  We have investigated spin relaxation times in CdTe quantum dots doped with a
single Mn atom, a prototype of a system where the interaction between a single
charge carrier and a single spin takes place. A theoretical model that was used
includes the electron-Mn spin exchange interaction responsible for mixing of
the states of different spin in the basic Hamiltonian and electron-phonon
interaction as a perturbation responsible for transitions between the states.
It was found that the dominant electron-phonon interaction mechanism
responsible for spin relaxation is the interaction with acoustic phonons
through deformation potential. Electron and Mn spin relaxation times at room
temperature take values in the range from microseconds at a magnetic field of
0.5 T down to nanoseconds at a magnetic field of 10 T and become three orders
of magnitude larger at cryogenic temperatures. It was found that electron
spin-orbit interaction has a negligible effect on spin relaxation times, while
the changes in the position of the Mn atom within the dot and in the dot
dimensions can change the spin relaxation times by up to one order of
magnitude.
