Preparational effects on the excitation energy transfer in the FMO complex

Using numerically exact path integral Monte Carlo simulations, the excitation energy transfer in the Fenna-Matthews-Olson (FMO) complex is determined at room temperature. The employed system and environment parameters are based on previously reported atomistic simulations. When starting with excitations localized at specific chromophores, no coherence features can be observed. In contrast, when starting with delocalized excitations, traces of coherent motion become apparent. On the one hand, as experimental findings account for much stronger quantum coherent motion, these results suggest a reevaluation of the underlying spectral densities. On the other hand, the results emphasize that the initial preparation of the excitonic system needs to be taken into account carefully when attempting to reproduce the respective experiments.