Microluminescence from Cd1-xMnxTe magnetic quantum dots containing only a few Mn ions

Self-assembled magnetic CdxMn1-xTe quantum dots (QDs) embedded in nonmagnetic Zn0.6Cd0.4Te were grown by molecular beam epitaxy. We achieved a large degree of dilution of Mn ions inside the QDs, x(Mn)=0.003, which allowed us to study single QDs containing only few Mn ions. The insight into properties of these structures was obtained by performing measurements of photoluminescence in an external magnetic field with a high spatial resolution by using immersion reflection objective. Approximate number of Mn ions inside dots and the size of the dots were found by comparison of the magnetic field evolution of the corresponding photoluminescence lines with calculations in terms of a muffin tin model developed originally to describe bound magnetic polarons.