Timothy H. Hsieh, Hsin Lin, Junwei Liu, Wenhui Duan, Arun Bansil, Liang Fu
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.
View original:
http://arxiv.org/abs/1202.1003
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