Piezomodulated reflectivity spectra of GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As single-parabolic-quantum-well heterostructures

Signatures associated with electronic states confined in a parabolic quantum well in a GaAs/${\mathrm{Al}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As heterostructure have been observed in its piezomodulated reflectivity spectrum. The spectra also exhibit electronic transitions with states confined to the spin-orbit-split valence band as the initial states. A comparison of the relative intensity of 11H and 11L signatures in the piezomodulated and those in the photomodulated reflectivity spectrum emphasizes the contribution of the strain dependence of the energies of the confined states.