Morphological and optical anisotropy of quantum dots probed by magneto-tunneling and photoluminescence-polarization spectroscopy

We use magneto-tunneling spectroscopy to investigate the form of the wave function of the confined electron states in self-assembled InAs quantum dots grown on (1 0 0)- and (3 1 1)B-oriented GaAs substrates. For both orientations, the electron wave function has a biaxial symmetry in the growth plane and is elongated along the principal crystallographic direction. We investigate the influence of the anisotropy of the electron wave function on the polarization properties of the dot photoluminescence and find that the dot optical anisotropy is mainly caused by anisotropic strain.