Driven Diffusive Systems: How Steady States Depend on Dynamics

TL;DR

This paper demonstrates through simulations that non-equilibrium steady states in driven systems are significantly influenced by the choice of dynamics, affecting correlations and thermodynamic properties.

Contribution

It provides a comparative analysis of different Monte Carlo dynamics on non-equilibrium steady states, highlighting their impact on observable quantities.

Findings

Heat bath and Glauber rates produce similar data

Metropolis rates result in weaker correlations

The ratio related to the Boltzmann factor depends on dynamics

Abstract

In contrast to equilibrium systems, non-equilibrium steady states depend explicitly on the underlying dynamics. Using Monte Carlo simulations with Metropolis, Glauber and heat bath rates, we illustrate this expectation for an Ising lattice gas, driven far from equilibrium by an `electric' field. While heat bath and Glauber rates generate essentially identical data for structure factors and two-point correlations, Metropolis rates give noticeably weaker correlations, as if the `effective' temperature were higher in the latter case. We also measure energy histograms and define a simple ratio which is exactly known and closely related to the Boltzmann factor for the equilibrium case. For the driven system, the ratio probes a thermodynamic derivative which is found to be dependent on dynamics.