A phase diagram for band inversion of topological materials as a function of interactions between two involved bands

Surface Physics Laboratory (National Key Laboratory), Key Laboratory of Computational Physical Sciences (MOE), Department of Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University Shanghai 200433, PRC

^(a) jgche@fudan.edu.cn (corresponding author)

Received: 19 October 2015
Accepted: 14 January 2016

Abstract

Basing on first-principles calculations, we predicate that Bi on a graphene derivative, g-C₁₄N₃, which involves a 3 × 3 unit cell of graphene with four C atoms substituted by three N atoms, is a topological insulator with a gap of 50 meV. With the help of maximally localized Wannier functions, we find that its band inversion gap can be determined by examining a pair of interaction parameters between the two involved bands. Accordingly, a phase diagram for band inversion of topological materials as a function of the interactions is obtained. The conclusion also holds for Sb, Ir and Rh on g-C₁₄N₃. These materials are topological nontrivial either insulator or semimetal, indicating that g-C₁₄N₃ is a good platform for conceiving topological materials.