We report phase difference measurements at 50 and 30 mev from the excitonic peak of a GaAs/AlGaAs multiquantum-well structure. We find pronounced dispersion of the quadratic effect; in contrast, we see no indication of dispersion in the linear effect even this close to the bandgap.
Camille Sophie Brès, Anton Stroganov, Boris Zabelich, Edgars Nitiss
Camille Sophie Brès, Svyatoslav Kharitonov, Adrien Billat