Influence of intra-pigment vibrations on dynamics of photosynthetic exciton.
We have numerically investigated the effect of an underdamped intra-pigment vibrational mode on an exciton's quantum coherence and energy transfer efficiency. Our model describes a bacteriochlorophyll a pigment-protein dimer under the conditions at which photosynthetic energy transfer occurs. The dimer is modeled using a theoretical treatment of a vibronic exciton, and its dynamics are numerically analyzed using a non-Markovian and non-perturbative method. We examined the system's response to various values of the Huang-Rhys factor, site energy difference, reorganization energy, and reorganization energy difference. We found that the inclusion of the intra-pigment vibronic mode allows for long-lived oscillatory quantum coherences to occur. This excitonic coherence is robust against static site-energy disorder. The vibrational mode also promotes exciton transfer along the site-energy landscape thus improving the overall energy transfer efficiency.
Department of Physics and Astronomy, Colby College, Waterville, Maine 04901, USA.
Yoshihiro
Y
Sato
Department of Physics and Astronomy, Colby College, Waterville, Maine 04901, USA.
Brian
B
Doolittle
D025541:Bacteriochlorophyll A / Q000737:chemistry*; D019281:Dimerization; D004735:Energy Transfer; D008954:Models, Biological; D014732:Vibration
D025541:Bacteriochlorophyll A