Time-resolved photoluminescence measurements show that the decay time for charged excitons in a GaAs two-dimensional electron gas increases by an order of magnitude at high magnetic fields. Unlike neutral excitons, the charged exciton center-of-mass is spatially confined in a ``magnetically-adjustable quantum dot'' by the cyclotron orbit and the quantum well. The inhibited recombination is explained by a reduced phase coherence volume of the magnetically-confined charged excitons.
@article{arxiv.cond-mat/9810109,
title = {Inhibited Recombination of Charged Magnetoexcitons},
author = {H. Okamura and D. Heiman and M. Sundaram and A. C. Gossard},
journal= {arXiv preprint arXiv:cond-mat/9810109},
year = {2009}
}