Half-integer quantum anomalous Hall effect in MnBi₂Te₄ via non-magnetic extension

Within an ab-initio approach, we study the electronic structure and Hall response of the antiferromagnetic topological insulator film of MnBi₂Te₄ in contact with non-magnetic GeBi₂Te₄ (Bi₂Te₃) overlayer. The proposed junction design eliminates the exchange splitting one of the Dirac cones of the MnBi₂Te₄ (0001) thus manifesting a half-integer quantum anomalous Hall phase. The described recipe allows to enlarge temperature of the effect observation, enriches the diversity of topological properties of the MnBi₂Te₄ compound and is appropriate for other layered antiferromagnetic topological insulators. Applying the proposed heterostructure design, the half-quantized Hall phase can be established with employing other overlayer and magnetic topological insulator films.