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

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 screening capacity. Such observation is corroborated by both B-independent B-dependent critical state model analyses. Furthermore, repulsive (attractive) vortex-(anti)vortex interactions were found have decisive role in shielding ability, with initial states prepared vortices resulting shorter flux front penetration depth than those antivortices. The proposed strategy could be implemented boost performance superconducting devices.