CONTROL OF QUASI-BOUND STATES BY ELECTRON BRAGG MIRRORS IN GAAS AL0.3GA0.7AS QUANTUM-WELLS/

Electron Bragg mirrors grown on both sides of identical quantum wells were used for confining above-barrier states at different energies, By varying the thickness of the electron mirrors, a confined above-barri er state (a quasi-bound state) changed by over 110 meV in a 40 Angstro m wide GaAs/Al0.3Ga0.7As quantum well. Formation of quasi-bound states due to the electron Bragg mirrors was theoretically investigated usin g the envelope function approximation and semi-infinite superlattice l imit of the electron mirror layers. Theoretical calculations for absor ption spectra involving quasi-bound states are compared with experimen tal results. (C) 1996 American Institute of Physics.