Fermion-mediated pairing and long range interactions in a Cs-Li Bose-Fermi mixture

The Efimov effect, originally proposed in a nuclear physics context, predicts a universal series of three-body bound states near a two-body resonance. The RKKY interaction, originally proposed in a condensed matter context, describes a long-range interaction between impurities immersed in a degenerate Fermi gas. Recent experiments employing various techniques have established both of these effects in ultracold Bose-Fermi mixtures. In this work, we investigate these fermion-mediated interactions in a strongly interacting ¹³³Cs-⁶Li mixture. We show that at sufficiently strong boson-fermion attraction, the fermion-mediated interaction can induce a binding resonance in the bosonic component. These results represent a novel connection between the many-body RKKY interaction and few-body bound-state physics in ultracold atomic mixtures.