Berlin 2012 – wissenschaftliches Programm
MA 22.7: Vortrag
Mittwoch, 28. März 2012, 11:00–11:15, EB 301
Predicting surface states from the bulk embedding self-energy — •Daniel Wortmann, Gustav Bihlmayer, and Stefan Blügel — Institute for Advanced Simulation & Peter Grünberg Institut, Forschungszentrum Jülich und JARA, 52425 Jülich, Germany
The protected states localized at surfaces and interfaces of topological insulators are a consequence of the electronic structure of the bulk. Their peculiar features like the typical spin-structure makes them an interesting field of basic research with possible applications in spintronics.
We demonstrate how these states can be efficiently simulated by means of the embedding self-energy as obtained in the Green function embedding technique. The embedding self-energy, which can be understood as a generalized logarithmic derivative, is a property of the bulk crystal only and contains all information required to analyze the consequences of the bulk topology on the surface bandstructure. Using the FLAPW implementation of the embedding method as provided in the FLEUR-code, we show how the surface states of prototypical topological insulators like Bi2Se3 can be studied efficiently with an easy and direct access to effects for example due to electric fields applied to the surface.
 D. Wortmann, H. Ishida, S. Blügel. Phys. Rev. B 66, 075113(02)