Abstract
We investigate theoretically the electron spin states in disk-shaped HgTe topological insulator quantum dots (TIQDs) containing a single magnetic Mn²⁺ ion. We show that the energy spectrum and the electron density distribution of the topological edge states in HgTe TIQD can be modulated significantly by the position of the magnetic Mn²⁺ ion. The numerical results further demonstrate that the electric fields not only tune the spin splittings of edge states via the sp-d exchange interaction between the electron (hole) and the magnetic Mn²⁺ ion but also give rise to the bright-to-dark transitions and anti-crossing behaviors in the photoluminescence (PL) spectra. Such spin properties of HgTe TIQDs with single Mn²⁺ ion as illustrated in this work could offer a new platform for topological electro-optical devices.