Sheng Zirui, Jiang Tong, Li Weitang, Shuai Zhigang
School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, P. R. China.
MOE Key Laboratory of Organic OptoElectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, 100084 Beijing, P. R. China.
J Chem Theory Comput. 2024 Aug 13;20(15):6470-6484. doi: 10.1021/acs.jctc.4c00493. Epub 2024 Aug 1.
Photosynthesis is a fundamental process that converts solar energy into chemical energy. Understanding the microscopic mechanisms of energy transfer in photosynthetic systems is crucial for the development of novel optoelectronic materials. Simulating these processes poses significant challenges due to the intricate interactions between electrons and phonons, compounded by static disorder. In this work, we present a numerically nearly exact study using the time-dependent density matrix renormalization group (TD-DMRG) method to simulate the quantum dynamics of the Fenna-Matthews-Olson (FMO) complex considering an eight-site model with both thermal and static disorders. We employ the thermo-field dynamics formalism for temperature effects. We merge all electronic interactions into one large matrix product state (MPS) site, boosting accuracy efficiently without increasing complexity. Previous combined experimental and computational studies indicated that the static disorders range from 30 to 90 cm for different FMO sites. We employ a Gaussian distribution and the auxiliary bosonic operator approach to consider the static disorder in our TD-DMRG algorithm. We investigate the impact of different initial excitation sites, temperatures, and degrees of static disorder on the exciton dynamics and temporal coherence. It is found that under the influence of the experimentally determined static disorder strength, the exciton population evolution shows a non-negligible difference at zero temperature, while it is hardly affected at room temperature.
光合作用是一个将太阳能转化为化学能的基本过程。理解光合系统中能量转移的微观机制对于新型光电子材料的开发至关重要。由于电子与声子之间复杂的相互作用，再加上静态无序，模拟这些过程面临着重大挑战。在这项工作中，我们使用含时密度矩阵重整化群（TD-DMRG）方法进行了一项数值上近乎精确的研究，以模拟费纳-马修斯-奥尔森（FMO）复合物的量子动力学，该研究考虑了一个具有热无序和静态无序的八位点模型。我们采用热场动力学形式来处理温度效应。我们将所有电子相互作用合并到一个大的矩阵乘积态（MPS）位点中，在不增加复杂性的情况下有效地提高了精度。先前的实验和计算相结合的研究表明，不同FMO位点的静态无序范围为30至90厘米。我们在TD-DMRG算法中采用高斯分布和辅助玻色子算符方法来考虑静态无序。我们研究了不同初始激发位点、温度和静态无序程度对激子动力学和时间相干性的影响。研究发现，在实验确定的静态无序强度影响下，激子布居演化在零温度下显示出不可忽略的差异，而在室温下几乎不受影响。
