Binding energies and diamagnetic shifts for free excitons in symmetric coupled double quantum wells

A simple method for calculating the free-exciton binding energies in the fractional-dimensional-space model for single-quantum-well (SQW) structures has been extended to symmetric coupled double quantum wells (CDQW). We also apply these results to estimate the diamagnetic shift of the free excitons for both CDQW and SQW systems. Corresponding experimental photoluminescence data are obtained on CDQW and SQW samples grown by molecular-beam epitaxy. The calculated binding energies and diamagnetic shifts show good agreement with the experimental data.