Berlin 2015 – scientific programme
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O: Fachverband Oberflächenphysik
O 51: Topological Insulators: Theory (HL with DS/MA/O/TT)
O 51.6: Talk
Wednesday, March 18, 2015, 10:45–11:00, ER 270
Quasiparticle band structure of the topological insulator Bi2Se3 — •Tobias Förster, Peter Krüger, and Michael Rohlfing — Institut für Festkörpertheorie, Westfälische Wilhelms-Universität, 48149 Münster, Germany
Bi2Se3 is a prototype topological insulator. Its simple surface band structure with only one Dirac point makes it an ideal system for exploring the properties of topological surface states. Up to now, the vast majority of theoretical investigations of the electronic structure of Bi2Se3 has utilized DFT calculations. In Bi2Se3 and related compounds, however, many body perturbation theory in the GW approximation yields both quantitative and qualitative quasiparticle corrections of the DFT bulk band structures [1].
Here we discuss results for bulk Bi2Se3 from GW calculations employing a localized basis as well as from a perturbative LDA+GdW approach [2]. The latter provides a numerically very efficient method for the calculation of quasiparticle corrections with only slightly reduced precision compared to GW. The applicability of the LDA+GdW formalism to the Bi2Se3 surface with the Dirac state will also be addressed.
[1] I. Aguilera et al., Phys. Rev. B 88, 045206 (2013)
[2] M. Rohlfing, Phys. Rev. B 82, 205127 (2010)