arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.07180physics.chem-phcond-mat.mes-hall
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弱光驱动下分子聚集体中激子动力学的精确描述

Exact description of excitonic dynamics in molecular aggregates weakly driven by light

Veljko Janković, Tomáš Mančal

摘要:

我们提出了一个严格的理论描述的激子动力学的分子捕光聚集体光激发的弱强度辐射的任意属性。虽然与光的相互作用包括到第二阶,治疗的激发-环境耦合是准确的,并导致在一个精确的表达式为减少激子密度矩阵,这是明显相关的光谱图片的光激发过程。该表达式充分考虑了由与光的两种相互作用触发的环境重组过程。这对于缓慢环境和/或强激发-环境耦合特别重要。在指数分解方案中,我们展示了我们的结果如何可以被改写为运动方程(HEOM)的层次结构,明确和一贯地包括光激发步骤。我们分析描述的环境重组动力学触发的一个三角洲样激发的一个单一的发色团,并演示了我们的HEOM,在适当的限制,减少到Redfield方程,包括脉冲光激发和非平衡Foerster理论。我们还讨论了我们的形式主义相结合的Born-Markov-HEOM方法的热光激发的情况下的关系。

英文摘要:

We present a rigorous theoretical description of excitonic dynamics in molecular light-harvesting aggregates photoexcited by weak-intensity radiation of arbitrary properties. While the interaction with light is included up to the second order, the treatment of the excitation-environment coupling is exact and results in an exact expression for the reduced excitonic density matrix that is manifestly related to the spectroscopic picture of the photoexcitation process. This expression takes fully into account the environmental reorganization processes triggered by the two interactions with light. This is particularly important for slow environments and/or strong excitation-environment coupling. Within the exponential decomposition scheme, we demonstrate how our result can be recast as the hierarchy of equations of motion (HEOM) that explicitly and consistently includes the photoexcitation step. We analytically describe the environmental reorganization dynamics triggered by a delta-like excitation of a single chromophore, and demonstrate how our HEOM, in appropriate limits, reduces to the Redfield equations comprising a pulsed photoexcitation and the nonequilibrium Foerster theory. We also discuss the relation of our formalism to the combined Born-Markov-HEOM approaches in the case of excitation by thermal light.

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