Composition-dependent magnetism in intrinsic magnetic topological insulators

Topological materials (TMs) have attracted great research interest with the promise of developing novel electronic devices with new functionalities. Among these materials, MnBi2Te4 is the first intrinsic magnetic topological insulator (TI) that can experimentally achieve quantized edge conductance at certain thicknesses. Here, we propose a systematic study on the magnetism of the extended TI family of MnBi2Te4, i.e., (MnTe)m(Bi2Te3)n, which all possess topologically protected surface states. Further, by substitutional replacement of Bi with Sb, the surface Dirac point can be moved close to the Fermi level, allowing for tracking the interplay between doping and magnetic properties. This composition-ratio dependent study will help to reveal the intimate relation between topology and magnetism in intrinsic magnetic TIs, and therefore promote the development of high-efficiency spintronic applications in TMs.