Heating of the spin system by nonequilibrium phonons in semimagnetic (Cd,Mn,Mg)Te quantum wells

We study the heating of the spin system of magnetic ions induced by ballist ic acoustic nonequilibrium phonons in (Cd, Mn, Mg)Te-based semimagnetic qua ntum wells using exciton luminescence technique. We find that the temperatu re of the spin system in the presence of nonequilibrium phonons decreases w ith the increase of magnetic field. In the analysis, we use the well-known fact that phonon losses at the solid/liquid helium boundary increase with t he increase of phonon energy. The results lead us to the conclusion that th e spin-heating effect is induced by phonons with energies resonant to the Z eeman splitting of spin sublevels of Mn ions. We propose a type of the subt erahertz phonon spectrometer that may be used for investigation of semicond uctor nanostructures. [S0163-1829(99)04831-6].