j9九游会

报告问题(Title)：Ab-initio simulations of ultrafast electron-nuclear dynamics:Paving the way to attochemistry（重新算模拟超快电子-核动力学——开发阿秒化学之路）

报告人(Speaker)：Victor Despré（Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière，，，，里昂第一大学（克洛德·贝尔纳大学），，，，法国国家科学研究中心，，，，光与物质研究所）

报告时间(Time)：2026年6月3日（星期三）15:00

报告所在(Place): Zoom在线聚会室：

https://us06web.zoom.us/j/85258759346?pwd=YYNArN7GfS5ynVsClgo4SvCwSdetEx.1

Meeting Chat Link

https://us06web.zoom.us/launch/jc/85258759346

Conference ID: 852 5875 9346

Password: 153372

约请人(Inviter)：李永乐教授

主理部分：理学院物理系

摘要(Abstract)：

The advent of attosecond physics allowed the observation and manipulation of dynamic processes occurring within the intrinsic time scale of the charge motion in atoms and molecules. This has opened the door to the realization of the dream of attochemistry, namely to control chemical reactions through the manipulation of the pure electron dynamics, the charge migration [1], taking place in the first instants after the excitation of the system.

Thereby, the existence of long-lasting electronic coherences in molecular systems is the first key prerequisite to its realization. Furthermore, understating the mechanism leading to or preventing the loss of coherence is necessary for its development.

The first measurement of decoherence and revival in attosecond charge migration will be presented [2]. This dynamics occurs after excitation of silane (SiH4) by an IR pulse. Simulations treating quantum mechanically both the electronic and nuclear degrees of freedom permitting the interpretation of the experimental results will be discussed. Using these simulations, the behavior of the coherence and the possibility to conserve coherence trough conical intersection will be rationalized.

The second key prerequisite of the realization of attochemistry is the understanding of how charge migration can impact the reactivity of a molecular system. Recently, an XUV-pump IR-probe experiment performed on adenine has demonstrated a sub 3 fs delay in its dicationic signal. It will be shown, using multielectron wave-packet propagation, that this delay is due to a correlation-driven charge migration occurring in the correlation band [3] region of the molecule that stabilizes the system. The stabilization is due to the delocalization of the created hole and its change from σ to π character. The generality of the observed dynamics makes correlation bands a promising playground for the exploration of the possibilities offered by attochemistry.

References

[1] Guiot du Doignon, C.; Sinha-Roy, R.; Rabilloud, F.; Despré, V.: Correlation-Driven Charge Migration Triggered by Infrared Multi-Photon Ionization, Chem. Sci. 16, 16729-16736, 2025.

[2] Matselyukh, D.; Despré, V.; Golubev, N. V.; Kuleff, A. I.; W?rner H. J.: Decoherence and revival in attosecond charge migration driven by non-adiabatic dynamics, Nature Physics 18, 1206-1213, 2022.

[3] Hervé, M.; Despré, V.; Castellanos Nash, P.; Loriot, V.; Boyer, A.; Scognamiglio, A.; Karras, G.; Brédy, R.; Constant, E.; Tielens, A. G. G. M.; Kuleff, A. I.; Lépine, F.: Ultrafast dynamics of correlation bands following XUV molecular photoionization, Nature Physics 17, 327-331, 2021.

阿秒物理学的问世，，，，使得人们能够视察和操控爆发在原子与分子电荷运动内禀时间标准内的动力学历程。。。这为阿秒化学梦想的实现翻开了大门，，，，即通过对系统引发后最初瞬间爆发的纯电子动力学——电荷迁徙——的操控来控制化学反映。。。

因此，，，，分子系统中长寿命电子相关性的保存，，，，是实现该目的的第一个要害条件。。。别的，，，，明确导致相关性损失或阻止其损失的机制，，，，关于阿秒化学的生长亦是须要的。。。

本文将介绍阿秒电荷迁徙中退相关与恢复的首次丈量。。。该动力学历程爆发在硅烷(SiH?)被红外脉冲引发之后。。。文中将讨论对电子和核自由度均作量子力学处理的模拟，，，，正是这些模拟使得实验效果得以被诠释。。。使用这些模拟，，，，可以对相关性的行为以及相关性通过圆锥交织得以坚持的可能性作出合明确释。。。

实现阿秒化学的第二个要害条件是明确电荷迁徙怎样影响分子系统的反映活性。。。最近，，，，在腺嘌呤上举行的极紫外泵浦–红外探测实验在其双阳离子信号中视察到了低于3飞秒的延迟。。。使用多电子波包撒播盘算，，，，将展示该延迟源于分子关联能带区域中爆发的关联驱动电荷迁徙，，，，这一历程使系统趋于稳固。。。该稳固化源于所爆发空穴的离域化，，，，以及其特征从σ向π的转变。。。所视察到的动力学具有普适性，，，，这使得关联能带成为探索阿秒化学所提供可能性的辽阔平台。。。