Proton Coupled Coherent Charge Transfer
Photosynthetic reaction centers perform light induced charge separation over a membrane with a high quantum yield of 95%. Since the structure of the membrane complex of the bacterial reaction center of Rps. viridis has been resolved, by Michel, Deisenhofer and Huber (Nobel prize 1985), it became a great challenge to resolve the observed dynamics on the basis of the structure information. The ongoing research in the field is motivated by the hope to learn from nature, how to improve the efficiency of artificial solar cells. We start with the so called step model, where the transfer to the primary stable acceptor proceeds via an intermediate in terms of two nonadiabatic electron transfer rate processes. In the second part we provide information on the involvement of reversible proton shifts, which modulates the electronic coupling via adiabatic delocalization of hole states. Finally we simulate coherence effects, which support the more complex model of coherently modulated superexchange.