We show that a critical temperature $T_{\mathrm{c}}$ 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 nontrivial below $T_{\mathrm{c}}$. The dynamical mean-field theory with the segment-based hybridization-expansion continuous-time quantum Monte Carlo impurity solver 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, a one-atom-layer system on Si(111) and ionic-liquid-based electric double-layer transistors.

• Received 22 February 2016

DOI:https://doi.org/10.1103/PhysRevB.93.220505