Open AccessHigh-resolution x-ray spectra of carbon monoxide reveal ultrafast dynamics induced by long UV pulse
Author(s) -
Ji-Cai Liu,
Viktoriia Savchenko,
Victor Kimberg,
Faris Gel’mukhanov,
Michael Odelius
Publication year - 2021
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/ac0198
Subject(s) - physics , ultrashort pulse , spectral line , excited state , spectral resolution , shutter , atomic physics , pulse (music) , temporal resolution , carbon monoxide , optics , spectroscopy , laser , detector , chemistry , astronomy , biochemistry , quantum mechanics , catalysis
In theoretical simulations of a UV + x-ray pump-probe (UVX-PP) setup, we show that frequency detuning of the pump UV pulse acts as a camera shutter by regulating the duration of the UVX-PP process. This two-photon absorption with long overlapping UV and x-ray pulses, allowing for high spectral resolution, thereby provides information about ultrafast dynamics of the nuclear wave packet without the requirement of ultrashort pulses and controlled delay times. In a case study of carbon monoxide, the calculated UVX-PP spectra of the O1 s −1 2 π 1 and C1 s −1 2 π 1 core-excited states show different vibrational profiles. The interference of intermediate vibrational states reveals details of nuclear dynamics in the UVX-PP process related to a variable duration time controlled by the UV detuning. Both O1 s −1 2 π 1 and C1 s −1 2 π 1 pump-probe channels display a splitting of the spectral profile, which however is associated with different physical mechanisms. At the O1 s −1 2 π 1 resonance, the observed dispersive and non-dispersive spectral bands intersect and result in destructive interference.