High-temperature magnetically topological candidate material Mn3Bi2Te6

Abstract

The Mn–Bi–Te family displaying magnetism and non-trivial topological properties has received extensive attention. Here, we predict that the antiferromagnetic structure of Mn3Bi2Te6 with three MnTe layers is energetically stable and the magnetic energy difference of Mn–Mn is enhanced four times compared with that in the single MnTe layer of MnBi2Te4. The predicted Néel transition point is raised to 102.5 K, surpassing the temperature of liquid nitrogen. The topological properties show that with the variation of the MnTe layer from a single layer to three layers, the system transforms from a non-trivial topological phase to a trivial topological phase. Interestingly, the ferromagnetic state of Mn3Bi2Te6 is a topological semimetal and it exhibits a topological transition from trivial to non-trivial induced by the magnetic transition. Our results enrich the Mn–Bi–Te family system, offer a new platform for studying topological phase transitions, and pave a new way to improve the working temperature of magnetically topological devices.