Spin-dependent tunneling in semiconductor heterostructures with a magnetic layer

We present a theory that describes the appearance of circular polarization of the photoluminescence (PL) in ferromagnet-semiconductor hybrid heterostructures due to the spin-dependent tunneling of photoexcited carriers from a quantum well into a magnetic layer. The theory succeeds in explaining the experimental data on time-resolved PL for heterostructures consisting of an InGaAs-based quantum well (QW) and a spatially separated Mn delta layer. We show that the circular polarization of the PL originates from the dynamic spin polarization of electrons due to spin-dependent leakage from the QW onto the Mn donor states split by the exchange field of the ferromagnetic Mn d layer.