Kinetic exchange between the conduction band electrons and magnetic ions in quantum-confined structures

We provide an experimental evidence and a theoretical substantiation for a strong reduction of the s-d exchange interaction between electrons and Mn-i on spins with increasing degree of the confinement in nanostructures of dil uted magnetic semiconductors. By spin-flip Raman scattering a strong (up to 25%) reduction of the exchange parameter is observed in (Cd,Mn)Te/(Cd,Mn, Mg)Te quantum well structures. As a responsible mechanism we suggest switch ing-on of the kinetic exchange for the conduction electrons with finite k v ectors. Quantitative agreement between experimental data and calculations i s achieved.