2D SNS junction with Rashba spin-orbit interaction

TL;DR

This paper investigates how Rashba spin-orbit interaction affects supercurrent in S-2DEG-S junctions, predicting spin-orbit induced splitting of Andreev states but finding the average Josephson current unaffected without electron-electron interactions.

Contribution

It generalizes Beenakker's formula to include spin-orbit scattering and analyzes the impact on Andreev levels and supercurrent in 2DEG-based junctions.

Findings

Rashba interaction causes splitting of Andreev bound states.

Semiclassical average Josephson current remains insensitive to Rashba coupling.

Spin-orbit effects are significant with non-zero interface backscattering.

Abstract

The effect of Rashba spin-orbital interaction upon supercurrent in S-2DEG-S proximity junctions is investigated in the clean limit. Generalization of Beenakker's formula for Andreev levels to the case of spin-orbital scattering is presented. Spin-orbit - induced splitting of Andreev bound-states is predicted for a junction of infinite width, and with non-vanishing normal backscattering at S/N interfaces. Semiclassical average of the Josephson current is however insensitive to the Rashba coupling as long as electron-electron interaction in 2DEG is neglected.