Propagation of valley coherent self-resonant exciton-polaritons

Room temperature stable excitons near the K-point in few layer transition metal dichalcogenides (TMDs) such as WS2 dominate their optical response and offer a unique route for engineering light and matter interactions. To this end, we will discuss the observation of self-resonant exciton polaritons in 3L WS photonic crystals supporting a Fano type optical resonance. While the strong excitonic absorption allows for the experimental observation of exciton-polaritons, the valley coherent excitonic photoluminescence in few layer WS2 provides a unique mechanism for the investigation of valley coherent propagation of exciton polaritons.