title: Underdamped vibrations control the primary electron transfer in photosynthesis at low temperatures.
abstract: Measurements performed with the help of ultrafast laser spectroscopy have clearly shown that the primary electron transfer in photosynthesis lasts no longer than a few picoseconds. Equally fast are processes of vibrational relaxation which have to be taken into account in the correct description of the phenomenon. Here, we consider a simple theory combining the electron transfer process with diffusion in the energy space of a chosen underdamped vibrational mode of protein environment. Analytical formulas for effective transition rate constants are derived, and a transient kinetics is considered. The quality of analytical approximations is verified by numerical simulations for various physical conditions. Efficient parallel computations have been applied. The model can explain a peculiar temperature dependence of pump-probe spectra observed.
authors.affiliation: Faculty of Physics, Adam Mickiewicz University, Poznań, Poland.
authors.forename: Mieczyslaw
authors.initials: M
authors.lastname: Torchala
authors.forename: Michal
authors.initials: M
authors.lastname: Kurzynski