title: Creep motion of an elastic string in a random potential.
abstract: We study the creep motion of an elastic string in a two-dimensional pinning landscape by means of 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 mu and the roughness exponent zeta. Two regimes are identified: when the temperature is larger than the strength of the disorder, we find mu approximately 1/4 and zeta approximately 2/3, in agreement with the quasi-equilibrium-nucleation picture of creep motion; on the contrary, when lowering the temperature enough, the values of mu and zeta increase, showing a strong violation of the latter picture.
authors.affiliation: Université de Genéve, DPMC, 24 Quai Ernest Ansermet, CH-1211 Genéve 4, Switzerland.
authors.forename: Alejandro B
authors.initials: AB
authors.lastname: Kolton
authors.forename: Alberto
authors.initials: A
authors.lastname: Rosso
authors.forename: Thierry
authors.initials: T
authors.lastname: Giamarchi