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Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
Ultrafast electronuclear dynamics of H(2) double ionization
Sébastien Saugout1, Christian Cornaggia, Annick Suzor-Weiner
1Laboratoire de Photophysique Moléculaire du CNRS, Université Paris-Sud, Bâtiment 210, F-91405 Orsay, France.
Physical Review Letters
|August 7, 2007
Summary
Ultrafast laser pulses induce double ionization in hydrogen molecules (H2) by electron rescattering, creating excited states that lead to further ionization through autoionization or direct field effects.
Area of Science:
- Quantum dynamics
- Molecular physics
- Strong-field physics
Background:
- Understanding molecular ionization dynamics under intense laser fields is crucial for attosecond science.
- Previous studies often employed approximations like the fixed-nuclei approximation, limiting insights into coupled electronic-nuclear motion.
Purpose of the Study:
- To investigate the ultrafast electronic and nuclear dynamics of H(2) laser-induced double ionization.
- To elucidate the distinct pathways and mechanisms contributing to double ionization beyond the fixed-nuclei approximation.
Main Methods:
- Utilized a time-dependent wave packet approach, moving beyond the fixed-nuclei approximation.
- Analyzed double ionization pathways by tracking the evolution of the total wave function during and after laser pulse interaction.
Main Results:
- Identified electron rescattering as a key process, generating excited molecular states with transient H(+)H(-) character.
- Observed two primary double ionization mechanisms: direct field-induced ionization and decay of short-lived autoionizing states.
- Found distinct signatures in the kinetic energy distribution of ejected protons for each ionization mechanism.
Conclusions:
- The study provides a comprehensive picture of H(2) double ionization dynamics, highlighting the importance of electron-nuclear coupling.
- The identified mechanisms and their signatures offer a pathway for experimental discrimination and further theoretical investigations in strong-field molecular physics.
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