Gu Bing, Franco Ignacio
Department of Chemistry, University of Rochester , Rochester, New York 14627, United States.
Department of Physics, University of Rochester , Rochester, New York 14627, United States.
J Phys Chem Lett. 2018 Feb 15;9(4):773-778. doi: 10.1021/acs.jpclett.7b03322. Epub 2018 Feb 2.
We introduce a general theory of electronic decoherence for molecules in the condensed phase that captures contributions coming from pure dephasing effects, electronic transitions among diabatic states, and their interference. The theory is constructed by taking advantage of a recently developed [ J. Phys. Chem. Lett. 2017 , 8 , 4289 - 4294 ] general expression for decoherence times that is based on an early time expansion of the purity dynamics and extends early electronic decoherence models based on pure dephasing ideas. Using this theory, we construct the decoherence time for the displaced harmonic oscillator model amended with constant and linear diabatic couplings, which is a widely used model of the photoexcited dynamics of molecules. The validity of the short-time expansion is demonstrated by the quantitative agreement of the theory with exact numerical computations of the decoherence dynamics obtained using the hierarchical equation of motion method. These developments offer a rigorous understanding of early time electronic decoherence processes that accompany basic molecular events and demonstrate that electronic transitions among diabatic states play a major role in the decoherence dynamics.
我们介绍了一种适用于凝聚相中分子的电子退相干的通用理论，该理论涵盖了来自纯退相效应、绝热态之间的电子跃迁及其干涉的贡献。该理论是利用最近开发的[《物理化学快报》2017年，8卷，4289 - 4294页]退相干时间的通用表达式构建的，该表达式基于纯度动力学的早期时间展开，并扩展了基于纯退相思想的早期电子退相干模型。利用该理论，我们构建了用常数和线性绝热耦合修正的位移谐振子模型的退相干时间，这是一种广泛使用的分子光激发动力学模型。通过该理论与使用运动方程分层方法获得的退相干动力学的精确数值计算的定量一致性，证明了短时展开的有效性。这些进展为伴随基本分子事件的早期电子退相干过程提供了严格的理解，并表明绝热态之间的电子跃迁在退相干动力学中起主要作用。
