Fig. 1. Two vertically coupled InAs HQDs with WLs embedded in a GaAs barrier.

Fig. 2. Electron ground, first, and second excited state energy eigenvalues versus HQD (a) base radius and (b) height for TVCHQDs/WLs.

Fig. 3. Interband transition energy versus HQD (a) base radius and (b) height for TVCHQDs/WLs.

Fig. 4. Linear (a) absorption and (b) dispersion, and nonlinear (c) absorption and (d) dispersion of the probe pulse as a function of the probe frequency ωp. The solid and dot-dashed lines correspond to single HQD/WL and TVCHQDs/WLs, respectively.