Photoinduced quantum dynamics in molecules have hierarchical temporal structures with different energy scales that are associated with electron and nuclear motions. Femtosecond-to-attosecond transient absorption spectroscopy (TAS) using high-harmonic generation (HHG) with a photon energy below 300 eV has been a powerful tool to observe such electron and nuclear dynamics in a table-top manner. However, comprehensive measurements of the electronic, vibrational, and rotational molecular dynamics have not yet been achieved. Here we demonstrate HHG-based TAS at the nitrogen $K$-edge (400 eV) for the first time to our knowledge and observe all the electronic, vibrational, and rotational degrees of freedom in a nitric oxide molecule at attosecond to sub-picosecond time scales. This method of employing core-to-valence transitions offers an all-optical approach to reveal the complete molecular dynamics in photochemical reactions with element and electronic state specificity.

中文翻译：

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使用400 eV的阿秒软X射线脉冲实时观察一氧化氮中的电子，振动和旋转动力学

分子中的光诱导量子动力学具有与电子和核运动相关的具有不同能级的分级时间结构。使用光子能量低于300 eV的高谐波产生（HHG）的飞秒到原子秒瞬态吸收光谱（TAS）一直是一种强大的工具，可以以台式方式观察这种电子和核动力学。但是，尚未实现对电子，振动和旋转分子动力学的全面测量。在这里，我们以氮气$ K $展示了基于HHG的TAS-首次（400 eV）到我们所知，并在一秒到亚皮秒的时间尺度上观察一氧化氮分子的所有电子，振动和旋转自由度。这种利用核价转变的方法提供了一种全光学方法，以揭示具有元素和电子态特异性的光化学反应中的完整分子动力学。