Effects of uniaxial stress on the electronic and optical properties of GaAs-${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As quantum wells

The electronic and optical-absorption properties of uniaxially stressed GaAs-${\mathrm{Al}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As quantum wells are studied with the use of multiband effective-mass theory. In bulk GaAs compressive uniaxial stress along [001] lifts the zone-center degeneracy of the heavy- and light-hole states with the heavy hole having lowered energy. In quantum wells strain-induced splitting substantially modifies the subband structure and optical absorption when the strain-induced splitting is comparable to the splitting between the first heavy hole and the first light hole due to the quantum size effect.