Atom-Specific Probing of Electron Dynamics in an Atomic Adsorbate by Time-Resolved X-ray Spectroscopy
arXiv:2211.00776 · doi:10.1103/PhysRevLett.129.276001
Abstract
The electronic excitation occurring on adsorbates at ultrafast time scales from optical lasers that initiate surface chemical reactions is still an open question. Here, we report the ultrafast temporal evolution of X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) of a simple well known adsorbate prototype system, namely carbon (C) atoms adsorbed on a nickel (Ni(100)) surface, following intense laser optical pumping at 400 nm. We observe ultrafast (~100 fs) changes in both XAS and XES showing clear signatures of the formation of a hot electron-hole pair distribution on the adsorbate. This is followed by slower changes on a few ps time scale, shown to be consistent with thermalization of the complete C/Ni system. Density functional theory spectrum simulations support this interpretation.
arXiv comment33 pages, 12 figures. Submitted to Physical Review Letters
References in corpus (12)
- Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
- Phonons and related properties of extended systems from density-functional perturbation theory
- Advanced capabilities for materials modelling with Quantum ESPRESSO
- A real-space grid implementation of the Projector Augmented Wave method
- X-ray Absorption Near-Edge Structure calculations with pseudopotentials. Application to K-edge in diamond and alpha-quartz
- Delta Self-Consistent Field as a method to obtain potential energy surfaces of excited molecules on surfaces
- Projector augmented wave calculation of x-ray absorption spectra at the L2,3 edges
- Revealing the nature of the ultrafast magnetic phase transition in Ni by correlating extreme ultraviolet magneto-optic and photoemission spectroscopies
- Electron-phonon coupling and phonon self-energy in MgB: do we really understand MgB Raman spectra ?
- Ultrafast X-Ray Induced Changes of the Electronic and Magnetic Response of Solids Due to Valence Electron Redistribution
- Ultrafast Transient Dynamics of Adsorbates on Surfaces Deciphered: The Case of CO on Cu(100)
- Ultrafast adsorbate excitation probed with sub-ps resolution XAS