Fermi-Fermi Mixtures in the Strong Attraction Limit

Abstract

The phase diagrams of low density Fermi-Fermi mixtures with equal or unequal masses and equal or unequal populations are described at zero and finite temperatures in the strong attraction limit. In this limit, the Fermi-Fermi mixture can be described by a weakly interacting Bose-Fermi mixture, where the bosons correspond to Feshbach molecules and the fermions correspond to excess atoms. First, we discuss the three and four fermion scattering processes, and use the exact boson-fermion and boson-boson scattering lengths to generate the phase diagrams in terms of the underlying fermion-fermion scattering length. In three dimensions, in addition to the normal and uniform superfluid phases, we find two stable non-uniform states corresponding to (1) phase separation between pure unpaired (excess) and pure paired fermions (molecular bosons); and (2) phase separation between pure excess fermions and a mixture of excess fermions and molecular bosons. Lastly, we also discuss the effects of the trapping potential in the density profiles of condensed and non-condensed molecular bosons, and excess fermions at zero and finite temperatures, and discuss possible implications of our findings to experiments involving mixtures of ultracold fermions.

12 Pages, 6 Figures and 1 Table

References in corpus (7)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Molecular Probe of Pairing in the BEC-BCS Crossover
• Diatomic molecules in ultracold Fermi gases - Novel composite bosons
• Mean field thermodynamics of a spin-polarized spherically trapped Fermi gas at unitarity
• Imbalanced Fermi superfluid in a one-dimensional optical potential
• Spin-polarized Fermi superfluids as Bose-Fermi mixtures

Cited by in corpus (7)

• Theory of ultracold Fermi gases
• Realization of a strongly interacting Bose-Fermi mixture from a two-component Fermi gas
• Superfluidity at the BEC-BCS crossover in two-dimensional Fermi gases with population and mass imbalance
• Small mass- and trap-imbalanced two-component Fermi systems
• Quantum phases of Fermi-Fermi mixtures in optical lattices
• Density profiles of polarized Fermi gases confined in harmonic traps
• Vortex core states in superfluid Fermi-Fermi mixtures with unequal masses