Conical intersections (CIs) have been widely studied using spectroscopic techniques. However, CIs have mainly been identified by rapid internal conversion transitions that take place after the photoexcitation. Such identifications cannot distinguish various types of intersections as well as to separate the actual intersection from an avoided crossing. In this paper, we investigate how ultrafast IR laser pulses can be utilized to stimulate nuclear dynamics revealing geometric phase features associated with CIs. We consider two low-dimensional nonadiabatic models to obtain optimal two- and three-pulse laser sequences for stimulating nuclear dynamics necessary for the CI identification. Our results provide insights on designing non-linear spectroscopic schemes for subsequent probes of the nuclear wavepackets by ultrafast electron diffraction techniques to unambiguously detect CIs in molecules.

圆锥形交叉点（CIs）已使用光谱技术进行了广泛研究。但是，CIs主要是通过光激发后发生的快速内部转化来确定的。这样的标识不能区分各种类型的交叉点，也不能将实际的交叉点与避免的交叉点分开。在本文中，我们研究了如何利用超快的红外激光脉冲来激发揭示几何相位的核动力学。与CI相关的功能。我们考虑了两个低维非绝热模型，以获得最佳的两脉冲和三脉冲激光序列，以刺激CI识别所需的核动力学。我们的研究结果为通过超快电子衍射技术为核波包的后续探针设计非线性光谱方案提供了真知灼见，以明确检测分子中的CI。