Strong anisotropy of the photoluminescence linewidth in biaxially strained Zn1−x−yCdyMnxSe

The linewidth of the quasi-free exciton of biaxially strained Zn1−x−yCdyMnxSe varies strongly with increasing magnetic field. The dependences on magnetic field obtained in a Voigt geometry (B⊥k propagation vector of the detected light and growth direction z⊥B) and a Faraday geometry (B∥k and z∥B) differ significantly. The linewidth dependences can be explained using a static model based on cation statistics within a characteristic (excitonic) volume and taking into account heavy- and light-hole mixing. It is shown that the potential landscape changes on a microscopic as well as on a mesoscopic scale.