Geometry dependent distribution of the supercurrent in YBa2Cu3O7-x films with patterned pinning landscape

TL;DR

This study investigates how patterned pinning landscapes created by heavy ion irradiation affect the distribution of supercurrent and vortex behavior in YBa2Cu3O7-x films, revealing geometry-dependent effects on vortex dynamics.

Contribution

It introduces a method to create localized, anisotropic pinning modulations in YBCO films and analyzes their impact on supercurrent and vortex behavior using magneto-optical techniques.

Findings

Different supercurrent distributions for perpendicular and parallel orientations.

Enhanced vortex diffusion in the perpendicular configuration.

Observation of vortex bundle jumps and Meissner volume compression.

Abstract

We created local pinning modulations in YBCO films by means of confined high energy heavy ion irradiation. The high energy of the ions allows us to introduce nanometric size defects with a well defined anisotropy. The dose was chosen in such a way to reduce the local critical current of the irradiated area. We used a quantitative magneto-optical analysis to measure the magnetic field vector and the supercurrent for each point of the whole sample surface. The basic geometry of a rectangular region inside strip-shaped samples was considered in order to investigate in detail the effect of the orientation of planar boundaries with respect to the supercurrent flow direction. Here we present the two complementary orientations of the modulated region, i.e., perpendicular and parallel to the main supercurrent flow. The comparison of the magnetic field and supercurrent distributions shows deep differences between the two configurations. In particular, the enhanced vortex diffusion, observed for the perpendicular case, was not found in the parallel configuration. In a such case, unexpected vortex bundle jumps and a Meissner volume compression are clearly observed after the vortices enter the irradiated region.