Field-induced vacancy localization in a driven lattice gas: Scaling of steady states

TL;DR

This study uses simulations and mean-field theory to analyze how a single vacancy causes charge segregation and localization at interfaces in a driven lattice gas, revealing scaling behaviors influenced by system size, field strength, and lattice spacing.

Contribution

It introduces a combined simulation and mean-field approach to understand vacancy-induced charge segregation and interface localization in a driven lattice gas.

Findings

Vacancy localizes at interfaces exhibiting charge segregation.

Charge and hole density profiles scale with system size and field strength.

Lattice spacing significantly influences the steady-state structures.

Abstract

With the help of Monte Carlo simulations and a mean-field theory, we investigate the ordered steady-state structures resulting from the motion of a single vacancy on a periodic lattice which is filled with two species of oppositely ``charged'' particles. An external field biases particle-vacancy exchanges according to the particle's charge, subject to an excluded volume constraint. The steady state exhibits charge segregation, and the vacancy is localized at one of the two characteristic interfaces. Charge and hole density profiles, an appropriate order parameter and the interfacial regions themselves exhibit characteristic scaling properties with system size and field strength. The lattice spacing is found to play a significant role within the mean-field theory.