivalence of ensembles in equilibrium systems does not extend to a generalized driven diffusive lattice gas with combined Kawasaki and Glauber dynamics, highlighting fundamental differences in nonequilibrium statistical mechanics.

Contribution

It introduces a generalized DDLG model with mixed dynamics and shows, through simulations and perturbation analysis, that ensemble equivalence fails in this nonequilibrium setting.

Findings

Ensemble equivalence breaks down in the generalized model.

Monte Carlo simulations confirm non-equivalence.

Perturbation studies support the simulation results.

Abstract

We generalise the Driven Diffusive Lattice Gas (DDLG) model by using a combination of Kawasaki and Glauber dynamics. We find via Monte Carlo simulations and perturbation studies that the simplest possible generalisation of the equivalence of the canonical and grand-canonical ensembles, which holds in equilibrium, does not apply for this class of nonequilibrium systems.