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 nanostruc-tures potentially highly symmetric and suitable systems as polarization entangled photon sources. The high resolution, polarization resolved photoluminescence from isolated emitters present a clear linearly-polarized fine spectral splitting between the neutral ex-citon and biexciton lines while charged complexes are completely degenerate. By measuring the fine structure splitting and the line broadening of the excitonic photo-luminescence we get new insights on the overlap of the opposite polarized lines.