On the adequacy of the Redfield equation and related approaches to the study of quantum dynamics in electronic energy transfer
On the adequacy of the Redfield equation and related approaches to the study of quantum dynamics in electronic energy transfer
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DOI：
10.1063/1.3155214
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发表时间：
2009-06-21
影响因子：
4.4
通讯作者：
Fleming, Graham R.
中科院分区：
文献类型：
--
作者：
Ishizaki, Akihito;Fleming, Graham R.
Engel [Nature（伦敦）446，782（2007）]对光合激发能量转移（EET）中的长寿命电子相干性的观察提出了关于蛋白质环境在保护这种相干性中的作用以及量子相干性在光捕获效率中的重要性的问题。在本文中，我们探讨了Redfield方程的适用性，在其完整的形式，在长期的近似和忽略的虚部的弛豫项的研究这些现象。我们发现，没有一种方法可以给出一个可靠的图片的光合EET环境中的作用。特别是流行的长期近似（或相应的Lindblad方程）在非相干传输区产生异常行为，导致高估的环境辅助传输的贡献。另一方面，完整的雷德菲尔德表达式在大型重组能源区域中产生了与环境无关的动态。一篇配套论文提出了一种改进的方法，纠正了这些缺陷[A. Ishizaki和G. R. Fleming，J.Chem.Phys.130，234111（2009）]。
The observation of long-lived electronic coherence in photosynthetic excitation energy transfer (EET) by Engel [Nature (London) 446, 782 (2007)] raises questions about the role of the protein environment in protecting this coherence and the significance of the quantum coherence in light harvesting efficiency. In this paper we explore the applicability of the Redfield equation in its full form, in the secular approximation and with neglect of the imaginary part of the relaxation terms for the study of these phenomena. We find that none of the methods can give a reliable picture of the role of the environment in photosynthetic EET. In particular the popular secular approximation (or the corresponding Lindblad equation) produces anomalous behavior in the incoherent transfer region leading to overestimation of the contribution of environment-assisted transfer. The full Redfield expression on the other hand produces environment-independent dynamics in the large reorganization energy region. A companion paper presents an improved approach, which corrects these deficiencies [A. Ishizaki and G. R. Fleming, J. Chem. Phys. 130, 234111 (2009)].