Inverse Spin Hall Effect in SNS Josephson Junctions

TL;DR

This paper investigates how spin-orbit coupling and Zeeman fields in SNS Josephson junctions induce an equilibrium supercurrent analogous to the inverse spin Hall effect, with explicit calculations for Rashba coupling in disordered 2D electron gases.

Contribution

It introduces a novel mechanism linking spin-orbit effects and Zeeman fields to equilibrium supercurrents in SNS junctions, expanding understanding of spin-charge conversion phenomena.

Findings

Equilibrium supercurrent can be induced by spin-orbit and Zeeman effects.

The effect is explicitly computed for Rashba coupling in disordered 2D systems.

The phenomenon resembles the inverse spin Hall effect in normal conductors.

Abstract

We consider DC supercurrents in SNS junctions. Spin-orbit coupling in combination with Zeeman fields can induce an effective vector potential in the normal conductor. As a consequence, an out-of-plane spin-density varying along the transverse direction causes a longitudinal phase difference between the superconducting terminals. The resulting equilibrium phase coherent supercurrent is analogue to the non-equilibrium inverse spin Hall effect in normal conductors. We explicitly compute the effect for the Rashba spin orbit coupling in a disordered two-dimensional electron gas with an inhomogeneous perpendicular Zeeman field.