Locking-unlocking transition of a two-dimensional lattice of superconducting vortices

Abstract At a temperature T u c a two-dimensional lattice of superconducting vortices interacting with a periodic pinning potential is found to undergo a transition from a registered locked phase (T u ) to a floating unlocked phase (T > T u ). A simple model accounts for the main features of the transition observed in thickness-modulated superconducting films.