Nonstandard pairing in asymmetric trapped Fermi gases

Abstract

We study an ultracold trapped Fermi gas of atoms in two hyperfine states with unequal populations. In this situation the usual BCS pairing is suppressed and nonstandard pairing mechanisms become important. These are treated by solving the Bogoliubov--de Gennes equations, which at the same time correctly take into account the finite size of the trapped system. We find results which can be viewed as generalization of the LOFF (Larkin-Ovchinnikov-Fulde-Ferrel) phase to finite systems.