Superconducting Pairing Symmetry on the Extended Hubbard Model in the Presence of the Rashba-Type Spin–Orbit Coupling

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.