  Epitaxial InAs/GaAs Quantum Dots (QDs) are widely used as highly efficient
and pure sources of single photons and entangled photon-pairs, however reliable
wafer-scale growth techniques have proved elusive. Growth of two-dimensional
Quantum Well (QW) thin-films can be achieved with atomic precision down to
below the de Broglie wavelength of electrons in the material, exposing the
quantum particle-in-a-box energy vs. thickness-squared relationship. However,
difficulties in controlling the exact moment of nanostructure nucleation
obscure this behaviour in epitaxial QD material, preventing a clear
understanding of their growth. In this work we demonstrate that QD nucleation
can be induced by directly modulating the crystal surface energy without
additional materials or equipment. This gains us quantitative measure of the QD
growth rate and enables predictive design of QD growth processes. We believe
this technique will be crucial to the realisation of uniform arrays of QDs
required for scalable quantum devices at the single-photon level.
