Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 81: Topological Insulators I (Joint session of DS, HL, O and TT, organized by HL)
HL 81.1: Vortrag
Donnerstag, 10. März 2016, 14:45–15:00, H10
Topological Dirac Semimetal in strained HgTe — •Tomáš Rauch1, Steven Achilles1, Jürgen Henk1, and Ingrid Mertig1,2 — 1Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany — 2Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle (Saale), Germany
HgTe, one of the most intensively investigated materials in the context of topological insulators, is a semimetal with zero energy band gap when considered as a three-dimensional material. Applying uniaxial strain in [001] direction changes the situation dramatically [1]. Under compressive strain HgTe becomes a strong topological insulator featuring typical Dirac cone shaped surface states at the Γ point of the surface Brillouin zone. On the other hand, applying a tensile strain makes HgTe a topological Dirac semimetal with a pair of doubly-degenerate Dirac cones located along the kz axis of the bulk Brillouin zone.
By combined ab initio and tight-binding electronic structure calculations we investigate the bulk and surface electronic properties of three-dimensional HgTe in the topological Dirac semimetal phase. This includes calculating the bulk band structure, topological invariants, and the electronic structure of the (100) surface, at which the associated non-trivial surface states emerge.
[1] T. Rauch et al., Phys. Rev. Lett. 114, 236805 (2015)