Conduction band spectra in self-assembled InAs/GaAs dots: A comparison of effective mass and an eight-band approach

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Abstract
Strained epitaxy has been shown to produce high quality InAs/GaAs quantum dot structures by single step epitaxy. While effective mass-based approaches have been used for quantum structures, the nature of the strain and quantum confinement in self-assembled dots is such that this is not a good approximation. In this letter, we use an eight-band k⋅p formalism to find the electronic spectra in InAs/GaAs dots. The eight-band model shows that, in agreement with experiments, there are indeed several bound states in the conduction band well. Our results show that the simpler effective mass approaches cannot be used to quantitatively examine the physics of intersubband devices based on self-assembled quantum dots. Intersubband optical matrix elements and Coulomb blockade energy are also calculated in this letter.