Numerical study on the dynamics of a driven disordered vortex lattice

Using a model of long-range interactions between vortices, we numerically i nvestigate the dynamics of a driven vortex lattice subject to the randomly distributed pointlike pinning centers in a thin superconducting film. At ze ro temperature, crossover from elastic to plastic depinnings is observed wi th increasing density of pinning centers. With the lattice softness, the sc aling fit between force and velocity obtained in the elastic regime becomes invalid when the plastic flow appears. The peak effect occurs when one ent ers the plastic regime and the lattice tearing first enhances the critical current density j(c) and then suppresses it. "Steps" in the curve of veloci ty-force dependence and its differential are also found in the plastic regi me. For the finite-temperature case, we see evidence of plastic and filamen tary flow at low driving forces and temperatures. At high driving forces an d low enough temperatures, evidence of an ordering of the moving vortices i s seen in the flux flow regime. Our results are in agreement with all the p revious simulations and recent experiments.