BCS–BEC crossover of spin imbalanced Fermi gases with Rashba spin–orbit coupling

• The BCS–CBEC crossover of 3D spin polarized Fermi gases with Rashba SOC was studied based on pair fluctuation theory.
• We then present the detailed results of various TcTc curves which can also be thought as preliminary phase diagrams.
• Our result shows that the effects of spin polarization and SOC largely canceled out.
• The stable region of spin polarized superfluid state is greatly enlarged by introducing the SOC term.

We study the BCS–Bose Einstein Condensation (BEC) crossover of a three-dimensional spin polarized Fermi gas with Rashba spin–orbital coupling (SOC). At finite temperature, the effects of non-condensed pairs due to the thermal excitation are considered based on the G0GG0G pair fluctuation theory. These fluctuations generate a pseudogap even persistent above TcTc. Within this framework, the Sarma state or the spin polarized superfluid state and polarized pseudogap state are explored in detail. The resulting TcTc curves show that the enhancement of pairing due to the SOC roughly cancels out the suppression of pairing due to the population imbalance. Thus we observed that in a large portion of the parameter space, the polarized superfluid state are stabilized by the SOC.