Topological Crystalline Insulators in the SnTe Material Class

Authors:
  • THTimothy H. Hsieh
    Timothy H. Hsieh
  • HLHsin Lin
    Hsin Lin
  • JLJunwei Liu
    Junwei Liu
  • WDWenhui Duan
    Wenhui Duan
  • ABArun Bansil
    Arun Bansil
  • LFLiang Fu
    Liang Fu
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Abstract
Topological crystalline insulators are new states of matter in which the topological nature of electronic structures arises from crystal symmetries. We theoretically demonstrate that SnTe is a topological crystalline insulator due to its intrinsically inverted band structure at four L points in the Brillouin zone. As a consequence, we predict that SnTe has metallic surface states with an even number of Dirac cones on crystal surfaces such as [001] or [111], which are symmetric about the [110] mirror plane. These surface states, exhibited by our first-principles calculations, form a new type of Dirac metal protected by mirror symmetry and robust against disorder. We also find that the related semiconductors PbTe and PbSe become topological crystalline insulators under pressure after their band gaps are inverted.