Nonadiabatic adsorbate vibrational damping and surface electronic structure: H on W(001)

Abstract
Recent infrared-absorption measurements of the vibrations of hydrogen adsorbed on W(001) have provided unambiguous evidence for electronic damping of atomic vibrations on metallic surfaces. This is a simple example of nonadiabatic coupling of a discrete state to a continuum. We describe here selection rules and other criteria for nonadiabatic electronic dampling of adsorbate vibrations and report the observation and characterization, using angle-resolved photoemission, of a surface resonance close to the Fermi level on H-saturated W(001) which satisfies these criteria.