Quantum anomalous Hall states in Li/Na-doped kagome V3X8 (X = Cl, Br) monolayers

Abstract

The quantum anomalous Hall (QAH) insulators have great potential in low-energy electronic devices due to their dissipationless conducting channels. By carrying first-principles calculations, we predict that Li/Na-doped two-dimensional kagome lattice V₃X₈ (X = Cl, Br) monolayers, V₃X₈@Li(Na), are intrinsically ferromagnetic (FM) half-semimetals with out-of-plane magnetic anisotropy. Interestingly, the V₃X₈@Li(Na) monolayers exhibit QAH effect with Chern number of C = 1, and a topological phase transition from C = 1 to C = -1 occurs when rotating the magnetization direction from z axis to -z axis. Moreover, the magnetic and topological properties of V₃X₈@Li(Na) monolayers can be further modulated by biaxial strains, and FM QAH insulator and antiferromagnetic (AFM) semiconductor transition can be emerged. Our work provides that V₃X₈@Li(Na) monolayers can serve as materials for exploring novel QAH physics.