Hannover 2010 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 23: Poster II

A 23.54: Poster

Donnerstag, 11. März 2010, 16:30–19:00, Lichthof

Image-potential states: A hydrogen-like system at metal surfaces — •Jens Güdde and Ulrich Höfer — Fachbereich Physik und Zentrum für Materialwissenschaften, Philipps-Universität, 35032 Marburg, Germany

Image-potential states represents a simple model system for the study of the complicated many-body interaction at solid surfaces. Electrons in these normally unoccupied states are bound perpendicular to the surface due to the potential well consisting of the coulomblike attractive image potential and the repulsive surface barrier. The resulting quantized electronic states form a hydrogenlike Rydberg series converging to the vacuum energy.

We present an overview of recent experiments in which the combination of coherent optical excitation with time- and angle-resolved two-photon photoemission (2PPE) has been used to study the coherent and incoherent dynamics of electrons in image-potential states on metal surfaces with femtosecond time resolution. This includes quantum-beat spectroscopy of image-potential states and resonances, their decoupling by rare-gas layers, and the generation and detection of coherently controlled ultrashort electrical current pulses at surfaces.