[Abstract list] [Previous] [Next] [Home]

Phys. Rev. B 71 155417 (2005).

Electron dynamics in vacancy islands: scanning tunnelling spectroscopy on Ag(111)

H. Jensen, J. Kröger, and R. Berndt

Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany

S Crampin

Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom

Abstract
The dynamics of Ag(111) surface state electrons confined to nanoscale hexagonal and triangular vacancy islands have been investigated using scanning tunneling spectroscopy. We find that the lifetimes of quantised states with significant amplitude near the centers of the vacancies are only weakly affected by the geometry of the confining cavity. A theoretical model is used to describe the dependence of the lifetime on electron energy, vacancy size, step reflectivity and the phase coherence length due to inelastic electron-electron and electron-phonon scattering. Lossy scattering is found to be the dominant lifetime-limiting process for Ag(111) surface vacancy islands with areas in the range 40-220 nm².