Dowek Danielle, Decleva Piero
Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.
CNR IOM and Dipartimento DSCF, Università di Trieste, Trieste, Italy.
Phys Chem Chem Phys. 2022 Oct 19;24(40):24614-24654. doi: 10.1039/d2cp02725a.
The field of angle-resolved molecular photoelectron spectroscopy is reviewed, with emphasis on foundations and most recent applications in different regimes of light-matter interaction. The basic formalism underlying one-photon electron angular distributions is presented, from the primary molecular frame (MF) photoemission emission from fully oriented molecules to laboratory frame (LF) observables produced from randomly oriented targets, extensions to multiphoton and strong field processes being briefly described, followed by a survey of current quantum mechanical computational approaches. The description of experimental developments is focused on the advancements in two major instrumentation fields for angle-resolved PES of molecules in the last two decades, namely charged-particle imaging spectrometers and adiabatically or impulsively laser-induced molecular alignment, together with their interplay with the remarkable characteristics achieved nowadays by the ionizing light sources and the challenging control of complex molecules in the gas phase. Aspects and applications of LF angular observables from unoriented targets are presented, with contemporary applications, especially as probes of the target electronic structure, including higher angular observables, in particular photoelectron circular dichroism (PECD) from chiral molecules, which is confirmed as a powerful chiral technique, and higher terms arising from multiphoton or non-dipole terms. Molecular frame photoelectron angular distributions (MFPADs), which stand out as the most complete observables of molecular photoionization stereodynamics in different excitation regimes, now broadly extended to characterize molecular structure and dynamics, are then discussed stemming from fully oriented molecules tackled by electron-ion momentum coincidence techniques, or from laser aligned samples. Finally, novel developments and challenging perspectives, notably the implementation of PAD in time-resolved schemes at ultrashort time scales, high energy, and high intensity regimes are drawn.
本文综述了角分辨分子光电子能谱领域，重点介绍了光与物质相互作用不同 regime 下的基础及最新应用。介绍了单光子电子角分布的基本形式，从完全取向分子的初级分子框架（MF）光发射到随机取向靶产生的实验室框架（LF）可观测量，简要描述了向多光子和强场过程的扩展，随后概述了当前的量子力学计算方法。实验进展的描述重点关注过去二十年中用于分子角分辨光电子能谱的两个主要仪器领域的进展，即带电粒子成像光谱仪和绝热或脉冲激光诱导的分子取向，以及它们与当今电离光源所实现的显著特性以及气相中复杂分子的具有挑战性的控制之间的相互作用。介绍了来自未取向靶的 LF 角可观测量的方面和应用，包括当代应用，特别是作为靶电子结构的探针，包括更高阶角可观测量，特别是手性分子的光电子圆二色性（PECD），它被确认为一种强大的手性技术，以及多光子或非偶极项产生的更高阶项。分子框架光电子角分布（MFPADs）作为不同激发 regime 下分子光电离立体动力学最完整的可观测量脱颖而出，现在广泛扩展用于表征分子结构和动力学，然后讨论了源于通过电子 - 离子动量符合技术处理的完全取向分子或激光取向样品的 MFPADs。最后，阐述了新的发展和具有挑战性的前景，特别是在超短时间尺度、高能量和高强度 regime 的时间分辨方案中 PAD 的实施。
