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

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 ζ≠ζ(loc)≠ζ(s) and ζ(loc)≠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.