family of intrinsic magnetic topological insulators

The Mn(Bi,Sb)₂Te₄ family of intrinsic magnetic topological insulators has been predicted to be an ideal platform to realize a high temperature quantum anomalous Hall state, an axion insulating state, as well as a variety of other non-trivial band topologies. The strong coupling between the magnetic ordering in these compounds and the details of their band structure makes understanding their magnetic structure and its evolution with chemistry and magnetic field critical for understanding these exotic states. Our prior work has demonstrated that the field driven spin canting in MnBi₂Te₄ drives the measured intrinsic anomalous Hall effect in that compound but there are many questions to be addressed about the details of the evolution of the magnetic phase diagram in this system as the Bi atoms are replaced with Sb [1]. Prior magnetometry and magnetotransport shows a clear bulk magnetic behavior change with increased Sb content, but the microscopic details of this evolution are unclear [2]. We will present structural and magnetic neutron scattering measurements and other magnetic characterization of the Mn(Bi,Sb)₂Te₄ family of compounds to clarify this evolution.

[1] S. H. Lee et al., Phys. Rev. Research 1, 012011(R)
[2] J.-Q. Yan et al., arXiv:1905.00400 (2019).