Fermion-Mediated Interactions Between Bosons in a Quantum Degenerate $^{133}$Cs-$^6$Li Bose-Fermi Mixture

We observe fermion-mediated interactions between bosonic atoms of $^{133}$Cs embedded in a degenerate Fermi gas (DFG) of $^6$Li atoms. The mediated interaction is the spinless analog of the RKKY (Ruderman-Kittel-Kasuya-Yosida) mechanism. Deep in quantum degeneracy, the strong mass imbalance and the different quantum statistics between two species lead to the Bose-Einstein Condensate (BEC) that is fully immersed in the DFG. From in situ imaging of the mixture, we observe an effective attraction between bosons and the formation of Bose-Fermi solitions, in full consistency with the predictions. In addition, we perform a measurement of the BEC's dipole oscillation near an interspecies Feshbach resonance. The interspecies interactions modify trapping frequency and damping rate of the BEC in the presence of the DFG.