Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 72: [MA] Joint Session "Surface Magnetism III" (jointly with O)

O 72.13: Vortrag

Donnerstag, 29. März 2012, 18:30–18:45, BH 243

First-principles investigation of energy– and impurity–dependent electron focusing effect — •Mohammed Bouhassoune, Peter H. Dederichs, Stefan Blügel, and Samir Lounis — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany

It has been shown recently that the electronic signature of subsurface impurities can be revealed using Scanning Tunneling Spectroscopy (STS) [1,2]. A single impurity buried below the surface induces anisotropic spatial oscillations of the charge density due to a focused coherent interference of scattered electrons. These oscillations whose strength is determined by the shape of the host Fermi surface can be observed at the surface even if the impurity is far below the substrate. Using the full-potential Korringa-Kohn-Rostoker Green-function (KKR-GF) method, we investigate the energy dependent scattering of electrons at several magnetic and non-magnetic buried impurities below the Cu(100) surface. This allows a real-space mapping of the constant energy surfaces of the host material and a possible characterization of the impurity through the analysis of the induced phase shifts of the electron-density oscillations.

This work is supported by the HGF-YIG Programme FunSiLab – Functional Nanoscale Structure Probe and Simulation Laboratory (VH-NG-717).

[1] A. Weismann et al., Science 323, 1190 (2009).

[2] S. Lounis et al., Phys. Rev. B 83, 035427 (2011) and references therein.