Energy Fluctuations Induced Quantum Decoherence and Exciton Localization in Singlet Fission
journal contributionposted on 02.12.2019, 15:45 by Guohua Tao
Both quantum coherent and incoherent mechanisms have been revealed in singlet exciton fission. Also, in some systems, both mechanisms may concurrently operate. However, the comprehensive picture is not fully understood yet. Here, we proposed a theoretical model for quantum transition (QT) from the coherent to incoherent regime in singlet fission (SF) featuring a characteristic factor of the ratio between the fluctuation of the electron–phonon coupling energy and the effective interstate couplings, in connection with the theory of Anderson localization. The model is demonstrated to be able to interpret the nonadiabatic molecular dynamics simulation of SF in quantitative details, providing an intuitive mechanical picture on how the QT takes place and how the coherent and incoherent components of the fission dynamic could coexist, which would be valuable for understanding fission mechanisms and developing new fission materials.