Fe/Tb multilayer ferromagnets for local semiconductor spin control

We investigated a hybrid structure consisting of microstructured Fe/Tb multilayer ferromagnets (FMs) and a ZnCdMnSe dilute magnetic semiconductor quantum well (DMS QW) by means of superconducting quantum interference device (SQUID) magnetometry and micro-photoluminescence (µPL) spectroscopy. The Fe/Tb multilayers show a strong perpendicular magnetic anisotropy (PMA) with a temperature dependent coercive field Hc reaching values of 2.5 T /μ0 at 4 K. The out-of-plane magnetic fringe field stemming from the Fe/Tb microstructures induces a locally varying magnetization in the underlying DMS QW, which polarizes the spins of optically excited charge carriers in the DMS. We demonstrate that the coupling between these magnetic systems enables us to control the local carrier spin polarization in the DMS via the magnetization of microscale Fe/Tb ferromagnetic wires. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)