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arXiv · 1012.3974

Ternary Tetradymite Compounds as Topological Insulators

Lin-Lin Wang·Duane D. Johnson
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Abstract

Ternary tetradymites Bi2Te2S, Bi2Te2Se and Bi2Se2Te are found to be stable, bulk topological insulators via theory, showing band inversion between group V and VI pz orbitals. We identify Bi2Se2Te as a good candidate to study massive Dirac Fermions, with a (111) cleavage-surface-derived Dirac point (DP) isolated in the bulk band gap at the Fermi energy Ef like Bi2Se3 but with a spin texture alterable by layer chemistry. In contrast, Bi2Te2S and Bi2Te2Se (111) behave like Bi2Te3, with a DP below Ef buried in bulk bands. Bi2Te2S offers large bulk resistivity needed for devices.

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Lin-Lin Wang, Duane D. Johnson. 2011-06-23. Ternary Tetradymite Compounds as Topological Insulators. https://doi.org/10.1103/physrevb.83.241309

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