Appropriate conditions to realize a p -wave superfluid state starting from a spin-orbit-coupled s -wave superfluid Fermi gas

We theoretically investigate a spin-orbit-coupled s-wave superfluid Fermi gas, to examine the time evolution of the system, after an s-wave pairing interaction is replaced by a p-wave one at t=0. In our recent paper [T. Yamaguchi, D. Inotani, and Y. Ohashi, J. Phys. Soc. Jpn. 86, 013001 (2017)JUPSAU0031-901510.7566/JPSJ.86.013001], we proposed that this manipulation may realize a p-wave superfluid Fermi gas because the p-wave pair amplitude that is induced in the s-wave superfluid state by a parity-broken antisymmetric spin-orbit interaction gives a nonvanishing p-wave superfluid order parameter, immediately after the p-wave interaction is turned on. In this paper, using a time-dependent Bogoliubov-de Gennes theory, we assess this idea under various conditions with respect to the s-wave and p-wave interaction strengths, as well as the spin-orbit coupling strength. From these, we clarify that the momentum distribution of Fermi atoms in the initial s-wave state (t<0) is a key to produce a large p-wave superfluid order parameter. Since the realization of a p-wave superfluid state is one of the most exciting and difficult challenges in cold Fermi gas physics, our results may provide a possible way to accomplish this.