Internal transitions of negatively charged magnetoexcitons and many body effects in a two-dimensional electron gas

A study of internal transitions of quasi-two-dimensional, negatively charged magnetoexcitons (X^-) and their evolution with excess electron density, in GaAs/AlGaAs quantum wells, was presented. The optically detected resonance spectra were dominated by bound-to-continuum bands, in dilute electron limit, in contrast to negatively charged donor system due to magnetic translational invariance. Magnetoplasmons bound to a mobile valence band hole was used to explain the blueshifted transitions.