Asymmetric spin transitions of nonthermalized Mn2 + ions in (Zn,Mn)Se-based quantum wells

In Zn_{1 -x}Mn_xSe /(Zn,Be)Se quantum wells with x <0.035 , nonthermalized Mn^{2 +} ions demonstrate in spin-flip scattering spectra multiple Stokes and anti-Stokes transitions whose absolute energies deviate by up to 20% from each other. This asymmetry is tuned significantly by the optical power density, magnetic field direction, and Mn ion concentration. The nonequidistant Mn^{2 +} spin transitions are modeled by the Zeeman splitting and quadrupolar crystal-field components taking values of up to 7 GHz. We suggest that nonequilibrium carriers dynamically polarize the Mn-ion spins so that they occupy levels with positive and negative spin projection numbers giving rise to asymmetric spin transitions.