Electronic coherences in molecules are ultrafast charge oscillations on the molecular frame (MF) and their direct observation and separation from electronic population dynamics is challenging. Here we present a valence shell lab frame (LF) scattering method suited to probing electronic coherences in isolated systems. MF electronic coherences lead to LF electronic anisotropies observable by ultrafast angle-resolved scattering. Moment analysis of the LF anisotropy completely separates electronic coherences from population dynamics, demonstrated in excited state NH 3 using ultrafast time-energy-angle-resolved photoelectron spectroscopy. This general approach applies equally to attosecond/femtosecond electronic coherences in isolated systems.

中文翻译：

---

来自实验室框架散射各向异性的超快分子框架电子相干性

分子中的电子相干是分子框架（MF）上的超快速电荷振荡，直接观察和将其与电子种群动力学分离是很有挑战性的。在这里，我们提出一种价壳实验室框架（LF）散射方法，适用于探测孤立系统中的电子相干性。MF电子相干导致LF电子各向异性，可通过超快角度分辨散射观察到。LF各向异性的矩分析将电子相干与种群动力学完全分开，这在NH 3激发态下使用超快时间-能量角分辨光电子能谱进行了证明。这种通用方法同样适用于隔离系统中的阿秒/飞秒电子相干性。