Overhauser effect and anisotropy of electron spin g-factor in GaAs / AlGaAs quantum wells

To investigate the dependence of electron g-factor on magnetic field in GaAs / AlGaAs quantum wells time-resolved photoluminescence measurements under a high magnetic field in different experimental configuration, the magnetic field perpendicular (g up tack ) and parallel (g II) to the quantum confinement direction, has been studied. When the angle between the magnetic field and the confinement direction is 45°, the precession frequency varies depending on polarity of magnetic field and the circular polarization type of excitation light (sigma+ or sigma-). We found that these dependences of the precession frequency exhibit main features of Overhauser effect with an effective magnetic field of 0.5 T that nuclear spins react back on electron spin precession and the g-factor value is not affected by the effective magnetic field. The g+ and gii values agree well with the results of four-band k • p perturbation calculations.