Critical temperature enhancement of topological superconductors: A dynamical mean-field study

Abstract

We show that a critical temperature Tc for spin-singlet two-dimensional superconductivity is enhanced by a cooperation between the Zeeman magnetic field and the Rashba spin-orbit coupling, where a superconductivity becomes topologically non-trivial below Tc. The dynamical mean field theory (DMFT) with the segment-based hybridization-expansion continuous-time quantum Monte Carlo impurity solver (ct-HYB) is used for accurately evaluating a critical temperature, without any Fermion sign problem. A strong-coupling approach shows that spin-flip driven local pair hopping leads to part of this enhancement, especially effects of the magnetic field. We propose physical settings suitable for verifying the present calculations, one-atom-layer system on Si(111) and ionic-liquid based electric double-layer transistors (EDLTs).