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

Appl. Phys. A 69 (1999) pp. 503-506

Surface-state linewidth from scanning tunnelling spectroscopy

Richard Berndt

2. Physikalisches Institut, RWTH Aachen, D-52056 Aachen, Germany

Jiutao Li and Wolf-Dieter Schneider

Institut de Physique Experimentale, Universite de Lausanne, CH-1015 Lausanne, Switzerland

S. Crampin

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

Abstract
The STM can be used to investigate lifetimes of hot holes in a surface state at low temperatures. We analysed dI/dV data from a Ag(111) using detailed tunnelling calculations and a simple model and found an electron self-energy of Sigma=4.9 +/- 0.6 meV. The corresponding lifetime tau = 67 +/- 8 fs is considerably higher than those determined by angle-resolved photoemission, although it remains below theoretical predictions. Spatially resolved dI/dV spectra reveal that the lifetime decreases drastically in proximity to defects such as surface steps.