Abstract
We compare the asymmetry-induced exchange splitting of the bright-exciton ground-state doublet in self-assembled quantum dots, determined by Faraday rotation, with its homogeneous linewidth , obtained from the radiative decay in time-resolved photoluminescence. Postgrowth thermal annealing of the dot structures leads to a considerable increase of the homogeneous linewidth, while a strong reduction of the exchange splitting is simultaneously observed. The annealing can be tailored such that and become comparable, whereupon the carriers are still well confined. This opens the possibility to observe polarization entangled photon pairs through the biexciton decay cascade.
- Received 18 October 2005
DOI:https://doi.org/10.1103/PhysRevB.73.045323
©2006 American Physical Society