Electronic structures of (In,Ga)As/GaAs quantum dot molecules made of dots with dissimilar sizes

Abstract

Using single-particle pseudopotential and many-particle configuration interaction methods, we compare various physical quantities of (In,Ga)As/GaAs quantum dot molecules (QDMs) made of dissimilar dots (heteropolar QDMs) with QDMs made of identical dots (homopolar QDMs). The calculations show that the electronic structures of hetero-QDMs and homo-QDMs differ significantly at large inter-dot distance. In particular (i) Unlike those of homo-QDMs, the single-particle molecular orbitals of hetero-QDMs convert to dot localized orbitals at large inter-dot distance. (ii) Consequently, in a hetero-QMD the bonding-antibonding splitting of molecular orbitals at large inter-dot distance is significantly larger than the electron hopping energy whereas for homo-QDM, the bonding-antibonding splitting is very similar to the hopping energy. (iii) The asymmetry of the QDM increases significantly the double occupation for the two-electron ground states, and therefore affects the degree of entanglement of the two electrons.

11 pages, 11 figures

References in corpus (7)

• Manipulation of a single charge in a double quantum dot
• General criterion for the entanglement of two indistinguishable particles
• Singlet-triplet spin blockade and charge sensing in a few-electron double quantum dot
• Theory of excitonic spectra and entanglement engineering in dot molecules
• Singlet-triplet splitting, correlation and entanglement of two electrons in quantum dot molecules
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• Asymmetry in self-assembled quantum dot-molecules made of identical InAs/GaAs quantum dots

Cited by in corpus (2)

• Effect of confinement potential geometry on entanglement in quantum dot-based nanostructures
• Impurity Effects in Two-Electron Coupled Quantum Dots: Entanglement Modulation