Creep motion of an elastic string in a random potential
arXiv:cond-mat/0408284 · doi:10.1103/PhysRevLett.94.047002
Abstract
We study the creep motion of an elastic string in a two dimensional pinning landscape by Langevin dynamics simulations. We find that the Velocity-Force characteristics are well described by the creep formula predicted from phenomenological scaling arguments. We analyze the creep exponent , and the roughness exponent . Two regimes are identified: when the temperature is larger than the strength of the disorder we find and , in agreement with the quasi-equilibrium-nucleation picture of creep motion; on the contrary, lowering enough the temperature, the values of and increase showing a strong violation of the latter picture.
4 pages, 3 figures