Pinning and thermal fluctuation effects on the two-dimensional vortex lattice: a numerical study

Within the dynamic approach we investigate numerically the influence of pinning and thermal fluctuation effects on the motion of the two-dimensional (2D) vortex lattice under the action of an external driving force. At zero temperature the critical pinning force is found to increase with increasing density of pinning centers and with decreasing of the strength of vortex-vortex interaction. The crossover between elastic and plastic regimes is observed. For the finite temperature case, three regions with different behavior in the curve of velocity-force dependence (VFD) are observed; with increasing the temperature, the influence of pinning effects decreases, leading to a decrease of the critical pinning force and the restoration of the Linear VFD. (C) 1999 Elsevier Science B.V. All rights reserved.