Exotic magnetic properties of diluted magnetic binary chalcogenides

Using first-principles Green function approach we studied electronic and magnetic properties of diluted magnetic binary chalcogenides A$_2$B$_3$, doped with transition metals substituing the A element. The electronic structure of the impurities in the chalcogenides is mainly featured by the crystal field splitting. We found that two main mechanisms are responsible for long-range magnetic order in these materials: hole mediated magnetism within the layer of A atoms and indirect interaction between magnetic moments via a B atom. We also estimated Curie temperature of these systems, which was found in good agreement with the available experimental data. Our results shed light on the understanding of magnetic interaction and control in toplogical insulators.