Spin-Hall effects in a Josephson contact

TL;DR

This paper investigates spin-Hall effects in a Josephson contact with a 2D normal metal featuring spin-orbit coupling, revealing spin accumulation patterns but no spin-Hall current in the stationary state.

Contribution

It introduces a theoretical analysis of spin-Hall effects in Josephson junctions using Usadel equations, highlighting the similarity to spin diffusion and predicting specific spin polarization behaviors.

Findings

Out-of-plane spin-Hall polarization accumulates at sample edges

In-plane spin polarization exists throughout the normal region

No spin-Hall current in stationary Josephson effect

Abstract

The Josephson tunneling through a 2D normal contact with the spin-orbit split conduction band has been studied in the diffusive regime. Linearized Usadel equations for triplet components of the pairing function revealed a striking similarity to the equations of spin diffusion driven by the electric field in normal metals. Consequently, we predict that the out-of-plane spin-Hall polarization accumulates towards lateral sample edges and the in-plane polarization is finite throughout the entire normal region. At the same time, the spin-Hall current is absent in the considered case of the stationary Josephson effect.