Trapped fermion mixtures with unequal masses: a Bogoliubov-de Gennes approach
Menderes Iskin, Carl J. Williams
We use the Bogoliubov-de Gennes formalism to analyze the ground state phases of harmonically trapped two-species fermion mixtures with unequal masses. In the weakly attracting limit and around unitarity we find that the superfluid order parameter modulates spatially around the trap center, and that it's global maximum occurs at a finite distance away from the trap center where the mixture is locally unpolarized. As the attraction strength increases towards the molecular limit, the spatial modulations gradually disappear while the Bardeen-Cooper-Schrieffer (BCS) type nonmodulating superfluid region expands until the entire mixture becomes locally unpolarized.