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O: Oberflächenphysik

O 19: Electronic structure II

O 19.2: Vortrag

Dienstag, 28. März 2006, 11:30–11:45, WIL A317

Image-Potential States of Reconstructed Au(100) — •M. Alexander Schneider, Gero Wittich, Lucia Vitali, and Klaus Kern — Max-Planck-Institute for Solid State Research, 70569 Stuttgart, Germany

Electrons in image-potential states form an exemplary two-dimensional electron gas at the surface of many metals. As the major weight of the electron wavefunctions is found in the vacuum region they are attractive for studying the mechanisms limiting electron lifetimes which are larger than that of other electronic states in metal systems.
However, despite the low overlap with the surface region of a crystal, defects at surfaces modify the electronic states considerably. This is demonstrated in a low-temperature Scanning Tunneling Spectroscopy (STS) study of the image-potential states of reconstructed Au(100) (5x27). The interaction with the reconstruction introduces band-gaps in the dispersion of the image-potential states and causes a spatial anisotropy of the image potential states. STS allows to study the behavior of the electrons at defects like dislocations or step edges. We will discuss to what extent the (scattering) surface potential can be reconstructed from STS measurements.