A superconducting absolute spin valve

TL;DR

This paper reports the first switchable superconducting spin-valve using EuS/Al bilayers, demonstrating a significant resistance change and potential applications in cryogenic superconducting spintronics and thermoelectric detectors.

Contribution

It presents the first experimental realization of a superconducting absolute spin-valve based on EuS/Al bilayers with tunable magnetizations.

Findings

Resistance change of up to 900% between parallel and antiparallel states.

Demonstration of highly spin-polarized currents through the junction.

Potential applications in superconducting spintronics and cryogenic detectors.

Abstract

A superconductor with a spin-split excitation spectrum behaves as an ideal ferromagnetic spin-injector in a tunneling junction. It was theoretical predicted that the combination of two such spin-split superconductors with independently tunable magnetizations, may be used as an ideal $absolute$ spin-valve. Here we report on the first switchable superconducting spin-valve based on two EuS/Al bilayers coupled through an aluminum oxide tunnel barrier. The spin-valve shows a relative resistance change between the parallel and antiparallel configuration of the EuS layers up to 900% that demonstrates a highly spin-polarized currents through the junction. Our device may be pivotal for realization of thermoelectric radiation detectors, logical element for a memory cell in cryogenics superconductor-based computers and superconducting spintronics in general.