High temperature expansion for a driven bilayer system

TL;DR

This paper develops a high temperature expansion method for analyzing non-equilibrium steady states in a driven bilayer lattice gas, successfully capturing phase behavior and computing observable currents.

Contribution

It introduces a simple high temperature expansion technique directly from microscopic dynamics for non-equilibrium systems, providing analytical insights into phase diagrams and currents.

Findings

Captures phases observed in simulations

Estimates transition lines accurately

Computes particle and energy currents

Abstract

Based directly on the microscopic lattice dynamics, a simple high temperature expansion can be devised for non-equilibrium steady states. We apply this technique to investigate the disordered phase and the phase diagram for a driven bilayer lattice gas at half filling. Our approximation captures the phases first observed in simulations, provides estimates for the transition lines, and allows us to compute signature observables of non-equilibrium dynamics, namely, particle and energy currents. Its focus on non-universal quantities offers a useful analytic complement to field-theoretic approaches.