Clocking Enhanced Ionization of Hydrogen Molecules with Rotational Wave Packets

作者：Yonghao Mi, Peng Peng, Nicolas Camus, Xufei Sun, Patrick Froß, Denhi Martínez, Z. Dube, P. B. Corkum, D. M. Villeneuve, A. Staudte, Robert Moshammer, Thomas Pfeifer · 发表于：Physical Review Letters · 年份：2020 · DOI：10.1103/physrevlett.125.173201 · 被引用次数：21 · 研究领域：Laser-Matter Interactions and Applications、Mass Spectrometry Techniques and Applications、Atomic and Molecular Physics

Laser-induced rotational wave packets of H_{2} and D_{2} molecules were experimentally measured in real time by using two sequential 25-fs laser pulses and a reaction microscope. By measuring the time-dependent yields of the above-threshold dissociation and the enhanced ionization of the molecule, we observed a few-femtosecond time delay between the two dissociation channels for both H_{2} and D_{2}. The delay was interpreted and reproduced by a classical model that considers enhanced ionization and thus additional interaction within the laser pulse. We demonstrate that by accurately measuring the phase of the rotational wave packet in hydrogen molecules we can resolve dissociation dynamics which is occurring within a fraction of a molecular rotation. Such a rotational clock is a general concept applicable to sequential fragmentation processes in other molecules.