EXCITONIC NONLINEAR-OPTICAL PROCESSES IN GAAS QUANTUM-WELL WIRES

In a recent calculation, we obtained exciton and biexciton binding energies and wave functions for a rectangular quantum wire in order to determine its third-order nonlinear optical susceptibility χ(3). Using a variational calculation involving two parameters-exciton radius and exciton-exciton separation within the biexciton-we computed the binding energies of the exciton and biexciton. In the present paper, we have included a third parameter to allow for the variation of exciton radius within the biexciton. As the result of this added variational freedom, the biexciton binding energies changed by 7-10 % and the magnitudes of all variational parameters and of χ(3) changed by approximately 20% for wire dimensions between 25×25 and 300×3002. © 1995 The American Physical Society.