Self-healing patterns in ferromagnetic-superconducting hybrids

摘要

We study magnetic flux dynamic effects in a superconducting (SC) bridge with thin soft magnetic stripes placed either on top or under the bridge. Voltage-current (VI) measurements reveal that the edges of magnetic stripes oriented transvers or along the bridge introduce channels or barriers for vortex motion, resulting in the decrease or increase of the critical current, respectively. We propose a self-healing mechanism for the hybrid with longitudinal stripes whereby the magnetic pinning strength increases with current. The self-field of the current polarizes the magnetic stripes across their length, which enhances the stray fields at their long edges and creates a dynamic vortex pinning landscape to impede vortex flow. We show a qualitative confirmation of the proposed mechanism which offers new strategies to engineer adaptive pinning topologies in SC-ferromagnetic hybrids.