Conical intersections induced by classical and quantum light

自由的多原子分子在其势能面之间表现出大量的圆锥形相交（CIs）。在电子激发（或电离）之后，这些CIs对随后的核动力学产生重大影响，导致强烈的非绝热效应。经典光（激光）和量子光（腔）也可以诱导CIs，甚至在双原子分子中也是如此。这两种光诱导CIs （LICIs）对多原子分子的影响研究很少。这个项目解决了两个主要问题。a)离子态共振耦合的量子场存在时的电离。所选择的分子（丁巳烯）已知具有强烈影响游离分子电离谱的天然CI。研究自然CI和人工智能之间的相互作用是这个子项目的中心。为了进行比较，本文还将计算和研究激光场诱导的LICI的光谱。b)用经典场激发分子后探测腔内的非绝热动力学。在核动力学过程中，所形成的极化子态为光子-电子杂化态，且空腔可以辐射。重点是研究动力学，并探讨非绝热动力学与可测辐射之间是否存在关系。我们将研究两种情况，一种是（甲醛），其中不涉及天然CI，另一种是（吡嗪），其中存在天然CI，我们可以研究与LICI的相互作用。由于该项目研究的是新的基本效应，所要研究的系统必须足够复杂，以验证现象，并充分了解，以便进行未来预测所需的准确计算。

Free polyatomic molecules abundantly exhibit conical intersections (CIs) between their potential energy surfaces. Following electronic excitation (or ionization), these CIs have a substantial impact on the ensuing nuclear dynamics leading to strong non-adiabatic effects. CIs can also be induced by classical (laser) and quantum (cavity) light and this even in diatomic molecules. The impact of these two kinds of light-induced CIs (LICIs) has only very little been explored for polyatomic molecules. This project addresses two main issues. a) Ionization in the presence of a quantum field which couples resonantly ionic states. The molecule chosen (butatriene) is known to have a natural CI which strongly affects the ionization spectrum of the free molecule. The investigation of the interplay between the natural CI and the LICI stands in the center of this subproject. For comparison, the spectrum with a LICI induced by a laser field will also be computed and studied. b) Probing non-adiabatic dynamics in a cavity after exciting the molecule by a classical field. The polaritonic states formed are hybrid photonic-electronic states and the cavity can radiate during the nuclear dynamics. The main point is to study the dynamics and, in addition, explore whether there is a relationship between the non-adiabatic dynamics and the radiation which is measureable. Two cases will be studied, one (formaldehyde) where there is no natural CI involved, and one (pyrazine) where a natural CI is present and we can investigate the interplay with the LICI. Since the project is on new fundamental effects, the systems to be studied were chosen such that they are sufficiently complex to validate the phenomena and sufficiently known to allow for accurate calculations needed for future predictions.