Topological Phase Transition in Layered GaS and GaSe

Abstract
By fully relativistic first principles calculations, we predict that appropriate strain engineering of layered GaX (X=S, Se) leads to a new class of three-dimensional topological insulators with an excitation gap of up to 135 meV. Our results provide a new perspective on the formation of three-dimensional topological insulators. Band inversion can be induced by strain only, without considering any spin-orbit coupling. The latter, however, is indispensable for the formation of local band gaps at the crossing points of the inverted bands. Our study indicates that three-dimensional topological insulators can also be realized in materials which comprise light elements only.

Citation
Zhu Z, Cheng Y, Schwingenschlögl U (2012) Topological Phase Transition in Layered GaS and GaSe. Physical Review Letters 108. doi:10.1103/PhysRevLett.108.266805.

Publisher
American Physical Society (APS)

Journal
Physical Review Letters

DOI
10.1103/PhysRevLett.108.266805

PubMed ID
23005005

Additional Links
http://link.aps.org/doi/10.1103/PhysRevLett.108.266805

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