School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
J Chem Phys. 2012 Sep 7;137(9):094107. doi: 10.1063/1.4748571.
We investigate the influence of static disorder and thermal excitations on excitonic energy transport in the light-harvesting apparatus of photosynthetic systems by solving the Schrödinger equation and taking into account the coherent hoppings of excitons, the rates of exciton creation and annihilation in antennas and reaction centers, and the coupling to thermally excited phonons. The antennas and reaction centers are modeled, respectively, as the sources and drains which provide the channels for creation and annihilation of excitons. Phonon modes below a maximum frequency are coupled to the excitons that are continuously created in the antennas and depleted in the reaction centers, and the phonon population in these modes obeys the Bose-Einstein distribution at a given temperature. It is found that the energy transport is not only robust against the static disorder and the thermal noise, but it can also be enhanced by increasing the randomness and temperature in most parameter regimes. Relevance of our work to the highly efficient energy transport in photosynthetic systems is discussed.
我们通过求解薛定谔方程并考虑激子的相干跳跃、天线和反应中心中激子的产生和湮灭速率以及与热激发声子的耦合，研究了静态无序和热激发对光合作用系统中光捕获装置中激子能量输运的影响。天线和反应中心分别被建模为提供激子产生和湮灭通道的源和漏。低于最大频率的声子模式与连续在天线中产生并在反应中心中耗尽的激子耦合，并且这些模式中的声子种群在给定温度下服从玻色-爱因斯坦分布。结果表明，能量输运不仅对静态无序和热噪声具有鲁棒性，而且在大多数参数区域中，通过增加随机性和温度，还可以增强能量输运。讨论了我们的工作与光合作用系统中高效能量输运的相关性。
