Fabrication of an InGaAs spin filter by implantation of paramagnetic centers

We report on the selective creation of spin filtering regions in non-magnetic InGaAs layers by implantation of Ga ions by Focused Ion Beam. We demonstrate by photoluminescence spectroscopy that spin dependent recombination (SDR) ratios as high as 240% can be achieved in the implanted areas. The optimum implantation conditions for the most efficient SDR are determined by the systematic analysis of different ion doses spanning four orders of magnitude. The application of a weak external magnetic field leads to a sizable enhancement of the SDR ratio from the spin polarization of the nuclei surrounding the polarized implanted paramagnetic defects.