Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 12: Postersitzung (Struktur und Dynamik reiner Oberfl
ächen, Grenzfl
äche fest-flüssig, Nanostrukturen, Teilchen und Cluster, Halbleiteroberfl
ächen und Grenzfl
ächen, Zeitaufgelöste Spektroskopie, Rastersondentechniken, Methodisches)

O 12.38: Poster

Montag, 24. März 2003, 18:00–21:00, P1

Theoretical models for the transfer of image-state electrons through Ar spacer layers — •W. Berthold1, U. Höfer1, P. Feulner2, C. Marinica3, A. Borisov3, J.-P. Gauyacq3, M. Machado4, E. Chulkov4, and P. Echenique41Fachbereich Physik, Philipps-Universtät, D-35032 Marburg — 2Physik-Department E20, Technische Universtät München, D-85748 Garching — 3Laboratoire des Collisions Atomiques et Moléculaires, Université Paris-Sud, 91405 Orsay Cedex, France — 4Donostia International Physics Center, 20018 San Sebastián, Spain

We have investigated the image-potential states of Cu(100) in the presence of Ar spacer layers as prototype for electron transfer processes through thin, insulating dielectric layers. We demonstrate that a detailed quantitative comparison of experimental results is possible for this well-defined, simple system. Our time-resolved two-photon photoemission (2PPE) experiments show that films with thicknesses of only a few monolayers decouple the image-potential states efficiently from the metal surface and result in lifetime increases of up to three orders of magnitude. A parameterized one-dimensional atomic potential results in a bulk penetration of the image-state wavefunction as a function of layer thickness that scales like the measured lifetimes. Absolute lifetimes are reproduced by GW many-body calculations using this potential. Finally, a three-dimensional parameter-free treatment of the Ar layers is considered. The results of wave-packet propagation methods are compared with the measured lifetime and dispersion of the states.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2003 > Dresden