Attosecond photoelectron spectroscopy using high-harmonic generation and seeded free-electron lasers

Speaker: Ioannis Makos (Albert-Ludwigs University Freiburg, Sansone Group)

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Title: Attosecond photoelectron spectroscopy using high-harmonic generation and seeded free-electron lasers

Speaker: GHE Fellow Ioannis Makos, (Albert-Ludwigs University Freiburg, Sansone Group)

Date: December 13th 2023 @ 17:15

Place: University of Basel, Departement Physik, New lecture hall 1

Abstract:

“What is the timescale of photoionization?” Before the advent of attosecond science, it was commonly assumed to be instantaneous, with research focusing on energetics in photoelectron spectroscopy. The groundbreaking work of this year’s Nobel laureates has reshaped our understanding of atomic photo-emission dynamics. They unveiled that the complex dynamics upon photoionization result in a small time delay on the order of tens of attoseconds.
In our study, we employ attosecond photoelectron interferometry to explore photoionization dy-namics at its natural timescale, utilizing both high harmonic generation (HHG) and seeded free-electron lasers to generate extreme ultraviolet (XUV) attosecond pulse trains.
Our lab-based studies using HHG, focus on molecular dynamics upon photoionization, investigat-ing electron correlation effects and the interplay of electron-nuclear motions. Our approach combines two-color interferometric methods with photoelectron-photoion coincidence spectroscopy, allowing for angle-resolved studies in the recoil frame and providing insights into molecular potential anisotro-py.
Using seeded free-electron lasers, we introduce a novel attosecond timing tool for single-shot char-acterization of the relative phase between XUV and the infrared field, essential to perform interfero-metric studies. Implementing our approach, we demonstrate attosecond coherent control of electronic wave packet released in the process of two-color photoionization.