Controllable manipulation of superconductivity using magnetic vortices

TL;DR

This paper demonstrates how magnetic vortices in a hybrid superconductor/ferromagnet structure can be used to controllably manipulate the superconducting state through magnetic history and vortex configurations.

Contribution

It introduces a method to control superconductivity using magnetic vortex states in a hybrid structure, revealing strong coupling effects and magnetic history dependence.

Findings

Magnetic vortex states can induce normal or superconducting phases in the superconductor.

Superconducting properties can be reversibly controlled by magnetic history.

Ferromagnetic hysteresis effects are transferred to superconducting transport properties.

Abstract

The magneto-transport of a superconducting/ferromagnetic hybrid structure consisting of a superconducting thin film in contact with an array of magnetic nanodots in the so-called "magnetic vortex-state" exhibits interesting properties. For certain magnetic states, the stray magnetic field from the vortex array is intense enough to drive the superconducting film into the normal state. In this fashion, the normal-to-superconducting phase transition can be controlled by the magnetic history. The strong coupling between superconducting and magnetic subsystems allows characteristically ferromagnetic properties, such as hysteresis and remanence, to be dramatically transferred into the transport properties of the superconductor.