Crystal surfaces with correlated disorder: Phase transitions between roughening and superroughening

TL;DR

This paper develops a theoretical framework using dynamical functional renormalization group to analyze phase transitions in crystal surfaces with correlated disorder, revealing how disorder correlation range influences roughening behaviors.

Contribution

It introduces a novel approach to treat arbitrary disorder correlations in surface transition theory, connecting roughening and superroughening transitions.

Findings

Roughening transition becomes continuous with decreasing disorder correlation range.

The theory applies to random-field XY-models and vortex glasses.

Disorder correlation range critically affects surface roughness behavior.

Abstract

A theory for surface transitions in the presence of a disordered pinning potential is presented. Arbitrary disorder correlations are treated in the framework of a dynamical functional renormalization group. The roughening transition, where surface roughness and mobility behave discontinuously, is shown to turn smoothly into the continuous superroughening transition, when the range of disorder correlations is decreased. Implications for random-field $XY$-models and vortex glasses are discussed.