SUBBAND SPECTROSCOPY OF SINGLE AND COUPLED GAAS QUANTUM-WELLS

Electronic excitations in the conduction band of a single-side-doped GaAs quantum well with a thin AlAs barrier in its center (coupled, double quantum well) and of a well of equal width and growth parameters without barrier (single quantum well) are examined by far-infrared Fourier-transform spectroscopy. We measure intersubband energies, cyclotron masses in perpendicular magnetic fields, and dipole matrix elements in tilted magnetic fields. The experimental results are compared for the two samples and are quantitatively reproduced by a self-consistent description that takes into account the nonparabolic band structure of the semiconductors. © 1990 The American Physical Society.