Spin-Hall current and spin polarization in an electrically biased SNS Josephson junction

TL;DR

This paper investigates how a dc electric bias induces a periodic spin-Hall current and spin polarization in a superconductor-normal-superconductor Josephson junction with Rashba spin-orbit coupling, revealing non-zero spin currents unlike stationary cases.

Contribution

It introduces a theoretical analysis of time-periodic spin-Hall effects in SNS Josephson junctions considering Rashba spin-orbit coupling and proximity effects, highlighting non-zero spin currents.

Findings

Spin-Hall current remains non-zero in the dynamic regime.

Spin polarization is driven by periodic electric fields and proximity effects.

The study uses diffusion approximation and perturbation expansion.

Abstract

Periodic in time spin-Hall current and spin polarization induced by a dc electric bias has been calculated in a superconductor-normal 2DEG-superconductor (SNS) Josephson junction. We assumed that the band energies of electrons in the normal system are splitted due to Rashba spin-orbit coupling. The transport parameters have been calculated within the diffusion approximation and using perturbation expansion over a small SN contact transparency. We found out that in contrast to the stationary Josephson effect, the spin-Hall current does not turn to zero. Besides a direct proximity effect caused by Cooper pair's transition into a triplet state, the spin current and polarization are also driven by a periodic electric field associated with the charge imbalance.