Long-range spin and charge accumulation in mesoscopic superconductors with Zeeman splitting

TL;DR

This paper models non-local spin and charge transport in a Zeeman-split superconducting wire, revealing long-range accumulations influenced by spin relaxation mechanisms and magnetic field effects, aligning with recent experimental observations.

Contribution

It introduces a comprehensive model accounting for Zeeman splitting and various relaxation mechanisms to explain long-range spin and charge accumulations in superconductors.

Findings

Long-range spin and charge accumulations are observed due to Zeeman splitting.

The non-local signal strongly depends on orbital depairing effects.

The model aligns with recent experimental results using realistic parameters.

Abstract

We describe the far from equilibrium non-local transport in a diffusive superconducting wire with a Zeeman splitting, taking into account the different spin relaxation mechanisms. We demonstrate that due to the Zeeman splitting an injection of a current in a superconducting wire creates a spin accumulation that can only relax via thermalization. In addition the Zeeman splitting also causes a suppression of the spin-orbit and spin-flip scattering rates. These two effects lead to long-range spin and charge accumulations detectable in the non-local signal. Our model explains the main qualitative features of recent experimental results in terms of realistic parameters and predicts a strong dependence of the non-local signal on the orbital depairing effect from an induced magnetic field.