Suppression of dissipation in Nb thin films with triangular antidot arrays by random removal of pinning sites

摘要

The depinning current I-c. versus applied magnetic field B close to the transition temperature T_c of Nb thin films with randomly diluted triangular arrays of antidots is investigated. Our experiments confirm essential features in I_c(B) as predicted by Reichhardt and Olson Reichhardt [Phys. Rev. B 76, 094512 (2007)]. We show that, by introducing disorder into periodic pinning arrays, I_c can be enhanced. In particular, for arrays with fixed density n_p of antidots, an increase in dilution P_d induces an increase in I_c and decrease of the flux-flow voltage for B >B_p=n_pΦ_0.