title: Quantum coherence of image-potential states.
abstract: The quantum dynamics of the two-dimensional image-potential states in front of the Cu(100) surface is measured by scanning tunneling microscopy and spectroscopy. The dispersion relation and the momentum resolved phase-relaxation time of the first image-potential state are determined from the quantum interference patterns in the local density of states at step edges. It is demonstrated that the tip-induced Stark shift does not affect the motion of the electrons parallel to the surface.
authors.affiliation: Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Wahl
authors.forename: M A
authors.initials: MA
authors.lastname: Schneider
authors.forename: L
authors.initials: L
authors.lastname: Diekhöner
authors.forename: R
authors.initials: R
authors.lastname: Vogelgesang
authors.forename: K
authors.initials: K
authors.lastname: Kern