Exciton-vibrational coupling in molecular aggregates: Electronic versus vibronic dimer
Exciton-vibrational coupling in molecular aggregates: Electronic versus vibronic dimer
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DOI：
10.1016/j.chemphys.2011.12.006
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发表时间：
2012-02-06
期刊：
影响因子：
2.3
通讯作者：
Pullerits, Tonu
中科院分区：
文献类型：
--
作者：
Polyutov, Sergey;Kuehn, Oliver;Pullerits, Tonu
对于两种不同的激子二聚体模型，研究了激子-振动耦合对能级结构、振子强度和驰豫动力学的影响。与纯电子二聚体相比，振动二聚体中的局域振动模导致了一个复杂的能级结构，包括避免交叉和激子态的性质从电子性质到振动性质的变化。除了这些静态性质外，我们还用Redfield松弛理论系统地研究了这两个模型的耗散动力学。在振动二聚体的情况下，这允许处理超出微扰理论和马尔可夫近似的限制的选定的振动自由度。结果表明，振动二聚体在单激子流形中产生了瞬时的振动布居陷阱。(C)2011爱思唯尔B.V.保留所有权利。
The influence of exciton-vibrational coupling on the energy level structure, oscillator strength, and relaxation dynamics is investigated for two different excitonic dimer models. As compared with a purely electronic dimer, the inclusion of local vibrational modes within a vibronic dimer gives rise to a complex energy level structure including avoided crossings and changes of the nature of the exciton states from electronic to vibrational character. Besides these static properties, the dissipative dynamics of the two models is systematically investigated using Redfield relaxation theory. In case of the vibronic dimer this allows to treat selected vibrational degrees of freedom beyond the limits of perturbation theory and Markov approximation. It is demonstrated that the vibronic dimer gives rise to transient vibrational population trapping in the one-exciton manifold. (C) 2011 Elsevier B.V. All rights reserved.