Attosecond ionization and electronic decoherence in core levels of isolated molecules and the valence shell of liquid phase water
Manuscript of the thesis
Abstract:
The development of attosecond spectroscopy over the past twenty years has significantly improved our understanding of the ultrafast dynamics involved in the ionization of atoms and molecules. The objective of this thesis was to measure ionization dynamics in molecular systems in both the gas and liquid phases. To investigate these systems, which exhibit complex electronic properties, a dual-spectrometer setup was developed, enabling the analysis of spectral interferometry experiments on complex spectra.
A first study focusing on core-level ionization delays across a broad set of iodine-containing molecules revealed the influence of the chemical environment of the iodine atom on ionization dynamics. While reconciling two previously conflicting measurements, our systematic investigation identified a correlation between ionization delays and the electronegativity of the ligand.
A second study leveraged the development of a vacuum-compatible liquid microjet to demonstrate an ultrafast decoherence process during ionization in the liquid phase, attributed to elastic collisions of the photoelectron within the solvent.
This work paves the way for new studies of attosecond dynamics in molecular systems. Future developments of high-energy, high-repetition-rate attosecond sources will enable detailed investigations of inner-shell electronic correlation effects, giant resonances, autoionization processes, post-collision interactions, and more. Finally, technological advances in liquid-jet sources will make it possible to solvate some of the molecules studied in the gas phase and to explore the combined effects highlighted in this thesis.
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