We bring forth a consistent theory for the electron-mediated vibrational intermode coupling that clarifies the microscopic mechanism behind the vibrational relaxation of adsorbates on metal surfaces. Our analysis points out the inability of state-of-the-art nonadiabatic theories to quantitatively reproduce the experimental linewidth of the CO internal stretch mode on Cu(100) and it emphasizes the crucial role of the electron-mediated phonon-phonon coupling in this regard. The results demonstrate a strong electron-mediated coupling between the internal stretch and low-energy CO modes, but also a significant role of surface motion. Our nonadiabatic theory is also able to explain the temperature dependence of the internal stretch phonon linewidth, thus far considered a sign of the direct anharmonic coupling.
@article{arxiv.1803.06302,
title = {Electron-mediated phonon-phonon coupling drives the vibrational relaxation of CO on Cu(100)},
author = {Dino Novko and Maite Alducin and Joseba Iñaki Juaristi},
journal= {arXiv preprint arXiv:1803.06302},
year = {2018}
}
Comments
Article as accepted for publication in Physical Review Letters