Superconducting Vortex Dynamics in Thin Films Near the Critical Temperature

During a field cool, superconducting vortices remain mobile only within a narrow temperature range above the vortex freezing temperature, where the vortex dynamics are mainly defined by the interplay between repulsive vortex-vortex and attractive vortex-defect interactions. Below the vortex freezing temperature, vortex pinning by defects becomes so strong that neither vortex-vortex interaction nor thermal activation are able to move the vortex. We study this process by modeling the pinning landscape as a double well potential arising from two defects and examining the time evolution of the probability density of the vortex position. We consider the Pearl limit where the film thickness is much smaller than the bulk penetration depth, which causes long range vortex-defect interactions. Our results show that even a simple model accounting for a single vortex can shed a light onto vortex distributions among defects in superconductors.