We Report a Combined Experimental and Theoretical Study on the Effect of Autoionizing Resonances in Time-Resolved Photoelectron Spectroscopy. the Coherent Excitation of N2 by ∼14.15 EV Extreme-Ultraviolet Photons Prepares a Superposition of Three Dominant Adjacent Vibrational Levels (V′=14-16) in the Valence B′ ςu+1 State, Which Are Probed by the Absorption of Two or Three Near-Infrared Photons (800 Nm). the Superposition Manifests itself as Coherent Oscillations in the Measured Photoelectron Spectra. a Quantum-Mechanical Simulation Confirms that Two Autoionizing Rydberg States Converging to the Excited a Π2u and B ςu+2 N2+ Cores Are Accessed by the Resonant Absorption of Near-Infrared Photons. We Show that These Resonances Apply Different Filters to the Observation of the Vibrational Wave Packet, Which Results in Different Phases and Amplitudes of the Oscillating Photoelectron Signal Depending on the Nature of the Autoionizing Resonance. This Work Clarifies the Importance of Resonances in Time-Resolved Photoelectron Spectroscopy and Particularly Reveals the Phase of Vibrational Quantum Beats as a Powerful Observable for Characterizing the Properties of Such Resonances.




U.S. Department of Energy, Grant 200021_172946

International Standard Serial Number (ISSN)

1079-7114; 0031-9007

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2023 American Physical Society, All rights reserved.

Publication Date

14 Apr 2023

Included in

Physics Commons