Anomalous transient blueshift in the internal stretch mode of CO/Pd(111)
Abstract
In time-resolved pump-probe vibrational spectroscopy the internal stretch mode of polar molecules is utilized as a key observable to characterize the ultrafast dynamics of adsorbates on surfaces. The adsorbates non-adiabatic intermode couplings are the commonly accepted mechanisms behind the observed transient frequency shifts. Here, we study the CO/Pd(111) system with a robust theoretical framework that includes electron-hole pair excitations and electron-mediated coupling between the vibrational modes. A mechanism is revealed that screens the electron-phonon interaction and originates a blueshift under ultrafast non-equilibrium conditions. The results are explained in terms of the abrupt change in the density of states around the Fermi level, and are instrumental for understanding dynamics at multi-component surfaces involving localized and standard or states.
Keywords
Cite
@article{arxiv.2211.12192,
title = {Anomalous transient blueshift in the internal stretch mode of CO/Pd(111)},
author = {Raúl Bombín and Alberto S. Muzas and Dino Novko and J. Iñaki Juaristi and Maite Alducin},
journal= {arXiv preprint arXiv:2211.12192},
year = {2023}
}
Comments
3 figures, 5 pages