Room-temperature optical manipulation of nuclear spin polarization in GaAsN

The effect of hyperfine interaction on the room-temperature defect-enabled spin filtering effect in GaAsN alloys is experimentally investigated and theoretically interpreted through a master equation approach based on the hyperfine and Zeeman interaction between electron and nuclear spin of the Ga-i(2+) interstitial spin filtering defect. We show that the nuclear spin polarization of the gallium defect can be tuned through the optically induced spin polarization of conduction band electrons.