Identification of a dominant mechanism for optical spin injection from a diluted magnetic semiconductor: Spin-conserving energy transfer via localized excitations

Abstract

We provide compelling experimental evidence for a spin-conserving energy-transfer process via localized excitations as being responsible for the observed optical spin injection in $\mathrm{Zn}\mathrm{Mn}\mathrm{Se}∕\mathrm{Zn}\mathrm{Cd}\mathrm{Se}$ quantum structures. We show that such a process is common and inherent to a diluted magnetic semiconductor because of strong potential fluctuations.