Ultrafast dynamics of correlation bands following XUV molecular photoionization

• Published in: Nature physics 2021-03, Vol.17 (3), p.327-331
• Main Authors: Hervé, M., Despré, V., Castellanos Nash, P., Loriot, V., Boyer, A., Scognamiglio, A., Karras, G., Brédy, R., Constant, E., Tielens, A. G. G. M., Kuleff, A. I., Lépine, F.
• Format: Article
• Language: English
• Subjects: 140/125; 639/766/36/1121; 639/766/36/2796; Atomic; Chemical composition; Chemical Sciences; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; Correlation; Electrons; Energy; Engineering Sciences; Experiments; Interstellar chemistry; Interstellar matter; Ionization; Letter; Lifetime; Mathematical and Computational Physics; Molecular; Molecular relaxation; Optical and Plasma Physics; Phonons; Photoionization; Physics; Physics and Astronomy; Polycyclic aromatic hydrocarbons; Radiation; Radiation detectors; Scattering; Theoretical
• ISSN: 1745-2473; 1745-2481; 1476-4636
• DOI: 10.1038/s41567-020-01073-3

Modern ultrashort X-ray/XUV (extreme ultraviolet) sources provide unique opportunities to investigate the primary reactions of matter upon energetic excitation. Understanding these processes in molecules on ultrafast timescales is required to improve bespoke high-energy radiation detectors, nanomedicine schemes or to study the molecular composition of interstellar media. However, current experiments struggle to provide a general framework because of the uniqueness and complexity of each system. Here we show the universal role of correlation bands—features created by electron correlation. This is done by studying ultrafast energy relaxation of size-scalable two-dimensional molecules following ionization by an ultrashort XUV pulse. We observed long lifetimes that nonlinearly increase with the number of valence electrons. A general law based on solid-like electron–phonon scattering is proposed, which explains both our results and previously reported measurements. This offers new opportunities in attosecond science and high-energy photophysics. The size-dependent lifetimes observed in the ultrafast molecular relaxation dynamics of an entire class of polycyclic aromatic hydrocarbons can be explained by correlation bands and electron–phonon scattering, reminiscent of solid-state systems.