Abstract
By fully relativistic first principles calculations, we predict that appropriate strain engineering of layered GaX (, 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.
- Received 13 December 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.266805
© 2012 American Physical Society