Fulde-Ferrell-Larkin-Ovchinnikov state of two-dimensional imbalanced Fermi gases

الأصل · EN

The ground-state phase diagram of attractively-interacting Fermi gases in two dimensions with a population imbalance is investigated. We find the regime of stability for the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase, in which pairing occurs at finite wave vector, and determine the magnitude of the pairing amplitude Δ and FFLO wavevector q in the ordered phase, finding that Δ can be of the order of the two-body binding energy. Our results rely on a careful analysis of the zero temperature gap equation for the FFLO state, which possesses nonanalyticities as a function of Δ and q, invalidating a Ginzburg-Landau expansion in small Δ.