Pairing symmetry in an anisotropic Fermi superfluid under a p-wave Feshbach resonance

The anisotropic Fermi superfluid of ultra-cold Fermi atoms under the p-wave Feshbach resonance is studied theoretically. The pairing symmetry of the ground state is determined by the strength of the atom-atom magnetic dipole interaction. It is k(z) for a strong dipole interaction; while it becomes k(z)-i beta k(y), up to a rotation about z, for a weak one. (Here beta < 1 is a numerical coefficient.) By changing the external magnetic field or the atomic gas density, a phase transition between these two states can be driven. We discuss how the pairing symmetry of the ground state can be determined in the time-of-flight experiments.