Spin-flip Raman scattering in semi-magnetic quantum wells with in-plane anisotropy: Analysis of the intermediate states

Abstract

Spin-flip Raman scattering has been studied in $\mathrm{CdTe}/{\mathrm{Cd}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{Te}$ quantum well structures which have previously been demonstrated to possess a reduced symmetry, leading to a hole g tensor which is highly anisotropic in the plane. This unusual behavior has been exploited to investigate in detail the spin-flip Raman-scattering mechanisms. Distinct signals arising from localized excitons and from excitons bound to neutral donors are observed. These signals are found to vary in intensity depending on the angle between the crystal axes and the in-plane magnetic field. The intensities of the signals as a function of laser energy have also been determined. From these observations, a model involving the nature of the intermediate states in the scattering process has been developed which allows the determination of the components of hole g tensor. This model is further applied to explain the observed angular dependence of the spin-flip Raman scattering of the ${3d}^{5}$ electrons of the ${\mathrm{Mn}}^{2+}$ ions. In addition, the model predicts a combined scattering process involving both a ${\mathrm{Mn}}^{2+}$ electron and a donor-bound electron; this process is indeed observed.