Dresden 2014 – scientific programme
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O: Fachverband Oberflächenphysik
O 42: Topological Insulators: Theory (HL jointly with MA, O, TT)
O 42.5: Talk
Wednesday, April 2, 2014, 10:30–10:45, POT 151
Natural three-dimensional topological insulators in Tl4PbTe3 and Tl4SnTe3 — •Chengwang Niu1,2, Ying Dai1, Baibiao Huang1, Gustav Bihlmayer2, Yuriy Mokrousov2, Daniel Wortmann2, and Stefan Blügel2 — 1School of Physics, Shandong University, Jinan, China — 2Peter Grünberg Institut (PGI-1) & Institute for Advanced Simulation (IAS-1), Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
The recently discovered three-dimensional topological insulators have attracted much interest due to their exceptional properties of possessing insulating bulk but time-reversal symmetry protected metallic surfaces with Dirac-like band structure [1,2]. The search for new topological insulators is critical for both fundamental and practical interests. Based on first-principles calculations, we reveal that both Tl4PbTe3 and Tl4SnTe3 are strong topological insulators with different band inversion behaviors at Γ point [3]. The mechanisms of band inversion in Tl4PbTe3 and Tl4SnTe3, as well as in Bi2Se3 and Sb2Se3, are investigated and classified. The Z2 topological invariants and topological surface states are investigated to confirm the topologically non-trivial phase. Our calculations further indicate that the electron- or hole-type Dirac fermion can be effectively engineered by hole doping, which is necessary for device applications of topological insulators.
[1] M. Hasan and C. Kane, Rev. Mod. Phys. 82, 3045 (2010).
[2] X.-L. Qi and S.-C. Zhang, Rev. Mod. Phys. 83, 1057 (2011).
[3] C. Niu et al., in preparation.