Commensurability effects in superconducting Nb films with quasiperiodic pinning arrays

We study experimentally the critical depinning current I-c versus applied magnetic field B in Nb thin films which contain 2D arrays of circular antidots placed on the nodes of quasiperiodic (QP) fivefold Penrose lattices. Close to the transition temperature T-c we observe matching of the vortex lattice with the QP pinning array, confirming essential features in the I-c(B) patterns as predicted by Misko et al. [Phys. Rev. Lett. 95, 177007 (2005)]. We find a significant enhancement in I-c(B) for QP pinning arrays in comparison to I-c in samples with randomly distributed antidots or no antidots.