Atomistic simulation of InxGa1−xAs/GaAs quantum dots with nonuniform composition

An atomistic model of an InxGa1−xAs/GaAs quantum dot with nonuniform composition is investigated. An empirical interatomic potential, the Tersoff potential, is used to obtain dynamic relaxation through energy minimisation. Bond deformations are analysed in order to predict the components of the strain tensor with resolution on the atomic scale, revealing the nature of the lattice distortion in both the dot pyramid and the capping layer. The piezoelectric charges are then computed directly from the off diagonal components of the strain, revealing a wider distribution of the dipoles compared to those previously reported by other groups.