Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
J Chem Phys. 2018 Mar 28;148(12):124114. doi: 10.1063/1.5028121.
We present a theoretical study of the quantum dynamics of energy transfer in a model photosynthetic dimer excited by incoherent light and show that the interplay between incoherent pumping and phonon-induced relaxation, dephasing, and trapping leads to the emergence of non-equilibrium stationary states characterized by substantial stationary coherences in the energy basis. We obtain analytic expressions for these coherences in the limits of rapid dephasing of electronic excitations and of small excitonic coupling between the chromophores. The stationary coherences are maximized in the regime where the excitonic coupling is small compared to the trapping rate. We further show that the non-equilibrium coherences anti-correlate with the energy transfer efficiency in the regime of localized coupling to the reaction center and that no correlation exists under delocalized (Förster) trapping conditions.
我们提出了一个模型光合作用二聚体的量子动力学理论研究，该模型由非相干光激发，并表明非相干泵浦与声子诱导的弛豫、退相和俘获之间的相互作用导致了非平衡定态的出现，这些定态在能量基中表现出显著的定态相干性。我们在电子激发快速退相和发色团之间的激子耦合较小的极限下，获得了这些相干性的解析表达式。在与俘获速率相比，激子耦合较小的情况下，定态相干性最大。我们进一步表明，在与反应中心局部耦合的情况下，非平衡相干性与能量转移效率呈反相关，而在非局域（Förster）俘获条件下则不存在相关性。
