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| Hauptseite > Publikationsdatenbank > KKR-Green function approach to time-reversal scattering off surface impurities in Bi$_2$Te$_3$ |
| Hauptseite > Publikationsdatenbank > KKR-Green function approach to time-reversal scattering off surface impurities in Bi$_2$Te$_3$ |
| Poster (Other) | FZJ-2015-02484 |
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2015
Abstract: 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)
Keyword(s): Condensed Matter Physics (2nd) ; Materials Science (2nd)
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