Coupling effect of topological states and Chern insulators in two-dimensional triangular lattices

Article

关键词: SPIN HALL INSULATOR;    HGTE QUANTUM-WELLS;    WANNIER FUNCTIONS;    REALIZATION;    SCALE;   

DOI  :  10.1103/PhysRevB.97.125430

来源: SCIE

【 摘 要 】

We investigate topological states of two-dimensional (2D) triangular lattices with multiorbitals. Tight-binding model calculations of a 2D triangular lattice based on p(x) and p(y) orbitals exhibit very interesting doubly degenerate energy points at different positions (Gamma and K/K') in momentum space, with quadratic non-Dirac and linear Dirac band dispersions, respectively. Counterintuitively, the system shows a global topologically trivial rather than nontrivial state with consideration of spin-orbit coupling due to the destructive interference effect between the topological states at the Gamma and K/K' points. The topologically nontrivial state can emerge by introducing another set of triangular lattices to the system (bitriangular lattices) due to the breakdown of the interference effect. With first-principles calculations, we predict an intrinsic Chern insulating behavior (quantum anomalous Hall effect) in a family of the 2D triangular lattice metal-organic framework of Co(C-21 N3H15) (TPyB-Co) from this scheme. Our results provide a different path and theoretical guidance for the search for and design of new 2D topological quantum materials.

【 授权许可】

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