Reflectance spectroscopy on GaAs-Ga0.5Al0.5As single quantum wells under in-plane uniaxial stress at liquid-helium temperature

Reflectance spectroscopy is performed at 2 K on GaAs-${\mathrm{Ga}}_{0.5}$ ${\mathrm{Al}}_{0.5}$As quantum wells by molecular-beam epitaxy, for different widths of the GaAs confining layer and when uniaxial stress is applied perpendicularly to the growth axis. The modifications of the electronic states produced by the stress are experimentally determined via changes of the reflectance-energy characteristics of light-hole excitons and heavy-hole excitons and theoretically accounted for by calculations in the framework of the envelope-function formalism.