High resolution spectroscopy of self-assembled single GaAs/AlGaAs quantum dots

In this contribution we report the results of polarization resolved, high resolution photoluminescence spectroscopy of single lattice-matched, GaAs/Al0:3Ga0:7As quantum dots. The investigated samples are self assembled, strain free nanocrystals grown by Modifed Droplet Epitaxy technique. The lack of strain reflects in a nominal lack of piezoelectric field making such nanostructures potentially highly symmetric and suitable systems as polarization entangled photon sources. The high resolution, polarization resolved photoluminescence from isolated emitters present a clear linearlypolarized fine spectral splitting between the neutral exciton and biexciton lines while charged complexes are completely degenerate. By measuring the fine structure splitting and the line broadening of the excitonic photoluminescence we get new insights on the overlap of the opposite polarized lines (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)