INTERBAND OPTICAL-TRANSITIONS IN SEMICONDUCTOR QUANTUM WIRES - SELECTION-RULES AND ABSORPTION-SPECTRA

The nonparabolic valence subband dispersions of GaAs quantum wires are calculated starting from the Luttinger-Kohn Hamiltonian. The electron hole matrix elements are derived for the different photon polarizations with respect to the wire orientation and are studies as a function of the lateral confinement. It is shown that the confinement-induced mixing between heavy-hole (hh) and light-hole (lh) states is crucial for the anisotropy of interband transitions. We demonstrate how a polarization-dependent optical experiment can be used to measure the hh-lh mixing in the valence subband states and to identify the subbands that contribute to an observed transition.