Strain distribution and electronic states in stacked InAs/GaAs quantum dots with dot spacing 0– 6 nm

We have calculated the strain distribution and electronic structures in stacked InAs/GaAs quantum dots (QDs) with the dot spacing 6– 0 nm . We used the elastic continuum theory for the strain distribution, and the 8-band k · p theory for the electronic structures. For the triply stacked QDs, the light-hole (LH) component of the hole ground state increases with decreasing the dot spacing. The LH component in the columnar QD (dot spacing 0 nm ) reaches 21.1% which is 4.8 times larger than that in the single QD due to the reduction of the biaxial strain. Further increase of the LH component (up to 28.6%) is obtained in the fivefold-stacked columnar QD. This result suggests a possibility of increase in the TM-mode transition in the columnar QDs.