Electron

Attosecond

Atomic physics

Optics

Femtosecond

Spectroscopy

Molecular physics

Quantum mechanics

Photon

Ultrashort pulse

Photon energy

Electronic structure

Ultrafast laser spectroscopy

Femtochemistry

Picosecond

Computational chemistry

Chemistry

Physics

Laser

Optica

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, 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 complete molecular dynamics in photochemical reactions with element and electronic state specificity.

Real-time observation of electronic, vibrational, and rotational dynamics in nitric oxide with attosecond soft x-ray pulses at 400 eV