COHERENT BACTERIAL FLUORESCENCE DYNAMICS - A SEMICLASSICAL MODEL

Oscillatory fluorescence in reaction centres of photosynthetic origin was assigned to coherent vibrational motion on the excited state poten tial surface by Vos and collaborators. We formalize this motion with a semiclassical wave packet consisting of several (intraprotein) modes. Our model indicates a dissipative (or collisional) to dephasing decay time ratio of 1/6 or less, and reproduces observed spectral features. We argue that the multi-mode semiclassical wave packet is more resist ant to quantal interference than a single-mode one.