  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).
