Superconducting pairing symmetry on the extended Hubbard model in the presence of the Rashba-type spin-orbit coupling

TL;DR

This study investigates how Rashba spin-orbit coupling influences pairing symmetries in a two-dimensional extended Hubbard model, revealing mixed singlet-triplet pairings and their dependence on interaction parameters and electronic dispersion.

Contribution

It provides a detailed analysis of the pairing symmetry phase diagram in the presence of Rashba spin-orbit coupling using Eliashberg's equation within the RPA framework.

Findings

Three pairing symmetries appear with mixed singlet-triplet character.

Admixture depends on dominant pairing symmetry, dispersion, and interaction.

Phase diagram varies with Coulomb interactions U and V.

Abstract

In order to study the pairing symmetry in non-centrosymmetric superconductors, we solve the linearized Eliashberg's equation on the two-dimensional extended Hubbard model in the presence of the Rashba-type spin-orbit coupling (RSOC) within the random phase approximation. In the presence of the RSOC, three types of pairing symmetries appear in the phase diagram with respect to the on-site Coulomb repulsion U and off-site one V. Each of pairing symmetries is admixture of spin-singlet and -triplet ones. On the basis of analytical study, it is found that the admixture of spin-singlet and -triplet components depends on not only the predominant pairing symmetry but also dispersion relation and pairing interaction.