Electron Spin-Splitting in Photoexcited INXGA1-X AS/INYAL1-Y as Heterostructures

Far-infrared magneto-optical absorption measurements of InGaAs/InAlAs heterostructures are carried out for investigation of the zero-field spin-splitting of electrons. The resonance positions of cyclotron resonance due to spin-up and -down electrons are identified in modulation absorption signals under photoexcitation and the splitting energy can be estimated by the positions. The photo pulse excitation by band gap light changes the resonance positions. Peak splitting is found to depend on the excitation intensity and delay time. The spin-splitting energy can be tuned by the band gap illumination without any gate structures.