Cooper Pairing in A Doped 2D Antiferromagnet with Spin-Orbit Coupling

TL;DR

This paper investigates how spin-orbit coupling influences antiferromagnetic order and Cooper pairing in a doped 2D Hubbard model, revealing a shift from s+d-wave to s+p-wave pairing with increasing spin-orbit interaction.

Contribution

It provides a detailed analysis of the effects of Rashba spin-orbit coupling on magnetic and pairing properties in a doped 2D Hubbard model, highlighting a transition in pairing symmetry.

Findings

Spin-orbit coupling suppresses antiferromagnetic order.

Magnetic susceptibility becomes anisotropic with spin-orbit coupling.

Spin-orbit coupling favors s+p-wave pairing over s+d-wave pairing.

Abstract

We study the two-dimensional Hubbard model with the Rashba type spin-orbit coupling within and beyond the mean-field theory. The antiferromagnetic ground state for the model at half-filling and the Cooper pairing induced by antiferromagnetic spin fluctuations near half-filling are examined based on the random-phase approximation. We show that the antiferromagnetic order is suppressed and the magnetic susceptibility turns out to be anisotropic in the presence of the spin-orbit coupling. Energy spectrums of transverse spin fluctuations are obtained and the effective interactions between holes mediated by antiferromagnetic spin fluctuations are deduced in the case of low hole doping. It seems that the spin-orbit coupling tends to form s+p-wave Cooper pairs, while the s+d-wave pairing is dominant when the spin-orbit coupling is absent.