Dani Reshmi, Kundu Sohang, Makri Nancy
Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States.
Department of Physics, University of Illinois, Urbana, Illinois 61801, United States.
J Phys Chem Lett. 2023 Apr 27;14(16):3835-3843. doi: 10.1021/acs.jpclett.3c00670. Epub 2023 Apr 17.
We present and analyze coherence maps [ 2022, 126, 9361-9375] to investigate the quantum coherences that are created, sustained, and damped by vibrational modes during the transfer of excitation energy from the B800 (outer) to the B850 (inner) ring of the light harvesting complex 2 (LH2) of purple bacteria with a variety of initial conditions. The reduced density matrix of the 24-pigment complex, where the ground and excited electronic states of each bacteriochlorophyll are explicitly coupled to 50 intramolecular vibrations at room temperature, is obtained from fully quantum-mechanical small matrix path integral (SMatPI) calculations. The coherence maps show a very rapid localization within the outer ring, accompanied by the formation of inter-ring quantum superpositions that evolve to a partial quantum delocalization at equilibrium, and quantify in state-to-state detail the flow of energy within the complex.
我们展示并分析了相干图谱[2022, 126, 9361 - 9375]，以研究在紫色细菌光捕获复合物2（LH2）中，从B800（外环）到B850（内环）的激发能量转移过程中，由振动模式产生、维持和衰减的量子相干性，该过程具有多种初始条件。通过全量子力学的小矩阵路径积分（SMatPI）计算，得到了24色素复合物的约化密度矩阵，其中每个细菌叶绿素的基态和激发态电子态在室温下与50个分子内振动明确耦合。相干图谱显示在外环内有非常快速的局域化，伴随着环间量子叠加的形成，这种叠加在平衡时演变为部分量子离域，并详细地逐态量化了复合物内的能量流动。
