Generating strong magnetic flux shielding regions in a single crystal of Bi2Sr2CaCu2O8 using a blind hole array

TL;DR

This study demonstrates that a hexagonal array of blind holes in a Bi2Sr2CaCu2O8 crystal creates a flux shielding region with enhanced penetration field, effectively preventing vortex entry and maintaining a flux-free state.

Contribution

It introduces a novel nanopatterning technique to generate strong magnetic flux shielding regions in high-temperature superconductor crystals.

Findings

Patterned region shows enhanced local magnetization response.

Penetration field in the patterned area is increased by a factor of three.

Shielding currents create a barrier preventing vortex entry.

Abstract

Magneto-optical imaging studies in a single crystal of Bi2Sr2CaCu2O8 partially patterned with a hexagonal array of pinning centers (blind holes) reveals local features in the patterned region which are distinct compared to the pristine unpatterned regions in the sample. The patterned area exhibits a strongly diamagnetic local magnetization response and is characterized by a local penetration field enhanced by a factor of three. We show that strong shielding currents around the periphery of the nanopatterned region create a barrier which prevents vortex entry into the patterned region thus sustaining an effectively flux-free state upto the enhanced penetration field.