Nature of superfluidity in ultracold Fermi gases near Feshbach resonances

Abstract

We study the superfluid state of atomic Fermi gases using a BCS-Bose-Einstein-condensation crossover theory. Our approach emphasizes noncondensed fermion pairs which strongly hybridize with their (Feshbach-induced) molecular boson counterparts. These pairs lead to pseudogap effects above ${T}_{c}$ and non-BCS characteristics below. We discuss how these effects influence the experimental signatures of superfluidity.