Theoretical prediction of topological insulators in thallium-based III-V-VI2 ternary chalcogenides
Theoretical prediction of topological insulators in thallium-based III-V-VI2 ternary chalcogenides
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DOI：
10.1209/0295-5075/90/37002
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
Binghai Yan;Chaoxing Liu;Hai-Jun Zhang;C. Yam;X. Qi;T. Frauenheim;Shoucheng Zhang
中科院分区：
文献类型：
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作者：
Binghai Yan;Chaoxing Liu;Hai-Jun Zhang;C. Yam;X. Qi;T. Frauenheim;Shoucheng Zhang
我们预测了Tl基III-V-VI2三元硫系化合物中一类新的三维拓扑绝缘体，包括TlBiQ2和TlSbQ2(Q=Te，Se和S)。这些拓扑绝缘体具有坚固而简单的表面态，由Γ点处的单个狄拉克锥体组成。用第一性原理计算和有效场论模型解释了拓扑绝缘行为的机理。值得注意的是，在这类拓扑绝缘体中，TlBiTe2在掺杂p型载流子时也是超导体。我们讨论了这种材料可能是拓扑超导体的可能性。另一种材料TlSbS2位于拓扑绝缘体和平凡的绝缘体相之间，其中的拓扑相变可以由压力驱动。
We predict a new class of three-dimensional topological insulators in thallium-based III-V-VI2 ternary chalcogenides, including TlBiQ2 and TlSbQ2 (Q=Te, Se and S). These topological insulators have robust and simple surface states consisting of a single Dirac cone at the Γ point. The mechanism for topological insulating behavior is elucidated using both first-principle calculations and effective field theory models. Remarkably, one topological insulator in this class, TlBiTe2, is also a superconductor when doped with p-type carriers. We discuss the possibility that this material could be a topological superconductor. Another material, TlSbS2, is on the border between topological insulator and trivial insulator phases, in which a topological phase transition can be driven by pressure.