Theoretical Study of Li-Cs Degenerate Trapped Fermi-Bose Mixtures

Recent experiments by deSalvo et al [ArXiv 1706.01220] have observed a
Bose-Fermi mixture involving a stable Cs Bose-Einstein condensate (BEC) and
a Li-degenerate Fermi gas. There is a high interest in such mixtures as
possible prototypes for addressing high-temperature superconductors. Making
this Li-Cs atomic gas a rather ideal system, all inter- and intra-species
interactions are associated with well-characterized and widely tunable
Feshbach resonances. In this talk, we use a mean-field theory of a trapped
gas mixture, involving the appropriately narrow (closed channel,
attractive) Li-Cs resonance to address the observation of self-trapping of
several hundred fermions inside the Bose condensate. For this finite-size
system, we show the extent to which the interaction with the BEC (beyond
trapping) leads to deviations from ideal Fermi gas properties.