Periodic Pinning Arrays Research Articles

Disorder effect on melting transitions of vortex lattices with periodic pinning

Employing molecular-dynamics simulations, we study the melting transitions in driven vortex lattices with commensurability between arrays of vortices and defects. It is shown that the largest pinning effect can be obtained for periodic pinning arrays at zero temperature, and either thermal fluctuation or disorder of pinning array plays a significant depinning role in the melting transitions of the driven vortex lattices. As the pinning sites deviate from the periodic array, the intervortex interaction is found to produce an additional depinning effect on driven vortex lattices. Furthermore, enough disorder will result in a crossover from a first-order melting transition to a continuous phase transition.