Semiconductor nanostructures engineering: Pyramidal quantum dots

Pyramidal quantum dots (QDs) grown in inverted recesses have demonstrated over the years an extraordinary uniformity, high spectral purity and strong design versatility. We discuss recent results, also in view of the Stranski–Krastanow competition and give evidence for strong perspectives in quantum information applications for this system. We examine the possibility of generating entangled and indistinguishable photons, together with the need for the implementation of a, regrettably still missing, strategy for electrical control.

► Pyramidal quantum dots grown in inverted recesses have demonstrated over the years an extraordinary uniformity.
► Also record linewidths where obtained for site controlled quantum dots.
► A special growth mechanism (capillarity plus growth/decomposition rate anisotropies) is what allows this.
► Nitrogen incorporation delivers high quantum dot symmetry.
► Reliable sources of non-classical light are a strong perspective.