Single Cs atoms adsorbed on Ag(111) induce a resonance appearing just below the threshold of the quasi-two-dimensional Shockley-type surface-state continuum. Spectroscopic analysis using a cryogenic scanning tunneling microscope and theoretical modeling are used to identify the importance of the various contributions to the linewidth and to the decay of the resonance: resonant charge transfer, inelastic transitions, and adsorbate vibrations perpendicular to the surface.

• Received 18 December 2008

DOI:https://doi.org/10.1103/PhysRevB.79.075401