ATOMICALLY PRECISE GAAS ALGAAS QUANTUM DOTS FABRICATED BY TWOFOLD CLEAVED EDGE OVERGROWTH/

The formation of a 7 x 7 x 7 nm(3) size GaAs quantum dot (QD) at the i ntersection of three quantum wells is demonstrated for the first time. Intense radiative recombination between zero-dimensional states in th e QDs is clearly identified by microscopic photoluminescence (mu PL). In contrast to the inhomogeneously broadened quantum well and quantum wire signals originating from the complex twofold cleaved edge overgro wth structure, the strongly spatially localized QD response is charact erized by spectrally sharp lines in mu PL excitation spectra with a li newidth below 70 mu eV.