Triplet p + ip pairing correlations in the doped Kane-Mele-Hubbard model: A quantum Monte Carlo study

¹ Department of Physics, Beijing Normal University - Beijing 100875, China
² Beijing Computational Science Research Center - Beijing 100094, China
³ Theoretical Division, Los Alamos National Laboratory - Los Alamos, NM 87545 USA

Received: 9 June 2015
Accepted: 3 August 2015

Abstract

By using the constrained-phase quantum Monte Carlo method, we performed a systematic study of the pairing correlations in the ground state of the doped Kane-Mele-Hubbard model on a honeycomb lattice. We find that pairing correlations with d + id symmetry dominate close to half-filling, but pairing correlations with p + ip symmetry dominate as hole doping moves the system below three-quarters filling. We correlate these behaviors of the pairing correlations with the topology of the Fermi surfaces of the non-interacting problem. We also find that the effective pairing correlation is enhanced greatly as the interaction increases, and these superconducting correlations are robust against varying the spin-orbit coupling strength. Our numerical results suggest a possible way to realize spin triplet superconductivity in doped honeycomb-like materials or ultracold atoms in optical traps.