Wang Yuanheng, Benny Alfy, Le Dé Brieuc, Chin Alex W, Scholes Gregory D
Department of Chemistry, Princeton University, Princeton, NJ 08544.
Sorbonne Université, CNRS, Institut des NanoSciences de Paris, Paris 75005, France.
Proc Natl Acad Sci U S A. 2025 Mar 4;122(9):e2416542122. doi: 10.1073/pnas.2416542122. Epub 2025 Feb 28.
Broadband pump-probe spectroscopy has been widely used to measure vibrational decoherence associated with the reaction coordinate in photoinduced ultrafast vibration-coupled electron transfer (VCET) reactions. These experiments provide insight into the interplay of intramolecular coordinates along the reaction coordinate. However, a general theoretical foundation for analyzing, and even for explaining rigorously, these data is lacking. In this work, we study vibrational decoherence in a model VCET reaction using the nearly exact time-dependent density matrix renormalization group simulation method. We explore how analyzing the density matrix with quantum information measures can help elucidate the evolution of vibrational coherence in simulations of dynamics. We examine how vibrational coherence is affected by electron transfer on the timescale of approximately 100 femtoseconds. Our results suggest that electron transfer, in the nonadiabatic model, changes the vibrational equilibrium position abruptly-an example of a "quantum quench" event. This explains the concomitant vibrational decoherence. We find that abrupt vibrational decoherence can be mitigated by wavepacket motion occurring on the timescale of the electron transfer.
宽带泵浦 - 探测光谱已被广泛用于测量与光诱导超快振动耦合电子转移（VCET）反应中反应坐标相关的振动退相干。这些实验为沿反应坐标的分子内坐标之间的相互作用提供了深入了解。然而，缺乏用于分析甚至严格解释这些数据的一般理论基础。在这项工作中，我们使用近乎精确的含时密度矩阵重整化群模拟方法研究模型VCET反应中的振动退相干。我们探索如何用量子信息度量分析密度矩阵有助于阐明动力学模拟中振动相干的演化。我们研究在大约100飞秒的时间尺度上电子转移如何影响振动相干。我们的结果表明，在非绝热模型中，电子转移会突然改变振动平衡位置——这是一个“量子猝灭”事件的例子。这解释了随之而来的振动退相干。我们发现，电子转移时间尺度上发生的波包运动可以减轻突然的振动退相干。
