title: Modeling of ultrafast time-resolved fluorescence applied to a weakly coupled chromophore pair.
abstract: We present theory for calculating the third-order non-linear response function of a molecular aggregate in the weak inter-chromophore coupling regime. This approach is based on the perturbative expansion of the system evolution with respect to the resonance coupling, while the system-bath interaction is treated non-perturbatively by means of cumulant expansion. An explicit expression for the time-resolved fluorescence signal is then obtained. This allows us to investigate the ultrafast time-dependent Stokes shift, signatures of coherent dynamics, and the excitonic polaron formation in the excited state of the aggregate. Numerical simulations of the time-resolved fluorescence spectra of a pair of coupled molecules demonstrate these effects.
authors: Department of Theoretical Physics, Faculty of Physics, Vilnius University, Sauletekio Ave. 9, Building 3, LT-10222 Vilnius, Lithuania.
authors: V
authors: V
authors: Balevičius
authors: Department of Theoretical Physics, Faculty of Physics, Vilnius University, Sauletekio Ave. 9, Building 3, LT-10222 Vilnius, Lithuania.
authors: L
authors: L
authors: Valkunas
authors: Department of Theoretical Physics, Faculty of Physics, Vilnius University, Sauletekio Ave. 9, Building 3, LT-10222 Vilnius, Lithuania.
authors: D
authors: D
authors: Abramavicius