Observation of a large spin-orbit interaction in photoexcited InxGa1-xAs/InyAl1-yAs heterostructures

Abstract

Far-infrared magneto-optical absorption measurements of photoexcited InGaAs/InAlAs heterostructures are carried out. The resonance peak positions of cyclotron resonance due to spin-up and -down electrons can be determined from modulated absorption signals quantitatively. The photopulse excitation by band gap light changes the resonance positions. The amplitude of the spin splitting is found to depend on the excitation intensity and delay time. The change in the spin splitting energy is dominated by the modulation of confinement potential by photoexcitation.