汇报标题(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——启发阿秒化学之路）
汇报人(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），法国国度科学钻研中心，光与物质钻研所）
汇报功夫(Time)：2026年6月3日（星期三）15:00
汇报地址(Place): Zoom在线会议室：
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
主办部门：理学院物理系
提要(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，使得人们可能观测和操控产生在原子与分子电荷活动内禀功夫尺度内的动力学过程。这为阿秒化学妄想的实现打开了大门，即通过对系统引发后最初瞬间产生的纯电子动力学——电荷迁徙——的操控来节造化学反映。
因而，分子系统中长命命电子有关性的存在，是实现该指标的第一个关键前提。此表，理解导致有关性失落或阻止其失落的机造，对于阿秒化学的发展亦是必要的。
本文将介绍阿秒电荷迁徙中退有关与复原的初次丈量。该动力学过程产生在硅烷(SiH?)被红表脉冲引发之后。文中将会商对电子和核自由度均作量子力学处置的模拟，正是这些模拟使得尝试了局得以被诠释。利用这些模拟，能够对有关性的行为以及有关性通过圆锥交叉得以维持的可能性作出合理诠释。
实现阿秒化学的第二个关键前提是理解电荷迁徙若何影响分子系统的反映活性。最近，在腺嘌呤上进行的极紫表泵浦–红表探测尝试在其双阳离子信号中观测到了低于3飞秒的延长。利用多电子波包传布推算，将展示该延长源于分子关联能带区域中产生的关联驱动电荷迁徙，这一过程使系统趋于不变。该不变动源于所产生空穴的离域化，以及其特点从σ向π的转变。所观测到的动力学拥有普适性，这使得关联能带成为索求阿秒化学所提供可能性的辽阔平台。
