Effects of spin orbit coupling on proximity induced superconductivity

TL;DR

This paper explores how spin orbit coupling influences proximity-induced superconductivity in heterostructures, revealing the emergence of mixed pairing states and the impact of impurities, with implications for materials exhibiting spin-momentum locking.

Contribution

It introduces a theoretical analysis of how Rashba spin orbit coupling affects superconducting pairing in heterostructures, including the formation of odd-frequency triplet pairs.

Findings

Spin orbit coupling induces mixed singlet and triplet pairing.

Under certain conditions, odd-frequency triplet pairs can form.

Impurity scattering influences the stability of induced pairs.

Abstract

We investigate the effect of spin orbit coupling on proximity induced superconductivity in a normal metal attached to a superconductor. Specifically, we consider a heterostructure where the presence of interfaces gives rise to a Rashba spin orbit coupling. The properties of the induced superconductivity in these systems are addressed within the tunneling Hamiltonian formalism. We find that the spin orbit coupling induces a mixture of singlet and triplet pairing and, under specific circumstances, an odd frequency, even parity, spin triplet pairs can arise. We also address the effect of impurity scattering on the induced pairs, and discuss our results in context of heterostructures consisting of materials with spin-momentum locking.