Coulomb-induced suppression of band-edge singularities in the optical spectra of realistic quantum-wire structures

The linear and nonlinear optical properties of realistic quantum wires are studied through a theoretical approach based on a set of generalized semiconductor Bloch equations. Our scheme allows a full three-dimensional multisubband description of electron-hole correlation for any confinement profile, thus permitting a direct comparison with experiments for available quantum-wire structures. Our results show that electron-hole Coulomb correlation removes the one-dimensional band-edge singularities from the absorption spectra, whose shape is heavily modified with respect to the ideal free-carrier single-subband case over the whole density range.