%0 Conference Paper
%A Rüssmann, Philipp
%A Aboulouz, Emad
%A Long, Nguyen Hoang
%A Mavropoulos, Phivos
%A Blügel, Stefan
%T KKR-Green function approach to time-reversal scattering off surface impurities in Bi$_2$Te$_3$
%M FZJ-2015-02484
%D 2015
%X In structure inversion-asymmetric environments such as surfaces and interfaces the spin of quasiparticles can have a profound effect on their interference. Quasiparticle interference patterns measured typically by scanning tunneling microscopy are not related in a trivial way to the dispersion of the electronic states. In fact, for Bi(110) [1] it could be shown that the observed interference patterns can be interpreted only by taking spin-conserving scattering events into account. In this contribution we go one step further and include explicitly in the analysis the scattering of the helical surface state electrons off single non-magnetic and magnetic impurities at the surface of the strong topological insulator Bi2Te3. As a matter of principle, magnetic impurities at surfaces break the protection against backscattering. We study this loss of protection by density-functional calculations of the quasiparticle interference at surfaces due to scattering, taking into account time-reversed transitions caused by the magnetic moment. Finally we will also comment on the effect of impurities in the bulk with a focus on the emergence of impurity bands. In our calculations we employ the KKR-Green function method for the electronic structure and scattering properties at defects [2, 3]. We acknowledge financial support from the DFG (SPP-1666) and from the VITI project  (DBB01126) of the Helmholtz Association and computational support from the JARA-HPC Supercomputing Centre at the RWTH Aachen University. References       [1]     J.I. Pascual, G. Bihlmayer, Yu. M. Koroteev, H.-P. Rust, G. Ceballos, M. Hansmann, K. Horn, E. V. Chulkov, S. Blügel, P. M. Echenique, and Ph. Hofmann Phys. Rev. Lett. 93, 196802 (2004)       [2]     S. Heers, PhD Thesis, RWTH Aachen (2011); D.S.G. Bauer, PhD Thesis, RWTH Aachen (2013), B. Zimmerman, PhD Thesis, RWTH Aachen (2014)       [3]     N. H. Long, P. Mavropoulos, B. Zimmermann, D. S. G. Bauer, S. Blügel, and Y. Mokrousov, Phys. Rev. B 90, 064406 (2014)
%B 584. WE-Heraeus-Seminar on 'Green's Functions in ab initio Electronic Structure Calculations of Solids: From Implementations to Applications''
%C 9 Feb 2015 - 11 Feb 2015, Bad Honnef (Germany)
Y2 9 Feb 2015 - 11 Feb 2015
M2 Bad Honnef, Germany
%F PUB:(DE-HGF)24
%9 Poster
%U https://juser.fz-juelich.de/record/189306