Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 46: Surface magnetism I (jointly with MA)
O 46.2: Talk
Wednesday, March 16, 2011, 11:30–11:45, CHE 184
Scattering behaviour of single non-magnetic and magnetic impurities buried under a Cu(100) surface — •Henning Prüser1, Martin Wenderoth1, Piet E. Dargel2, Alexander Weismann1, Robert Peters2, Thomas Pruschke2, and Rainer G. Ulbrich1 — 1IV. Physikalische Institut, Georg-August Universität Göttingen, Germany — 2Institut für Theoretische Physik, Georg-August Universität Göttingen, Germany
It has been recently shown [1] that the anisotropy of the copper Fermi surface leads to a strongly directional propagation of quasi particles called electron focusing. This effect gives access to individual bulk impurities in a metal that were previously assumed to be "invisible" due to charge screening. Following this idea we have investigated the energy-dependent scattering characteristics for single isolated atoms of Ag, Co and Fe buried under a Cu(100) surface using low temperature scanning tunnelling spectroscopy (STS). For the case of a non-magnetic Ag impurity a Friedel oscillation in the local density of states is observed. For a magnetic Fe or Co impurity the Kondo effect influences strongly the energy-dependent scattering behaviour. We present a theoretical interpretation of the measured signatures using a combined approach of band structure and many-body numerical renormalization group calculations. The obtained results are in excellent agreement with the rich spatially and spectroscopically resolved experimental data. This work was supported by DFG SFB 602 Project A3.
[1] A. Weismann et al., Science 323, 1190 (2009)