Excitons in InP quantum dots

The excitonic spectrum of InP quantum dots is investigated using an atomistic pseudopotential approach for the single-particle problem and a state-dependent screened Coulomb interaction for the many-body problem. Our calculations show a different energy distribution of single-particle states relative to the commonly used $\mathbf{k}\mathbf{\cdot }\mathbf{p}$ theory as well as significant parity mixing in the envelope functions, forbidden in $6\times 6$ $\mathbf{k}\cdot \mathbf{p}$. The calculated excitonic spectrum, including seven excitons, explains well the recent experimental measurements.