Optical transitions in quantum wires with strain-induced lateral confinement

Nanometer-scale quantum wires have been directly produced using an epitaxial-growth technique. Modulation of the in-plane lattice constant of a GaAs/GaAlAs quantum well, grown over an InGaAs/GaAs strained-layer superlattice, laterally confines the carriers to one dimension. These novel structures are studied by luminescence and luminescence-excitation spectroscopies and by transmission electron microscopy. Large energy shifts and polarization anisotropy are observed. The results compare very well with a theoretical model based on the effective-mass approximation and elastic and phenomenological deformation-potential theories.