Invitation to a talk: K. Birgitta Whaley, Wednesday Feb. 21th 2018, 11:00 AM at the IQOQI Seminar Room

Understanding the quantum efficiency of light harvesting photosynthetic systems one photon at a time

Photosynthetic light harvesting of plants and bacteria in vivo is characterized by the remarkable capability of producing electron-hole pairs from absorbed photons with near unit quantum efficiency under weak illumination conditions.  Ultrafast spectroscopic studies have revealed much insight into the microscopic dynamics of excitonic energy transport that follows the initial process of photoexcitation, but the microscopic spatio-temporal dynamics of photon absorption is still poorly understood.  I shall review the current state of understanding of quantum dynamics of energy transfer in light harvesting complexes, and then present an integrated fully quantum theoretical description of the combined processes of single photon absorption and subsequent excitonic energy transfer.  This will be followed by discussion of opportunities for using heralded single photon sources to probe the microscopic mechanism of transduction of photon energy to electron-hole pair formation in photosynthesis.