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Updated: Mar 2, 2026

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
Electron-Nuclear Coupling through Autoionizing States after Strong-Field Excitation of H_{2} Molecules
Yonghao Mi1, Nicolas Camus1, Lutz Fechner1
1Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
Abstract:
Channel-selective electron emission from strong-field photoionization of H_{2} molecules is experimentally investigated by using ultrashort laser pulses and a reaction microscope. The electron momenta and energy spectra in coincidence with bound and dissociative ionization channels are compared. Surprisingly, we observed an enhancement of the photoelectron yield in the low-energy region for the bound ionization channel. By further investigation of asymmetrical electron emission using two-color laser pulses, this enhancement is understood as the population of the autoionizing states of H_{2} molecules in which vibrational energy is transferred to electronic energy. This general mechanism provides access to the vibrational-state distribution of molecular ions produced in a strong-field interaction.
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