Accurate Simulation of Spectroscopic Signatures of Cavity-Assisted, Conical-Intersection-Controlled Singlet Fission Processes

A numerically accurate, fully quantum methodology has been developed for the simulation of the dynamics and nonlinear spectroscopic signals of cavity-assisted, conical-intersection-controlled singlet fission systems. The methodology is capable of handling several molecular systems strongly coupled to the photonic mode of the cavity and treats the intrinsic conical intersection and cavity-induced polaritonic conical intersections in a numerically exact manner. Contributions of higher-lying molecular electronic states are accounted for comprehensively. The intriguing process of cavity-modified fission dynamics, including all of its electronic, vibrational, and photonic degrees of freedom, together with its two-dimensional spectroscopic manifestation, is simulated for two rubrene dimers strongly coupled to the cavity mode. Ministry of Education (MOE) Submitted/Accepted version The authors gratefully acknowledge the support of the Singapore Ministry of Education Academic Research Fund (Grants RG190/18 and RG87/20). K.S. thanks the Natural Science Foundation of Zhejiang Province (Grant LY18A040005) for partial support. M.F.G. acknowledges the support of Hangzhou Dianzi University through startup funding.