Non-Hermitian phenomena in dissipative coupled polaritons

Dissipative coupling refers to the effect where two systems interact with each other mediated by dissipation channels. Recent advances in controlling light-matter systems have opened new avenues to explore non-Hermitian effects arising from dissipative coupling, such as level attraction and anomalous dispersions. In this work, we perform a parametric study of these effects in a polariton system, i.e., a light-matter superposition, under both dissipative and coherent coupling. We characterize the effects of different sources of non-Hermitian behavior and analytically identify the conditions for the emergence of negative effective mass, exceptional points, and bound states in the continuum as a function of the light-matter detuning, the coherent-to-dissipative coupling ratio, and the relative decay rate of the non-interacting subsystems. We also analyze the classical limit of the polariton system within a non-Hermitian framework, employing coherent states.