Narrow barriers and tailored confinement states in GaAs AlGaAs quantum wells

Abstract We have investigated the effect on the confinement subband energies of thin (two monolayers) AlAs barriers positioned at the centers of the GaAs layers in a GaAs/AlGaAs multiple-quantum-well structure. Interband as well as interconduction-subband transitions from two structures, one with, and the other without the thin AlAs barriers were studied by reflectance, photoluminescence and far-infrared magneto-transmission spectroscopies. The results are in good agreement with one-dimensional calculations, and are indicative of the high quality of the thin barriers.