Abstract
Attoclock is a powerful technique to resolve laser-driven electron dynamics on an attosecond time scale. Previously, it was mainly limited to atomic targets. Here we apply the attoclock technique to aligned molecules to study the subcycle ionization dynamics. By controlling the alignment of the molecule relative to the major axis of a strong elliptically polarized laser field, we demonstrate that the electron ionization time in aligned molecules can be precisely resolved by the attoclock technique. We find that the ionization time corresponding to the peak of the photoelectron momentum distribution shifts several tens of attoseconds relative to the laser field peak depending on the molecular orientation and molecular orbital structure. A significant difference between the measurement and molecular Ammosov-Delone-Krainov model is found. We further show that the photoelectron ionization time of molecules is sensitive to angular-dependent ionization rate, opening up opportunities for probing attosecond electron dynamics in complex polyatomic molecules.
- Received 6 July 2020
- Accepted 8 July 2020
DOI:https://doi.org/10.1103/PhysRevA.102.013117
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