Doping-induced magnetic and topological transitions in Mn ₂ <i>X</i> ₂ Te ₅ ( <i>X</i> = Bi, Sb) bilayers

Abstract We investigate the magnetic and topological properties of Mn 2 X 2 Te 5 ( X = Bi, Sb) using first-principles calculations. We find that both Mn 2 Bi 2 Te 5 and Mn 2 Sb 2 Te 5 bilayers exhibit A-type antiferromagnetic order, which can be understood based on the Goodenough–Kanamori–Anderson rules. We further find that an appropriate hole doping can induce a transition from the A-type antiferromagnetic phase to the ferromagnetic phase in these systems, which also experience a transition from a normal insulator to a quantum anomalous Hall phase. Our study thus demonstrates that tunable magnetism and band topology can be achieved in Mn 2 X 2 Te 5 , which may be utilized in the design of new functional electronic devices.