Механизм формирования критического тока высокотемпературных сверхпроводников, содержащих сквозные микроскопические дефекты

Abstract

The critical current of a model high-temperature superconductor (HTSC) with defects in the form of through holes (antidots) with a characteristic size greater than or of the order of the penetration depth of the magnetic field is calculated. To do this, the subprocesses equivalent to the trapping of the magnetic flux by the hole and the creation of a vortex at the edge of the hole are introduced into the model of layered HTSC. It is shown that accounting for these subprocesses leads to the appearance of a physical mechanism that allows us to correctly describe the non-monotonic dependence of the critical current on the characteristic size of the antidot, similar to that observed in the experiment. Calculations were performed for a pure superconductor and a superconductor containing nanoscale pinning centers. It is shown that the presence of nanoscale pinning centers along with antipoints does not change the qualitative picture of the influence of the antidot radius on the pinning character of the magnetic flux and the behavior of the critical current in the HTSC.