Time-frequency representation of autoionization dynamics in helium

Summary, in English

Autoionization, which results from the interference between direct photoionization and photoexcitation to a discrete state decaying to the continuum by configuration interaction, is a well known example of the important role of electron correlation in light-matter interaction. Information on this process can be obtained by studying the spectral, or equivalently, temporal complex amplitude of the ionized electron wave packet. Using an energy-resolved interferometric technique, we measure the spectral amplitude and phase of autoionized wave packets emitted via the sp2⁺ and sp3⁺ resonances in helium. These measurements allow us to reconstruct the corresponding temporal profiles by Fourier transform. In addition, applying various time-frequency representations, we observe the build-up of the wave packets in the continuum, monitor the instantaneous frequencies emitted at any time and disentangle the dynamics of the direct and resonant ionization channels.

• Author: D. Busto; L. Barreau; M. Isinger; M. Turconi; C. Alexandridi; A. Harth; S. Zhong; R. J. Squibb; D. Kroon; S. Plogmaker; M. Miranda; Jiménez-Galán; L. Argenti; C. L. Arnold; R. Feifel; F. Martín; M. Gisselbrecht; A. L'Huillier; P. Salières
• Department/s: Atomic Physics; MAX IV Laboratory; Synchrotron Radiation Research
• Publishing year: 2018-01-23
• Language: English
• Publication/Series: Journal of Physics B: Atomic, Molecular and Optical Physics
• Volume: 51
• Issue: 4
• Links: http://dx.doi.org/10.1088/1361-6455/aaa057
• Document type: Journal article
• Publisher: IOP Publishing
• Topic: Atom and Molecular Physics and Optics
• Keywords: attosecond pulse; autoionization; Fano resonance; RABBIT; time-frequency representations; Wigner
• Status: Published
• ISBN/ISSN/Other: ISSN: 0953-4075