Theory of magnetotrion-polaritons in transition metal dichalcogenide monolayers

Magnetic field is a powerful tool for the manipulation of material's electronic and optical properties. In the domain of transition metal dichalcogenide monolayers, it allows one to unveil the spin, valley, and orbital properties of many-body excitonic complexes. Here we study theoretically the impact of normal-to-plane magnetic field on trions and trion-polaritons. We demonstrate that spin and orbital effects of a magnetic field give comparable contributions to the trion energies. Moreover, as magnetic field redistributes the free electron gas between two valleys in the conductance band, the trion-photon coupling becomes polarization and valley dependent. This results in an effective giant Zeeman splitting of trion-polaritons, in-line with the recent experimental observations.