Breached pair superfluidity for cold fermionic atoms

The study of cold atomic gases is exploding, driven largely by the rapid experimental developments. This field has become highly interdisciplinary, connecting a great variety of interesting problems: weakly and strongly correlated quantum condensed matter, nuclear matter, etc. In this talk, I will focus on one of the hottest topics in the field---fermionic superfluidity. After describing the current developments in this area, I would venture into a new direction called "breached pairing". This ground state of fermions contains both a superfluid and a normal Fermi liquid while preserving translational and rotational invariances. It requires the idea of phase-separation in momentum space, with gapless Fermi surfaces acting as domain boundaries. I will discuss when the state becomes stable and suggest ways of possible experimental realization. A general story may be found from Phys. Rev. Focus at http://focus.aps.org/story/v15/st1.