and their collective character was established [@Teran2003]. A very large Knight shift was observed in the 10-nm CdMnTe QWs ($x_{\text{Mn}}\sim0.2\%$ and $\sim0.3\%$) for a specific magnetic field strength at which the energies of free carrier and Mn spin excitations were almost equal. This ferromagnetic coupling between Mn spins and conduction electrons was theoretically described in Ref. [@Koenig2003]. The mean-field description of spin excitations developed in this work agreed quantitatively with the experimental data of Ref. [@Teran2003]. It was noted, however, that the long-range magnetic order in (Cd,Mn)Te QWs can be stabilized only by the spin-orbit coupling.

Resonant Raman scattering investigations also proved to be useful in a study of both collective and single-particle spin-flip excitations [@Jusserand2003; @Perez2006]. Careful measurements of angle-resolved magneto-Raman scattering on spin-flip waves in CdMnTe QWs [@Gomez2010] allowed clarification of the dispersion law of the damping rate $\eta$, which was found to be $\eta=\eta_0+\eta_2{\bf q}^2$ [@Hankiewicz2008], where [**q**]{} is the spin-wave in-plane momentum. The quadratic in [**q**]{} enhancement of the damping rate is described by a single-particle dynamics and occurs because of disorder and spin-Coulomb drag. Moreover, it was found that SO coupling affects spin waves in DMS QWs reconstructing them to chiral spin waves, which are 