Resonant optical alignment and orientation ofMn2+spins in CdMnTe crystals

Abstract

We report on spin orientation and alignment of ${\mathrm{Mn}}^{2+}$ ions in (Cd,Mn)Te diluted magnetic semiconductor crystals using resonant intracenter excitation with circular- and linear-polarized light. The resulting polarized emission of the magnetic ions is observed at low temperatures when the spin relaxation time of the ${\mathrm{Mn}}^{2+}$ ions is in the order of $1\phantom{\rule{0.28em}{0ex}}\mathrm{ms}$, which considerably exceeds the photoluminescence decay time of $23\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}$. We demonstrate that the experimental data on optical orientation and alignment of ${\mathrm{Mn}}^{2+}$ ions can be explained using a phenomenological model that is based on the approximation of isolated centers.