Effects of spin-orbit coupling and spatial symmetries on the Josephson current in SNS junctions

TL;DR

This paper investigates how spin-orbit interactions, magnetic fields, and structural asymmetries influence the interference patterns of critical currents in 2D SNS Josephson junctions, linking measurable patterns to underlying symmetries.

Contribution

It provides a symmetry-based analysis connecting interference patterns to Hamiltonian symmetries in SNS junctions with spin-orbit coupling and magnetic fields.

Findings

Symmetry relations predict interference pattern features.

Numerical calculations confirm the qualitative analysis.

Structural asymmetries affect the Josephson current behavior.

Abstract

We present an analysis of the symmetries of the interference pattern of critical currents through a two-dimensional superconductor-semiconductor-superconductor junction, taking into account Rashba and Dresselhaus spin-orbit interaction, an arbitrarily oriented magnetic field, disorder, and structural asymmetries. We relate the symmetries of the pattern to the absence or presence of symmetries in the Hamiltonian, which provides a qualitative connection between easily measurable quantities and the spin-orbit coupling and other symmetries of the junction. We support our analysis with numerical calculations of the Josephson current based on a perturbative expansion up to eighth order in tunnel coupling between the normal region and the superconductors.