Impurity-induced diffusion bias in epitaxial growth

TL;DR

This paper introduces two impurity models in epitaxial growth, revealing how barrier-like impurities induce downhill currents with Edwards-Wilkinson scaling, while trap-like impurities maintain conserved-KPZ scaling, highlighting impurity effects on surface morphology.

Contribution

The paper presents two novel impurity interaction models in epitaxial growth, analyzing their effects on surface current and scaling behavior.

Findings

Barrier model causes downhill current and Edwards-Wilkinson scaling.

Trap model preserves symmetry and exhibits conserved-KPZ scaling.

Impurities significantly influence surface growth dynamics.

Abstract

We introduce two models for the action of impurities in epitaxial growth. In the first, the interaction between the diffusing adatoms and the impurities is ``barrier''-like and, in the second, it is ``trap''-like. For the barrier model, we find a symmetry breaking effect that leads to an overall down-hill current. As expected, such a current produces Edwards-Wilkinson scaling. For the trap model, no symmetry breaking occurs and the scaling behavior appears to be of the conserved-KPZ type.