Topological superconductivity in the attractive Rashba-Hubbard model: A quantum Monte Carlo dynamical cluster approximation study

Fully gapped, spin singlet superconductors with antisymmetric spin-orbit coupling in a Zeeman magnetic field provide a promising route to realize superconducting states with non-Abelian topological order and therefore fault-tolerant quantum computation. Here we use a quantum Monte Carlo dynamical cluster approximation to study the superconducting properties of a doped two-dimensional attractive Hubbard model with Rashba spin orbit coupling in a Zeeman magnetic field. In the absence of spin orbit coupling, we find that the Zeeman field completely suppresses superconductivity in this model as expected from the Pauli depairing effect. When the Rashba spin orbit coupling is turned on, however, superconductivity is restored at finite temperatures. By inspecting the Fermi surface of the interacting model, we can draw conclusions about the topological character of the superconducting state.