Depinning phase transition in two-dimensional clock model with quenched randomness

TL;DR

This study uses Monte Carlo simulations to analyze the depinning phase transition in a two-dimensional driven random-field clock model, revealing how disorder and initial conditions influence critical behavior.

Contribution

It introduces a systematic analysis of how the form and strength of quenched randomness affect critical exponents and interface roughening in the model.

Findings

Critical exponents vary with random-field distribution and strength.

The interface roughening dynamics belong to a new subclass with unique roughness exponents.

Transition field and critical exponents depend on initial magnetization orientations.

Abstract

With Monte Carlo simulations, we systematically investigate the depinning phase transition in the two-dimensional driven random-field clock model. Based on the short-time dynamic approach, we determine the transition field and critical exponents. The results show that the critical exponents vary with the form of the random-field distribution and the strength of the random fields, and the roughening dynamics of the domain interface belongs to the new subclass with $\zeta \neq \zeta_{loc} \neq \zeta_s$ and $\zeta_{loc} \neq 1$. More importantly, we find that the transition field and critical exponents change with the initial orientations of the magnetization of the two ordered domains.