Critical current suppression in [formula omitted] superconductors and its dependence on the defects concentration

Abstract

For the first time, we have calculated the dependence of the critical current density j c on the defects concentration n d in a system simulating a HTSC layer. It was shown that j c ( n d ) dependence is non-monotonic and has a peak at the optimal concentration of defects n opt which is consistent with the known experimental data. We conclude that collective depinning—the reduction of effective pinning potential caused by increase of defects concentration—is the main mechanism for saturation and the subsequent decrease of j c .