The effect of band nonparabolicity on modeling few-electron ground states of charge-tunable InAs/GaAs quantum dot

Based on the current spin density functional theory and the nonparabolic effective mass approximation, a three-dimensional model is presented to study the few-electron system in InAs/GaAs quantum dot for which the electron spectra have been obtained from the capacitance–voltage (CV) measurements by Miller et al. [Phys. Rev. B 56 (1997) 6764]. The model is an extension of the single-electron model proposed by Filikhin et al. [Solid State Comm. 140 (2006) 483]. Our results can quantitatively well interpret the experimental CV data. It is shown that the energy differences between the parabolic and nonparabolic approximations are comparable with the exchange-correlation energies. Moreover, the nonparabolic effect is shown to be increasingly more significant than that of parabolic case in higher magnetic fields. It is also more pronounced for larger number of electrons.