Title: Coherence and its Role in Excitation Energy Transfer in Fenna-Mathews-Olson Complex,
Abstract: We show that the coherence between different bacteriochlorophyll-a (BChla)
sites in the Fenna-Mathews-Olson complex is an essential ingredient for
excitation energy transfer between various sites. The coherence delocalizes the
excitation energy, which results in the redistribution of excitation among all
the BChla sites in the steady state. We further show that the system remains
partially coherent at the steady state. In our numerical simulation of the
non-Markovian density matrix equation, we consider both the inhomogeneity of
the protein environment and the effect of active vibronic modes.