Interplay between the vortex lattice and arrays of submicrometric pinning centers

Ordered arrays of submicrometric magnetic pinning centers have been fabricated in superconducting Nb films by electron beam lithography. Periodic pinning effects, observed when the vortex lattice matches the array of dots, have been studied as a function of temperature, current and array geometry in order to analyze the physics of the interaction between the vortex lattice and the periodic array of microscopic pinning centers. These results have allowed pointing to the magnetic origin of the relevant pinning mechanism in this system and to dynamic ordering effects of the vortex lattices. The effect of the relative direction of the driving force with respect to the pinning potential is dependent on the anisotropy configuration of the artificial submicrometric array.