The electronic structure of a single self-assembled InAs quantum dot was investigated with the precise manipulation of the energy levels of the dots. Elastic single-electron tunneling was probed through a pair of weakly coupled quantum dots. A double layer of InAs dots embedded in a sub-micron size pillar was employed and a single vertical pair of dots was isolated by depleting the structure with a side gate. The nonlinear threshold voltage behavior provided electronic addition energies in the region below pinch-off voltage, which was similar to Coulomb blockade oscillation. Fock-Darwin spectra of the s and p shells was provided by the evolution of the shell addition spectrum with magnetic field.
ASJC Scopus subject areas