Spin-dependent coupling of supercurrent and nonequilibrium quasiparticles in high-field superconductors

TL;DR

This paper experimentally explores how supercurrent and nonequilibrium quasiparticles interact in high-field superconductors, revealing spin-dependent effects predicted by theory, with implications for superconducting spintronics.

Contribution

It provides the first experimental evidence of spin-dependent coupling between supercurrent and quasiparticles in high magnetic fields in superconductors.

Findings

Supercurrent induces energy and charge imbalance coupling at low temperatures.

High magnetic fields reveal spin-dependent coupling effects.

Evidence supports recent theoretical predictions of spin-dependent interactions.

Abstract

We report on an experimental investigation of the combined effect of nonequilibrium quasiparticle injection and supercurrent in superconducting aluminum wires. At low temperature, we observe the supercurrent-induced coupling of energy and charge imbalance with spectral resolution. At high magnetic fields, in the presence of a Zeeman splitting of the density of states, we find evidence for an additional spin-dependent coupling which has been recently predicted theoretically.