Long Range Correlations in the Disordered Phase of a Simple Three State Lattice Gas

TL;DR

This paper studies a three-state lattice gas with charged particles under an electric field, revealing long-range correlations and complex crossover behaviors in the disordered phase through simulations and Langevin analysis.

Contribution

It introduces a detailed analysis of long-range correlations in a driven three-state lattice gas, combining Langevin equations and Monte Carlo simulations to uncover new crossover phenomena.

Findings

Discontinuity singularity in structure factors at the origin.

Complex crossover between different power-law correlations.

Stable homogeneous disordered phase with long-range correlations.

Abstract

We investigate the dynamics of a three-state stochastic lattice gas, consisting of holes and two oppositely "charged" species of particles, under the influence of an "electric" field, at zero total charge. Interacting only through an excluded volume constraint, particles can hop to nearest neighbour empty sites. With increasing density and drive, the system orders into a charge-segregated state. Using a combination of Langevin equations and Monte Carlo simulations, we study the steady-state structure factors in the disordered phase where homogeneous configurations are stable against small harmonic perturbations. They show a discontinuity singularity at the origin which in real space leads to an intricate crossover between power laws of different kinds.