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

TL;DR

This study investigates how random removal of pinning sites in Nb thin films with triangular antidot arrays affects dissipation, revealing that disorder can enhance the depinning current and reduce flux-flow voltage near the transition temperature.

Contribution

It demonstrates that introducing disorder into periodic pinning arrays enhances the depinning current and suppresses dissipation in Nb thin films.

Findings

Increased antidot dilution raises the depinning current Ic.

Disorder reduces flux-flow voltage for magnetic fields above a certain threshold.

Results confirm theoretical predictions about disorder effects in pinning arrays.

Abstract

The depinning current Ic versus applied magnetic field B close to the transition temperature Tc of Nb thin films with randomly diluted triangular arrays of antidots is investigated. % Our experiments confirm essential features in Ic(B) as predicted by Reichhardt and Olson Reichhardt [Phys.Rev. B 76, 094512 (2007)]. % We show that, by introducing disorder into periodic pinning arrays, Ic can be enhanced. % In particular, for arrays with fixed density n_p of antidots, an increase in dilution Pd induces an increase in Ic and decrease of the flux-flow voltage for B>Bp=n_p Phi_0.