1204.0772 (S. Bustingorry et al.)

Thermal rounding exponent of the depinning transition of an elastic
string in a random medium    [PDF]

S. Bustingorry, A. B. Kolton, T. Giamarchi

We study numerically thermal effects at the depinning transition of an elastic string driven in a two-dimensional uncorrelated disorder potential. The velocity of the string exactly at the sample critical force is shown to behave as $V \sim T^\psi$, with $\psi$ the thermal rounding exponent. We show that the computed value of the thermal rounding exponent, $\psi = 0.15$, is robust and accounts for the different scaling properties of several observables both in the steady-state and in the transient relaxation to the steady-state. In particular, we show the compatibility of the thermal rounding exponent with the scaling properties of the steady-state structure factor, the universal short-time dynamics of the transient velocity at the sample critical force, and the velocity scaling function describing the joint dependence of the steady-state velocity on the external drive and temperature.

View original: http://arxiv.org/abs/1204.0772