Multi-exciton states and many-body correlations in quantum dots

Abstract

We theoretically study the optical emission spectra of multi-exciton states using a configuration interaction approach for a few excitons and a density functional calculation for several excitons in a single quantum dot. Considering InP quantum dots as an example, we show that the biexciton binding energy is determined by a delicate balance of contributions from several configurations. We discuss how Coulomb correlations and the spin fine-structure of multi-excitonic states clearly manifest in the emission spectrum of highly excited quantum dots. We also predict a new kind of configuration crossing transitions that lead to weak emission lines several tens of meV below the exciton ground state.