Magnetism via superconductivity in SF proximity structures

TL;DR

This paper investigates how ferromagnetism can be induced in superconductors through proximity effects in superconductor-ferromagnet hybrid structures, revealing that magnetic correlations extend into the superconductor and depend on interface properties.

Contribution

It provides a theoretical analysis of magnetic proximity effects in SF structures using quasiclassical theory, highlighting the dependence on interface parameters and implications for mesoscopic hybrid properties.

Findings

Ferromagnetic correlations extend into the superconductor over the coherence length.

The extent of induced ferromagnetism depends on interface parameters.

Magnetic proximity effects can significantly influence mesoscopic SF hybrid properties.

Abstract

We consider the proximity effects in hybrid superconductor (S) - ferromagnet (F) structures drawing attention to the induced ferromagnetism of the S metal. The analysis is based on a quasiclassical theory of proximity effect for metals in the dirty limit conditions. It is shown that, below the superconducting critical temperature, ferromagnetic correlations extend a distance of order of the superconducting coherence length \xi_{S} into the superconductor, being dependent on the S/F interface parameters. We argue that the properties of mesoscopic SF hybrids may drastically depend upon the magnetic proximity effect, and recent experiments lend support to the model of SF structures where the superconducting and magnetic parameters are tightly coupled.