Temperature-dependent quantum beats between neutral and charged excitons in monolayer MoSe2

Abstract

We studied the interaction between the neutral and charged excitons of monolayer MoSe2 at various temperatures via quantum beat spectroscopy in the time domain. We introduced temperature as an efficient control knob to regulate the relative photoluminescence intensities of the neutral and charged excitons to obtain maximum quantum beat resolution. Furthermore, our quantum beat measurements under different temperatures indicate that the decoherence time of the coupled exciton-trion state slightly decreases from 530 fs at 3.5 K to 420 fs at 63 K with increased temperature due to the low-energy acoustic phonon-induced dephasing.