Resonantly enhanced polariton-mediated superconductivity in a doped transition metal dichalcogenide monolayer

Abstract: We present a proposal for achieving light-induced superconductivity using exciton polaritons - hybrid light-matter particles of excitons (bound electron-hole pairs) and microcavity photons. In contrast to previous theories of polariton-mediated superconductivity, which typically require multiple semiconductor layers, we show that superconductivity can be induced within a single semiconductor monolayer with inverted conduction bands, such as in the tungsten-based transition metal dichalcogenides. The key ingredient is that we can resonantly excite exciton polaritons into bands that are different from those occupied by the doped electrons, thus avoiding any Pauli blocking effects. Crucially, we can exploit the trion fine structure (i.e., multiple exciton-electron bound states) and tune the electron-polariton interactions via Feshbach resonances. Our theory of polariton-mediated superconductivity includes the energy dependence of the polariton-mediated interactions between electrons, as well as the polariton-induced changes to the electron quasiparticles. We find that superconductivity at elevated temperatures is within reach of current experiments.