Fluctuations of the intersubband splitting energy and the potential well shape of two-dimensional electrons in the quantum Hall effect regime

Recombination radiation and inelastic light scattering spectra of 2D electrons are studied simultaneously in structures with a single GaAs quantum well in the quantum Hall effect regime. It is found that the intensity of intersubband inelastic light scattering (the SDE mode) at the filling factor ν = 2 exhibits fluctuations in phase with fluctuations of the photoluminescence intensity of 2D electrons of the ground subband. It is shown that, simultaneously with fluctuations of the scattered light and recombination radiation intensities, the spectral positions of these lines change stepwise by 0.3–0.5 meV. The jumps found in the spectral positions of lines are observed only in narrow intervals of magnetic fields corresponding to the quantum Hall effect and are presumably associated with zero-point fluctuations (Casimir-Lifshits force).