Rocksalt SnS and SnSe: Native topological crystalline insulators
- Author(s)
- Yan Sun, Zhicheng Zhong, Tomonori Shirakawa, Cesare Franchini, Dianzhong Li, Yiyi Li, Seiji Yunoki, Xing-Qiu Chen
- Abstract
Unlike time-reversal topological insulators, surface metallic states
with Dirac cone dispersion in the recently discovered topological
crystalline insulators (TCIs) are protected by crystal symmetry. To
date, TCI behaviors have been observed in SnTe and the related alloys Pb1−xSnxSe/Te, which incorporate heavy elements with large spin-orbit coupling (SOC). Here, by combining first-principles and ab initio
tight-binding calculations, we report the formation of a TCI in
relatively lighter rocksalt SnS and SnSe. This TCI is characterized by
an even number of Dirac cones at the high-symmetry (001), (110), and
(111) surfaces, which are protected by the reflection symmetry with
respect to the (1¯10)
mirror plane. We find that both SnS and SnSe have an intrinsically
inverted band structure even without the SOC and the SOC is necessary
only to open the bulk band gap. The bulk band gap evolution upon volume
expansion reveals a topological transition from an ambient pressure TCI
to a topologically trivial insulator. Our results indicate that the SOC
alone is not sufficient to drive the topological transition.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- Chinese Academy of Sciences (CAS), Ulmer Fundamental Symmetries Laboratory, Technische Universität Wien, Japan Science and Technology Agency
- Journal
- Physical Review B
- Volume
- 88
- No. of pages
- 6
- ISSN
- 1098-0121
- DOI
- https://doi.org/10.1103/PhysRevB.88.235122
- Publication date
- 12-2013
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103009 Solid state physics, 103015 Condensed matter, 103025 Quantum mechanics, 103036 Theoretical physics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/0d56c639-7feb-48c4-91ef-7cf2e46a7c71