Vortex dynamics in regular arrays of asymmetric pinning centers - art. no.012504

Molecular-dynamics simulations of the current-voltage characteristics V(I) have been performed for regular arrays of asymmetric pinning centers modele d by the superposition of two interpenetrating square lattices of weak and strong pinning centers with separation Deltap. In this case, an applied Lor entz force F-L acts as a depinning force which is directed either from weak to strong pinning site or vice versa, depending on the polarity of F-L. Th is leads to a pronounced asymmetry of the current-voltage characteristics a nd of the critical currents I-c(F-L) and I-c(-F-L) ("vortex diode effect"). In addition to that, the F-L-Deltap phase diagram reveals a strong depende nce of the different dynamical vortex phases on the shift between the two p inning sublattices.