Dimensionality Effects in the Lifetime of Surface States
J. Kliewer,
1
R. Berndt,
12*
E. V. Chulkov,
3
V. M. Silkin,
3
P. M. Echenique,
3
S. Crampin
4
A long-standing discrepancy between experimental and theoretical
values for the lifetimes of holes in the surface-state electron bands
on noble metal surfaces is resolved; previous determinations of both
are found to have been in error. The ability of the scanning tunneling
microscope to verify surface quality before taking spectroscopic measurements is used to remove the effects of defect scattering on
experimental lifetimes, found to have been a significant contribution to prior determinations. A theoretical treatment of inelastic electron-electron scattering is developed that explicitly includes intraband transitions within the surface state band. In our model, two-dimensional decay channels dominate the electron-electron interactions that contribute to the hole decay and are screened by the
electron states of the underlying three-dimensional electron system.
1 RWTH Aachen, II. Physikalisches Institut,
D-52056 Aachen, Germany.
2 Institut für
Experimentelle und Angewandte Physik,
Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany.
3 Departamento de Física de Materiales, Facultad de
Química, Universidad del Pais Vasco and Centro Mixto UPV-CSIC
and Donostia International Physics Center, Apdo. 1072, 20080 San
Sebastian, Spain.
4 Department of Physics, University of
Bath, Bath, BA2 7AY, UK.
*
To whom correspondence should be addressed. E-mail:
berndt{at}physik.uni-kiel.de
