Enhancing the effective critical current density in a Nb superconducting thin film by cooling in an inhomogeneous magnetic field

Abstract

Quantitative magneto-optical imaging of a type-II superconductor thin film cooled under zero, homogeneous, and inhomogeneous applied magnetic fields, indicates that the latter procedure leads to an enhancement of the screening capacity. Such an observation is corroborated by both B-independent and B-dependent critical state model analyses. Furthermore, repulsive (attractive) vortex-(anti)vortex interactions were found to have a decisive role in the shielding ability, with initial states prepared with vortices resulting in a shorter magnetic flux front penetration depth than those prepared with antivortices. The proposed strategy could be implemented to boost the performance of thin superconducting devices.

6 pages and 5 figures

References in corpus (4)

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• Enhanced pinning and proliferation of matching effects in a superconducting film with a Penrose array of magnetic dots
• Magnetic flux pinning in superconductors with hyperbolic-tesselation arrays of pinning sites
• Magnetic confinement of the superconducting condensate in superconductor/ferromagnet hybrid composites