Magnetotransport, magneto-optical, and electronic subband studies in InxGa1-xAs/InyAl1-xAs modulation-doped strained double quantum wells

Abstract

Magnetotransport and magneto-optical measurements on InxGa1-xAs/InyAl1-yAs modulation-doped strained double quantum wells with a 100 Angstrom In0.8Ga0.2As well and a 100 Angstrom In0.53Ga0.47As quantum wells separated by a 35 Angstrom In0.25Ga0.75As potential barrier were carried out to investigate the electrical and the optical properties of the electron gas in the quantum wells. The Shubnikov-de Haas measurements at 1.5 K demonstrated clearly the occupation of three subbands in the quantum wells by a two-dimensional electron gas. The electron effective masses determined from the slopes of the cyclotron resonance peak energies as a function of the magnetic field were 0.06171 and 0.05228m(e). The electronic subband energies, the subband energy wavefunctions, and the Fermi energy in the quantum wells were self-consistently calculated a transfer matrix method taking into account the exchange-correlation effect, the strain effect, and the nonparabolicity effect, and the results of the cyclotron resonance measurements qualitatively show the nonparabolicity effect in the strained double quantum well. (C) 1997 American Institute of Physics. [S0021-8979(97)06620-6].