Photo-enhanced Magnetoresistance Effect in GaAs with Nanoscale Magnetic Clusters

Enhanced positive magnetoresistance effect under light illumination has been observed in GaAs containing nanoscale magnetic clusters. The ferromagnetic clusters were embedded into GaAs by using Mn ion implantation and rapid thermal annealing Positive magnetoresistance in these structures has been observed and attributed to the scattering of charge carriers by the nanomagnet-dipole field. The enhancement of positive magnetoresistance under light illumination is due to a higher mobility of photoexcited electrons in comparison with the mobility of holes in p-type GaAs prepared by Mn ion implantation.