Quantum Energy Transport in Photosynthesis -- Influence of strongly correlated and non-thermal environmental fluctuations

by Dr Peter Nalbach (U. Hamburg)

Thursday 22 May 2014, 16:30 → 17:30 Europe/Berlin

Sem. Raum 2 (DESY Hamburg)

Energy transport is the key process in many technological devices and natural systems. In photosynthesis, plants and bacteria transport energy after photoexcitation by the sun to a reaction center where the excitation energy is used to induce charge separation and chemical reactions. It is a long standing question if this later energy transfer is purely an incoherent hopping mechanism or if quantum coherence is present and potentially relevant. I address this question within a system-bath treatment where our focus is on the excitonic energy transfer which is disturbed by all other degrees of freedom. Importantly, in photosynthesis, environmental fluctuations are strongly temporarily and spatially correlated. I show that these prolong coherent effects. Furthermore, intra-molecular vibrations cannot thermalize on the sub-picosecond energy transfer times and thus provide non-thermal environmental fluctuations. These also prolong coherent effects and, at the same time, speed up energy transfer.