Laser-Induced nonadiabatic processes in molecular systems: Theory and applications

本项目是我们在激光诱导非绝热过程领域的研究工作的继续。电子势能面之间的圆锥相交在非绝热分子过程中起着重要的作用。在CI情况下，电子态通过核运动耦合，并且电子与核之间的能量交换变得重要。对于多原子分子，CI无处不在。由于众所周知的“非交叉规则”，CI不能在无场的矩阵中形成。然而，通过应用外部字段，即使在图形中也可以创建CI。在这种情况下，激光诱导CI，CI将电子态与内部旋转和振动运动耦合。在我们以前的工作中已经指出，这种光诱导圆锥相交（LICI）对双原子分子的各种动力学性质（如分子光谱、分子排列或光解离几率）有很强的影响。我们的研究计划包括以下三个主要课题：（一）利用啁啾激光脉冲控制分子动力学过程。我们计划设计啁啾，以实现D2+的光解离过程的期望结果。(II)激光诱导圆锥相交对分子吸收光谱影响的演示。我们计划研究如何通常的弗兰克-康登近似打破了LICI的存在。(III)研究三原子系统中LICI的影响。特别地，我们计划研究臭氧分子的基态（X）和Hartley（B）态之间形成的LICI的影响。

In this project we continue our former research work on the field of laser-induced nonadiabatic processes. It is well known that conical intersections (CIs) between electronic potential energy surfaces play an important role in nonadiabatic molecular processes. In CI situations the electronic states are coupled by the nuclear motion and the energy exchange between the electrons and the nuclei becomes significant. For polyatomic molecules, CIs are ubiquitous. As a consequence of the well-known "noncrossing rule", CIs cannot be formed in field-free diatomics. However, by applying external fields, CI can be created even in diatomics. In this situation the laser light induces CIs which couple the electronic states and the internal rotation and vibrational motions. It was pointed out in our former works, that such light-induced conical intersections (LICIs) have very strong impact on various dynamical properties (like molecular spectra, molecular alignment or photodissociation probability) of diatomic molecules. Our research programme includes the following three major topics: (I) Controlling molecular dynamical processes by LICIs using chirped laser pulses. We plan to design the chirp such as to achieve a desired outcome of the photodissociation process of D2+. (II) Demonstration of the impact of the laser-induced conical intersections on the absorption spectra of molecules. We plan to investigate how the usual Franck-Condon approximation breaks down in the presence of LICIs. (III) Investigation of the impact of LICIs in triatomic systems. In particular, we plan to study the effect of the LICI formed between the ground (X) and the Hartley (B) states of the ozone molecule.