Spin-split cyclotron resonance and spatial distribution of interacting electrons

The interaction coupling of cyclotron transitions with different spin orientation was investigated as a function of density for electron inversion layers in GaAs in the magnetic quantum limit. The spatial electron distribution strongly influences the coupling of the electrical dipole transitions, resulting in deviations from the interaction strength for ideally two-dimensional electrons. At the higher densities the coupling is essentially reduced due to the finite thickness of the inversion layer, whereas at sufficiently low densities the coupling reflects the influence of disorder.