Effects of the Coulomb interaction on the optical spectra of quantum wires

We investigate theoretically excitonic effects on the optical properties of quantum-wire structures. The spatial nonlocal optical susceptibility is expressed in terms of electron-hole pair wave functions and energies. The corresponding two-particle equation is numericllay solved assuming a complete vertical confinement. The resulting exciton energies and the oscillator strengths are studied versus the wire confinement. The interplay of Coulomb attraction, center-of-mass quantization, and confinement of the internal motion is discussed. Very recent luminescence spectra for quantum-wire arrays fabricated by means of laser-induced cation interdiffusion, which show a variety of narrow exciton lines, can be interpreted.