Femtosecond x-ray absorption spectroscopy of pyrazine at the nitrogen K-edge

• Verfasst von: Freibert, Antonia [VerfasserIn]
• Verfasst von: Mendive-Tapia, David [VerfasserIn]
• Verfasst von: Huse, Nils [VerfasserIn]
• Verfasst von: Vendrell, Oriol [VerfasserIn]
• Titel: Femtosecond x-ray absorption spectroscopy of pyrazine at the nitrogen K-edge
• Titelzusatz: on the validity of the Lorentzian limit
• Verf.angabe: Antonia Freibert, David Mendive-Tapia, Nils Huse and Oriol Vendrell
• Jahr: 2021
• Fussnoten: Published 11 February 2022 ; Gesehen am 17.03.2022
• Titel Quelle: Enthalten in: Journal of physics / B
• Ort Quelle: Bristol : IOP Publ., 1988
• Jahr Quelle: 2021
• Band/Heft Quelle: 54(2021), 24 vom: Dez., Artikel-ID 244003
• ISSN Quelle: 1361-6455
• DOI: doi:10.1088/1361-6455/ac3846
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1795851082

Abstract

We calculate the femtosecond x-ray absorption spectrum of pyrazine at the nitrogen K-edge including the wavepacket dynamics in both the valence and core-excited state manifolds. We do not invoke the widely used short-time (or Lorentzian) approximation which neglects the nuclear dynamics after the x-ray probe excitation. Instead, we calculate the x-ray-induced polarization in the time-domain where the optical pump as well as x-ray probe pulses are explicitly described. While the non-adiabatic population transfer following the optical excitation is well reproduced in the Lorentzian limit the transient x-ray absorption spectra obtained under this approximation lack some vibronic features, even when considering the short core-hole lifetime of nitrogen. We further demonstrate the effect of an increasingly longer pulse on the observed photo-triggered wavepacket dynamics which are blurred to the point that the x-ray probe response becomes effectively time-independent.