Exciton Dynamics and Time-Resolved Fluorescence in Nanocavity-Integrated Monolayers of Transition-Metal Dichalcogenides

We have developed an ab initio-based, fully quantum, numerically accurate methodology for the simulation of the exciton dynamics and time- and frequency-resolved fluorescence spectra of the cavity-controlled two-dimensional materials at finite temperatures and applied this methodology to the single-layer WSe2 system. Specifically, the multiple Davydov D2 Ansatz has been employed in combination with the method of thermofield dynamics for the finite-temperature extension of accurate time-dependent variation. This allowed us to establish dynamical and spectroscopic signatures of the polaronic and polaritonic effects as well as uncover their characteristic time scales in the relevant range of temperatures. Our study reveals the pivotal role of multidimensional conical intersections in controlling the many-body dynamics of highly intertwined excitonic, phononic, and photonic modes. Ministry of Education (MOE) Submitted/Accepted version The authors gratefully acknowledge the support of the Singapore Ministry of Education Academic Research Fund (Grant Nos. RG190/18 and RG87/20). K. Sun would also like to thank the Natural Science Foundation of Zhejiang Province (Grant No. LY18A040005) for partial Support. M. F. G. acknowledges the support of Hangzhou Dianzi University through startup funding.