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O: Fachverband Oberflächenphysik

O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)

O 60.102: Poster

Wednesday, March 16, 2011, 17:30–21:00, P4

Theoretical approach to adatom structures on semiconductor surfaces: Ab-initio studies and explicit many-body extensions. — •Sergej Schuwalow and Frank Lechermann — I. Institut für Theoretische Physik, Universität Hamburg, D-20355 Hamburg, Deutschland

Single adatoms, dimers and general quasi-twodimensional adsorbate arrays on semiconductor surfaces exhibit a great variety of interesting effects, while having the advantage of being directly accessible via surface-sensitive experimental probe techniques. The reduced dimensionality and the coupling to the substrate can produce, e.g., peculiar magnetic effects and also correlation effects may become important due to strong electron localization at the adatom sites.

Within this work, we investigate the electronic structure of submonolayer surface systems, namely the Sn/Si(111) and the Sn/Ge(111) alpha surfaces [1], as well as single magnetic adatoms (Fe,Co,Ni) on the InSb(110) substrate [2] by density-functional theory (DFT) and, where appropriate, its combination with explicit many-body methods. Our main focus lies on determining the structural, bonding and magnetic properties, and in case of the Sn submonolayer systems, the influence of a finite Hubbard U on the surface states.

[1] Sergej Schuwalow, Daniel Grieger, Frank Lechermann, Phys. Rev. B 82, 035116 (2010)

[2] A. A. Khajetoorians, B. Chilian, J. Wiebe, S. Schuwalow, F. Lechermann and R. Wiesendanger, Nature 467, 1084 (2010)