Conduction electrons bound to magneto-acceptors andmagneto-donors in GaAs/GaAlAs quantum wells

摘要

New discrete states of conduction electrons bound to ionized acceptors inheterostructures are observed for the first time in intraband magneto-optical experimentson GaAs/Ga0.67Al0.33As quantum wells δ-doped in the well with Be acceptors. Theconduction electrons are bound to ionized acceptors by a joint effect of the well and anexternal magnetic field. The energies of the states, which occur above the Landau levelsof free conduction electrons, are successfully described using the single magneto-acceptorwavefunctions. Similar experiments are carried out on GaAs/Ga0.67Al0.33 quantum wellsδ-doped in the well with Si donors. The rich spectrum of magneto-donors is comparedexperimentally and theoretically with that of magneto-acceptors. On samples doped with Beacceptors we observe for the first time two magneto-optical peaks related to acceptor potentialfluctuations.