标题： 手性莰烯光电子圆二色性的中间态依赖性通过飞秒共振增强多光子电离观察到 显示英文标题

标题： Intermediate state dependence of the photoelectron circular dichroism of fenchone observed via femtosecond resonance-enhanced multi-photon ionization

摘要： 共振增强多光子电离过程中，樟脑在气相中光电子圆二色性（PECD）的中间态依赖性被实验研究。 通过从359到431纳米扫描激发波长，我们同时激发最多三个电子上不同的共振。 在使用宽带飞秒激光器进行的PECD实验中，可以分辨出它们对光电子谱的各自贡献。 高分辨率光谱使我们能够将其中两个共振识别为属于B带和C带，它们分别涉及激发到具有3s和3p里德伯特征的状态。 我们观察到PECD信号的符号变化，这取决于使用哪个电子态作为中间态。 此外，扫描激光波长显示，对于3s态，PECD幅度随着光电子能量的增加而减少。 显示英文摘要

摘要： The intermediate state dependence of photoelectron circular dichroism (PECD) in resonance-enhanced multi-photon ionization of fenchone in the gas phase is experimentally studied. By scanning the excitation wavelength from 359 to 431 nm we simultaneously excite up to three electronically distinct resonances. In the PECD experiment performed with a broadband femtosecond laser their respective contributions to the photoelectron spectrum can be resolved. High-resolution spectroscopy allows us to identify two of the resonances as belonging to the B- and C-bands, which involve excitation to states with 3s and 3p Rydberg character, respectively. We observe a sign change in the PECD signal depending on which electronic state is used as an intermediate. Additionally, scanning the laser wavelength reveals a decrease of PECD magnitude with increasing photoelectron energy for the 3s state.