Vortex-lattice dynamics with channeled pinning potential landscapes

We have studied vortex-lattice dynamics as a function of driving force direction, in superconducting Nb films with periodic pinning arrays of magnetic dots. Square and rectangular symmetry arrays define channels that guide the vortex-lattice motion. We investigated the effect of the driving force direction on the commensurability between the vortex-lattice and dots array. We also studied the transverse depinning of the vortexlattice as is moving longitudinally along channels. We found that transverse depinning forces are enhanced with respect to the static situation. The results are discussed in terms of the dynamical evolution of order in the vortex-lattice.