Laterally driven interfaces in the three-dimensional Ising lattice gas

TL;DR

This study uses computer simulations to analyze how lateral driving forces affect the interface properties of a three-dimensional Ising lattice gas, revealing suppression of fluctuations and altered correlations under shear-like drives.

Contribution

It introduces a detailed simulation analysis of lateral driving effects on 3D Ising lattice gas interfaces, extending previous 2D findings and exploring different driving force profiles.

Findings

Shear-like drive suppresses capillary-wave fluctuations.

Sharper magnetisation profiles observed under drive.

Lateral transport of capillary waves occurs with odd current functions.

Abstract

We study the steady state of a phase-separated driven Ising lattice gas in three dimensions using computer simulations with Kawasaki dynamics. An external force field F(z) acts in the x direction parallel to the interface, creating a lateral order parameter current j^x(z) which varies with distance z from the interface. Above the roughening temperature, our data for `shear-like' linear variation of F(z) are in agreement with the picture wherein shear acts as effective confinement in this system, thus supressing the interfacial capillary-wave fluctuations. We find sharper magnetisation profiles and reduced interfacial width as compared to equilibrium. Pair correlations are more suppressed in the vorticity direction y than in the driving direction; the opposite holds for the structure factor. Lateral transport of capillary waves occurs for those forms of F(z) for which the current j^x(z) is an odd function of z, for example the shear-like drive, and a `step-like' driving field. For a V-shaped driving force no such motion occurs, but capillary waves are suppressed more strongly than for the shear-like drive. These findings are in agreement with our previous simulation studies in two dimensions. Near and below the (equilibrium) roughening temperature the effective-confinement picture ceases to work, but the lateral motion of the interface persists.