Optical probing of the spin state of a single magnetic impurity in a self-assembled quantum dot

Optical spectra of a self-organized quantum dot with a single magnetic impurity are studied. The quantum dot potential and exchange interactions result in an additional fine structure of an exciton localized in a quantum dot with a magnetic impurity. In contrast to the undoped quantum dots, the ground state excitons in the quantum dot with a magnetic impurity are bright. It is also shown that an initial spin state of the Mn atom leaves a unique pattern in the optical response. This suggests the possibility to read out optically the spin polarization of a single Mn atom.