Two-dimensional kagome lattice Zn2N3 as an intrinsic magnetic topological insulator for quantum anomalous Hall effect

Magnetic topological insulators (Chern insulators) have been extensively sought since quantum anomalous Hall effect (QAHE) was experimentally verified. Here, we employ first-principles calculations to predict a kagome lattice Zn2N3 monolayer to be an intrinsic magnetic topological insulator which makes QAHE to be realized. The stable Zn2N3 monolayer is shown to exhibit a large band gap of 3.75 eV in a spin channel and a well known Weyl point near the Fermi level with the Fermi velocity of about 4.2 × 105 m s−1 in the other spin channel. Further taking into account the spin–orbit coupling (SOC), the system opens a band gap of 4.3 meV at the Fermi level, and the opening of the band gap brings about a surge in the Berry curvature, which transforms the system into a topological non-trivial state. In addition, the Zn2N3 belongs to the ferromagnetic ground state with out of plane magnetization, and the Curie temperature (Tc) is estimated to be 168 K by Monte Carlo simulation. Moreover, the tight-binding (TB) model is established to verify the topological properties with the calculated Chern number C = 1, anomalous Hall conductance (AHC) σxy=e2/h, and a dissipation-free chiral edge state. Thus, the kagome Zn2N3 monolayer could be a potential candidate for achieving QAHE and low-power consumption spintronic devices.