Field-driven solid-on-solid interfaces moving under a stochastic Arrhenius dynamic: effects of the barrier height

TL;DR

This paper combines analytical methods and kinetic Monte Carlo simulations to study how the microscopic structure and mobility of solid-on-solid interfaces are affected by an external driving force and the energy barrier in a stochastic Arrhenius dynamic.

Contribution

It provides new analytical and simulation insights into the effects of barrier height on interface structure and dynamics under non-equilibrium conditions.

Findings

Higher energy barriers lead to decreased local interface width.

Skewness of the interface increases with barrier height.

Interface velocity and step height depend on driving force and barrier height.

Abstract

We present analytical results and kinetic Monte Carlo simulations for the mobility and microscopic structure of solid-on-solid (SOS) interfaces driven far from equilibrium by an external force, such as an applied field or (electro)chemical potential difference. The interfaces evolve under a specific stochastic dynamic with a local energy barrier (an Arrhenius dynamic), known as the transition dynamics approximation (TDA). We calculate the average height of steps on the interface, the average interface velocity, and the skewness of the interface as functions of the driving force and the height of the energy barrier. We find that the microscopic interface structure depends quite strongly on the barrier height. As the barrier becomes higher, the local interface width decreases and the skewness increases, suggesting increasing short-range correlations between the step heights.