Anisotropic vortex pinning in superconductors with a square array of rectangular submicron holes

TL;DR

This study explores how rectangular submicron holes in superconducting films create anisotropic vortex pinning, affecting the critical current depending on the current's direction, with implications for superconductor performance.

Contribution

It demonstrates the anisotropic vortex pinning effects in superconductors with rectangular antidots, comparing fully perforating and blind antidots, revealing directional dependence of critical current.

Findings

Higher critical current when current is along the long side of antidots

Sharper IV-transition along the long side

Distinct anisotropic pinning observed in both antidot types

Abstract

We investigate vortex pinning in thin superconducting films with a square array of rectangular submicron holes ("antidots"). Two types of antidots are considered: antidots fully perforating the superconducting film, and "blind antidots", holes that perforate the film only up to a certain depth. In both systems, we observe a distinct anisotropy in the pinning properties, reflected in the critical current Ic, depending on the direction of the applied electrical current: parallel to the long side of the antidots or perpendicular to it. Although the mechanism responsible for the effect is very different in the two systems, they both show a higher critical current and a sharper IV-transition when the current is applied along the long side of the rectangular antidots.