Kinetic Roughening in Surfaces of Crystals Growing on Disordered Substrates

TL;DR

This paper investigates how substrate disorder influences the scaling and roughening behavior of growing crystalline surfaces, revealing phase transitions, superrough phases, and complex dependencies on physical parameters.

Contribution

It introduces a harmonic approach to analyze substrate disorder effects and uncovers a phase transition to a superrough phase with a varying dynamic exponent.

Findings

Existence of a phase transition to a superrough phase with z>2

Disorder causes lattice effects to decay with a crossover behavior

Surface mobility depends complexly on temperature and physical parameters

Abstract

Substrate disorder effects on the scaling properties of growing crystalline surfaces in solidification or epitaxial deposition processes are investigated. Within the harmonic approach there is a phase transition into a low-temperature (low-noise) superrough phase with a continuously varying dynamic exponent z>2 and a non-linear response. In the presence of the KPZ nonlinearity the disorder causes the lattice efects to decay on large scales with an intermediate crossover behavior. The mobility of the rough surface hes a complex dependence on the temperature and the other physical parameters.