Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 63: Topological Insulators: Theory (organized by HL)

TT 63.4: Vortrag

Mittwoch, 2. April 2014, 10:15–10:30, POT 151

Nontrivial Interface States Confined Between Two Topological Insulators — •Tomáš Rauch¹, Markus Flieger¹, Jürgen Henk¹, and Ingrid Mertig^1,2 — ¹Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany — ²Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle (Saale), Germany

By ab initio-based tight-binding calculations, we show that nontrivial electronic states exist at an interface of a Z₂ topological insulator and a topological crystalline insulator. At the exemplary (111) interface between Bi₂Te₃ and SnTe, the two Dirac surface states at the Brillouin zone center Γ annihilate upon approaching the semi-infinite subsystems but one topologically protected Dirac surface state remains at each time-reversal invariant momentum M. This leads to a highly conducting spin-momentum-locked channel at the interface but insulating bulk regions. For the Sb₂Te₃/Bi₂Te₃ interface we find complete annihilation of Dirac states because both subsystems belong to the same topology class.