Sato Yoshihiro, Doolittle Brian
Department of Physics and Astronomy, Colby College, Waterville, Maine 04901, USA.
J Chem Phys. 2014 Nov 14;141(18):185102. doi: 10.1063/1.4901056.
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.
我们通过数值研究了欠阻尼色素内振动模式对激子量子相干性和能量转移效率的影响。我们的模型描述了在光合能量转移发生的条件下的细菌叶绿素a色素 - 蛋白质二聚体。该二聚体使用电子 - 振动激子的理论处理进行建模，并使用非马尔可夫和非微扰方法对其动力学进行数值分析。我们研究了系统对黄 - 里斯因子、位点能量差、重组能和重组能差的各种值的响应。我们发现，包含色素内电子 - 振动模式会使长寿命的振荡量子相干得以出现。这种激子相干对静态位点能量无序具有鲁棒性。振动模式还促进激子沿位点能量态势的转移，从而提高整体能量转移效率。
