Meera Parish1
Monash University1
A strong coupling between light and matter is routinely achieved by embedding layers of semiconductor in an optical cavity. This results in the formation of exciton-polaritons, which are hybrid part-light, part-matter particles that are capable of realizing a range of quantum coherent phenomena. In this talk, I will discuss recent theoretical progress in understanding the interactions between exciton-polaritons and the role of optically dark states. When the exciton binding energy is sufficiently large, as is the case in transition metal dichalcogenides, I will show that it is possible to obtain exact analytical expressions for the spin-triplet and spin-singlet interaction strengths, which go beyond the Born approximation employed in previous calculations. Crucially, we find that the strong light-matter coupling enhances the strength of polariton-polariton interactions compared to that of the exciton-exciton interactions, due to the Rabi splitting and the small photon-exciton mass ratio.