Critical depinning force and vortex lattice order in disordered superconductors - art. no. 024518

We simulate the ordering of vortices and its effects on the critical curren t in superconductors with varied vortex-vortex interaction strength and var ied pinning strengths for a two-dimensional system. For strong pinning the vortex lattice is always disordered and the critical depinning force only w eakly increases with decreasing vortex-vortex interactions. For weak pinnin g the vortex lattice is defect-fret: until the vortex-vortex interactions h ave been reduced to a low value, when defects begin to appear with a simult aneous rapid increase in the critical depinning force. In each case the dep inning force shows a maximum for noninteracting vortices. The relative heig ht of the peak increases and the peak width decreases for decreasing pinnin g strength in agreement with experimental trends associated with the peak e ffect. We show that scaling relations exist between the distance between de fects in the vortex lattice and the critical depinning force.