Localization of superconductivity in superconductor-electromagnet hybrids

TL;DR

This paper explores how inhomogeneous magnetic fields from a Nb wire can localize and control superconductivity in an Al strip, demonstrating reversible displacement of the superconducting order parameter near the phase boundary.

Contribution

It introduces a method to controllably localize and manipulate superconductivity in hybrid structures using inhomogeneous magnetic fields.

Findings

Localized superconductivity can be achieved and displaced reversibly.

External magnetic fields modulate the position of the superconducting order parameter.

The inhomogeneous magnetic field creates a spatial modulation of T_c.

Abstract

We investigate the nucleation of superconductivity in a superconducting Al strip under the influence of the magnetic field generated by a current-carrying Nb wire, perpendicularly oriented and located underneath the strip. The inhomogeneous magnetic field, induced by the Nb wire, produces a spatial modulation of the critical temperature T_c, leading to a controllable localization of the superconducting order parameter (OP) wave function. We demonstrate that close to the phase boundary T_c(B_ext) the localized OP solution can be displaced reversibly by either applying an external perpendicular magnetic field B_ext or by changing the amplitude of the inhomogeneous field.