Highly nonlinear trion-polaritons in a monolayer semiconductor

摘要

Optical microscope image of the MoSe flake, highlighted with a red border, encapsulated in hBN and clamped with two golden contacts on top of the bottom mirror. PL emission of the flake under off-resonant excitation with exciton (X) and trion (T) peaks highlighted. The observed order of magnitude difference for the intensity of the PL of the trion relative to the exciton arises from fast neutral exciton to trion states relaxation processes due to scattering with phonons and electrons. Scheme of experiment for resonant excitation of the open cavity in the transmission geometry. PL emission as a function of the detuning between bare cavity mode (C) and exciton (X) plotted in logarithmic colour scale; black points (dots) are experimental peak positions of the polariton resonances extracted from the fitting of experimental spectra at each detuning with a Gaussian; solid lines are theoretical polariton branches. Higher order transverse LG modes are also observed on the left and right-hand side of polariton states. Normalised PL spectra around trion resonance, showing anticrossing behaviour. Schematic showing emission and absorption of driven polariton resonance and interactions with the reservoir of trions and excitons.