Photo-enhanced magnetoresistance effect in GaAs with nanoscale magnetic clusters

Enhanced positive magnetoresistance effect under light illumination has bee n observed in GaAs containing nanoscale magnetic clusters. The ferromagneti c clusters were embedded into GaAs by using Mn ion implantation and rapid t hermal annealing Positive magnetoresistance in these structures has been ob served and attributed to the scattering of charge carriers by the nanomagne t-dipole field. The enhancement of positive magnetoresistance under light i llumination is due to a higher mobility of photoexcited electrons in compar ison with the mobility of holes in p-type GaAs prepared by Mn ion implantat ion.