Topological px + ipy superfluid phase of fermionic polar molecules

We discuss the topological p(x) + ip(y) superfluid phase in a two-dimensional (2D) gas of single-component fermionic polar molecules dressed by a circularly polarized microwave field. This phase emerges because the molecules may interact with each other via a potential V-0(r) that has an attractive dipole-dipole 1/r(3) tail, which provides p-wave superfluid pairing at fairly high temperatures. We calculate the amplitude of elastic p-wave scattering in the potential V-0(r) taking into account both the anomalous scattering due to the dipole-dipole tail and the short-range contribution. This amplitude is then used for the analytical and numerical solution of the renormalized BCS gap equation which includes the second-order Gor'kov-Melik-Barkhudarov corrections and the correction related to the effective mass of the quasiparticles. We find that the critical temperature T-c can be varied within a few orders of magnitude by modifying the short-range part of the potential V-0(r). The decay of the system via collisional relaxation of molecules to dressed states with lower energies is rather slow due to the necessity of a large momentum transfer. The presence of a constant transverse electric field reduces the inelastic rate, and the lifetime of the system can be of the order of seconds even at 2D densities similar to 10(9) cm(-2). This leads to T-c of up to a few tens of nanokelvins and makes it realistic to obtain the topological p(x) + ip(y) phase in experiments with ultracold polar molecules.