Pairing in Feshbach-resonant trapped fermionic atom gases with unequal species populations

Interest in BCS-like pairing with unequal Fermi surfaces has recently been revived due to the possibility of its realization in ultracold atomic gases, and the first experimental measurements have appeared in the past few months. We briefly review zero-momentum pairing with unequal chemical potentials for the two species. We then describe effects of an external trapping potential on the pairing process, and the resulting shell structure of different phases in the trap.