标题： 非微扰激子转移速率分析在减少和氧化条件下的芬纳-马修斯-奥尔森光合复合体 显示英文标题

标题： Non-perturbative exciton transfer rate analysis of the Fenna-Matthews-Olson photosynthetic complex under reduced and oxidised conditions

摘要： 二维光学光谱实验表明，在芬纳-马修斯-奥尔森(FMO)光合复合物中，激发子传递路径在还原和氧化条件下存在显著差异，这表明集体振动子机制可能在还原形式中起功能作用，但在氧化状态下被减弱。 Higgins等。 [PNAS 118 (11) e2018240118 (2021)] 使用Redfield理论将实验观察结果与由于氧化局域能量位移导致的激发子传递速率变化联系起来，这些位移使激发子能量间隙偏离细菌叶绿素(BChl) a的特定振动频率。 通过使用层次运动方程的记忆核公式，我们提出了非微扰的传递速率估计，这些估计产生了一个修改后的物理图像。 我们的研究结果表明，仅靠局域能量位移无法在定性或定量上再现氧化环境中的观测到的速率变化。 通过系统地检查氧化复合物中局域能量和局部环境的综合变化，同时保持与吸收光谱的一致性，我们的结果表明，传递速率的振动子调谐可能确实在还原复合物中起作用。 然而，我们与实验测量的速率只有定性的相符，而非定量的相符。 我们的分析表明，FMO电子哈密顿量可能存在局限性，该哈密顿量最初是通过将光谱拟合到二阶累积和Redfield理论而得出的。 这表明，有必要用非微扰方案重新评估这些电子参数，或者从第一性原理推导出这些参数，这对于在不同氧化还原条件下一致且准确地理解FMO中的激发子动力学至关重要。 显示英文摘要

摘要： Two-dimensional optical spectroscopy experiments have shown that exciton transfer pathways in the Fenna-Matthews-Olson (FMO) photosynthetic complex differ drastically under reduced and oxidised conditions, suggesting a functional role for collective vibronic mechanisms that may be active in the reduced form but attenuated in the oxidised state. Higgins et al. [PNAS 118 (11) e2018240118 (2021)] used Redfield theory to link the experimental observations to altered exciton transfer rates due to oxidative onsite energy shifts that detune excitonic energy gaps from a specific vibrational frequency of the bacteriochlorophyll (BChl) a. Using a memory kernel formulation of the hierarchical equations of motion, we present non-perturbative estimations of transfer rates that yield a modified physical picture. Our findings indicate that onsite energy shifts alone cannot reproduce the observed rate changes in oxidative environments, either qualitatively or quantitatively. By systematically examining combined changes both in site energies and the local environment for the oxidised complex, while maintaining consistency with absorption spectra, our results suggest that vibronic tuning of transfer rates may indeed be active in the reduced complex. However, we achieve qualitative, but not quantitative, agreement with the experimentally measured rates. Our analysis indicates potential limitations of the FMO electronic Hamiltonian, which was originally derived by fitting spectra to second-order cumulant and Redfield theories. This suggests that reassessment of these electronic parameters with a non-perturbative scheme, or derived from first principles, is essential for a consistent and accurate understanding of exciton dynamics in FMO under varying redox conditions.