Magneto-optical spin spectroscopy in hybrid ferromagnetic semiconductor heterostructures

We report on magneto-optical measurements of diluted magnetic semiconductor quantum well structures in which an iron film is epitaxially grown and subsequently patterned on top of the heterostructure. The magnetic field due to the iron penetrates the quantum well near the edges of the patterned regions. Photoluminescence, Hanle effect, and time-resolved Faraday rotation measurements demonstrate that the films can be processed without significantly altering the electronic properties of the quantum well. The smallest length scale probed in these far-field optical measurements is of order 10 μm, so that no effects of the local magnetic fields at the film edges are observed for structures with 50-nm-thick ferromagnetic layers.