Long-Range Order in a Quasi One-Dimensional Non-Equilibrium Three-State Lattice Gas

TL;DR

This paper investigates a quasi one-dimensional lattice gas with two species undergoing biased diffusion, revealing unexpected phase separation and macroscopic clustering in steady state through Monte Carlo simulations.

Contribution

It demonstrates that a quasi one-dimensional model exhibits phase separation, unlike its simpler one-dimensional counterpart, highlighting new non-equilibrium phenomena.

Findings

Phase separation occurs in the steady state.

Macroscopic particle clusters form.

Order parameter and cluster-size distributions support the phase separation.

Abstract

Biased diffusion of two species with conserved dynamics on a 2xL periodic lattice is studied via Monte Carlo simulations. In contrast to its simple one-dimensional version on a ring, this quasi one-dimensional model surprisingly exhibits phase separation in its steady state, which is characterized by one macroscopic particle cluster. We study the order parameter and the cluster-size distributions as a function of the system size L, to support the above picture.