An analytical continuation approach for evaluating emission lineshapes of molecular aggregates and the adequacy of multichromophoric Forster theory
An analytical continuation approach for evaluating emission lineshapes of molecular aggregates and the adequacy of multichromophoric Forster theory
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DOI：
10.1063/1.4803694
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发表时间：
2013-05-14
影响因子：
4.4
通讯作者：
Giorda, Paolo
中科院分区：
文献类型：
--
作者：
Banchi, Leonardo;Costagliola, Gianluca;Giorda, Paolo
在大的光合发色团-蛋白质复合物中，不是所有的发色团都是强偶联的，因此这种情况可以通过在强偶联的发色团的某些区域中形成离域状态来很好地描述。为了在不进行大量数值计算的情况下描述不同畴之间的激发能量转移，最流行的技术之一是Sumi [B，252（1999）]和Scholes和Fleming [B，1854（2000）]提出的将Forster理论推广到多生色团聚集体（广义Forster理论）。该文致力于研究两个问题.首先，利用解析延拓和无时间卷积的量子主方程方法，提出了一个多生色团体系或分子聚集体的发射谱线形状理论。第二，一个全面的框架，允许一个明确的，紧凑的，有效的研究多生色团的方法，在完整的一般版本提出的张，牛顿，和西尔贝[物理修订快报。92，218301（2004）]中所述的方法。我们将本理论应用于简单的聚合系统，一方面说明了无时间卷积技术在推导线型算符中的有效性，另一方面说明了多生色团方法如何在能量传递率的确定中给出显著的改进，特别是当所研究的系统不是纯粹的Forster系统时。所提出的方案允许有效地实现多生色团Forster方法，该方法可用于模拟大型光合聚集体中的能量传递动力学，对于大型光合聚集体，通常需要大量计算资源。此外，我们的方法允许系统地比较多生色团福斯特和广义福斯特理论，并清楚地了解各自的有效性限度。(C)2013 AIP出版有限责任公司。
In large photosynthetic chromophore-protein complexes not all chromophores are coupled strongly, and thus the situation is well described by formation of delocalized states in certain domains of strongly coupled chromophores. In order to describe excitation energy transfer among different domains without performing extensive numerical calculations, one of the most popular techniques is a generalization of Forster theory to multichromophoric aggregates (generalized Forster theory) proposed by Sumi [J. Phys. Chem. B 103, 252 (1999)] and Scholes and Fleming [J. Phys. Chem. B 104, 1854 (2000)]. The aim of this paper is twofold. In the first place, by means of analytic continuation and a time convolutionless quantum master equation approach, a theory of emission lineshape of multichromophoric systems or molecular aggregates is proposed. In the second place, a comprehensive framework that allows for a clear, compact, and effective study of the multichromophoric approach in the full general version proposed by Jang, Newton, and Silbey [Phys. Rev. Lett. 92, 218301 (2004)] is developed. We apply the present theory to simple paradigmatic systems and we show on one hand the effectiveness of time-convolutionless techniques in deriving lineshape operators and on the other hand we show how the multichromophoric approach can give significant improvements in the determination of energy transfer rates in particular when the systems under study are not the purely Forster regime. The presented scheme allows for an effective implementation of the multichromophoric Forster approach which may be of use for simulating energy transfer dynamics in large photosynthetic aggregates, for which massive computational resources are usually required. Furthermore, our method allows for a systematic comparison of multichromophoric Foster and generalized Forster theories and for a clear understanding of their respective limits of validity. (C) 2013 AIP Publishing LLC.