Feshbach resonances and polaron physics in bilayer semiconductors

Bilayer structures of two dimensional materials have been proven to be invaluable platforms to study correlated quantum matter. Semiconductors such as transition metal dichalcogenides (TMDs) are particularly interesting, as they host strongly interacting electrons as well as tightly bound composite bosons in the form of excitons. In this talk we show how scattering between excitons and electrons can be enhanced in bilayer TMDs, by using a solid-state analogue of a Feshbach resonance. Similar to its counterpart in ultracold atomic systems, this resonance allows for precise control of interactions, which facilitates the realization of strongly coupled Bose-Fermi mixtures. As a first step we analyze the properties of a Fermi polaron which forms when a single exciton is resonantly coupled to a Fermi sea of electrons. Experimental signatures and opportunities for the generation of degenerate Bose-Fermi mixtures are also discussed.