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SYUO: Ultrakurzzeitdynamik an Oberflächen
SYUO 2: Ultrakurzzeitdynamik II (1)
SYUO 2.1: Invited Talk
Thursday, March 30, 2000, 12:00–12:30, H45
Self-energy and inelastic lifetimes of surface states in metals — •P.M. Echenique1, E.V. Chulkov1,2, and J.M. Pitarke2,3 — 1Materialen Fisika Saila, Kimika Fakultaten, Euskal Herriko Unibertsitaten, 1072 Posta kutxatily, 20080 Donostia, Basque Country, Spain — 2Donostia International Physics Center (DIPC) and Centro Mixto CSIC-UPV/EHU, Donostia, Basque Country, Spain — 3Maeria Kondentsatuaren Fisika, Zientzi Fakultatea, Euskal Herriko Unibertsitatea, 644 Posta kutxatila, 48080 Bilbo, Basque Country, Spain
A metal surface generates electron states that do not exist in a bulk metal. These so-called surface states can be classified into two categories, crystal-induced states and image-potential-induced states, according to whether they are originated from the crystal termination or from the long-range image potential. Here we present a survey of current investigations of the origin of the decay of these surface states. Inelastic lifetimes are obtained from the knowledge of the quasiparticle self-energy, which we compute within the GW approximation of many-body theory by going beyond a free-electron description of the surface. Surface-state lifetimes in a variety of simple and noble metal surfaces are presented. Our results, which are in agreement with recent high-resolution photoemission measurements, show that actual lifetimes are highly sensitive to the details of both the surface response and the wave function of the excited quasiparticle.