Anisotropy of electronic wave functions in self-aligned InAs dots on GaAs(001) studied by magnetic-field-dependent photoluminescence spectroscopy

Self-aligned InAs quantum dots (QD's) on top of [001]-oriented mesa stripes have been investigated by polarization and magnetic-field-dependent photol uminescence (PL) spectroscopy. The improved uniformity of the self-aligned dots grown by selective area epitaxy is confirmed by the relatively small l inewidth of the QD emission. At zero magnetic field, the PL signal of the Q D's reveals a remarkably large anisotropy with regard to the polarization d irections parallel and perpendicular to the mesa stripes. As a function of a magnetic field applied perpendicular to the growth surface, it displays a pronounced minimum at about 10 T. The initial decrease between 0 and 10 T verifies the controlled electronic coupling in a single row of QD's. The in crease beyond 10 T indicates experimental evidence for the inhomogeneous di stribution of the strain anisotropy inside QD's.