Interband absorption in quantum wires. I. Zero-magnetic-field case

Abstract

We describe the theory of interband transitions in quasi-one-dimensional semiconductor structures. It is based on the effective-mass approximation and takes into account the mixing of the heavy-hole and the light-hole states in the valence band. The dipole matrix element for optical transitions between the valence-band and the conduction-band states is derived for different linear photon polarizations with respect to the wire orientation. The theory is applied to single wires and periodic arrays of coupled wires exhibiting spatially direct or indirect optical transitions. We also study the influence of sample imperfections by calculating the optical properties of a statistical ensemble of confinement potentials exhibiting random fluctuations.