Monitoring Valence-electron Dynamics In Molecules With Ultrafast X-ray Diffraction

Yong, Haiwang

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https://hdl.handle.net/2142/116684 Copy

Description

Title

Monitoring Valence-electron Dynamics In Molecules With Ultrafast X-ray Diffraction

Author(s)

Yong, Haiwang

Contributor(s)

• Mukamel, Shaul
• Cavaletto, Stefano M.

Issue Date

2022-06-21

Keyword(s)

Mini-symposium: Spectroscopy meets Chemical Dynamics

Abstract

Ultrafast x-ray diffraction has been used to directly observe excited state electron density distributions in molecule upon photoexcitation (1). Theoretical studies have shown that its signal contains mixed elastic-inelastic coherence term originating from electronic coherence (2,3). In this study, we present a simulation study of valence-electron dynamics of oxazole using time-resolved off-resonant x-ray diffraction (4). A valence-state electronic wavepacket is prepared with an attosecond soft x-ray pulse through a stimulated resonant x-ray Raman process (5), and then probed with off-resonant single-molecule x-ray diffraction. We find that the time dependent diffraction signal originates solely from the electronic coherences and can be detected by existing experimental techniques. The present study thus provides a practical way of imaging electron dynamics in free molecules. In addition, the created electronic coherences and subsequent electron dynamics can be manipulated by resonant x-ray Raman excitations tuned to different core-excited states. (1) H. Yong, N. Zotev, J. M. Ruddock, B. Stankus, M. Simmermacher, A. Moreno Carrascosa, W. Du, N. Goff, Y. Chang, D. Bellshaw, M. Liang, S. Carbajo, J. E. Koglin, J. S. Robinson, S. Boutet, M. P. Minitti, A. Kirrander, P. M. Weber, Observation of the molecular response to light upon photoexcitation. Nat. Commun. 11 , 2157 (2020) (2) K. Bennett, M. Kowalewski, J. R. Rouxel, S. Mukamel, Monitoring molecular nonadiabatic dynamics with femtosecond x-ray diffraction. Proc. Natl. Acad. Sci. U.S.A. 115 , 6538-6547 (2018). (3) M. Simmermacher, N. E. Henriksen, K. B. Moller, A. Moreno Carrascosa, A. Kirrander, Electronic coherence in ultrafast x-ray scattering from molecular wave packets. Phys. Rev. Lett. 122, 073003 (2019). (4) H. Yong, S. M. Cavaletto, S. Mukamel, Ultrafast valence-electron dynamics in oxazole monitored by x-ray diffraction following a stimulated x-ray Raman excitation. J. Phys. Chem. Lett. 12, 9800-9806 (2021). (5) D. Healion, Y. Zhang, J. D. Biggs, N. Govind, S. Mukamel, Entangled valence electron-hole dynamics revealed by stimulated attosecond x-ray Raman scattering. J. Phys. Chem. Lett. 3, 2326-2331 (2012).

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116684&&

DOI

https://doi.org/10.15278/isms.2022.TA04

Copyright and License Information

Copyright 2022 held by the authors

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