Spin-polarized quasiparticle transport in exchange-split superconducting aluminum on europium sulfide

TL;DR

This paper demonstrates that ferromagnetic insulators like europium sulfide can induce exchange splitting in superconducting aluminum, enabling control of spin transport and injection over long distances in superconductors.

Contribution

It shows for the first time that exchange-split superconductors can support long-range spin transport controlled by ferromagnetic insulators.

Findings

Spin injection observed in aluminum wires.

Long-range spin transport enabled by exchange splitting.

Control of spin currents via ferromagnetic insulators.

Abstract

We report on nonlocal spin transport in mesoscopic superconducting aluminum wires in contact with the ferromagnetic insulator europium sulfide. We find spin injection and long-range spin transport in the regime of the exchange splitting induced by europium sulfide. Our results demonstrate that spin transport in superconductors can be manipulated by ferromagnetic insulators, and opens a new path to control spin currents in superconductors.