Abstract
For a localized vibration of linearly bonded adsorbate with displacement coordinate u interacting with a substrate atom of coordinate v, we propose a new dephasing contribution to the vibrational linewidth arising from the cubic term v by going to fourth-order perturbation theory. Such a contribution is shown through a specific example to be equally as important as the leading-order dephasing contribution of the quartic term , which has been considered by others. It is shown that this cubic term produces much stronger sidebands than the quartic term; it is suggested that this fact may be used in some cases to verify or eliminate phonon dephasing as the linewidth mechanism.
- Received 5 August 1987
DOI:https://doi.org/10.1103/PhysRevLett.59.2211
©1987 American Physical Society