Coulomb correlated multi-particle states of weakly confining GaAs quantum dots

Abstract

We compute the electronic and emission properties of Coulomb-correlated multi-particle states (X${}^0$, X${}^{\pm }$, XX) in weakly confining GaAs/AlGaAs quantum dots using an 8-band $\mathbf{k}\cdot \mathbf{p}$ model coupled to continuum elasticity and configuration interaction (CI). We evaluate polarization-resolved oscillator strengths and radiative rates both in the dipole approximation (DA) and in a quasi-electrostatic beyond-dipole (BDA) longitudinal formulation implemented via a Poisson reformulation exactly equivalent to the dyadic Green-tensor kernel. For the dots studied, BDA yields lifetimes in quantitative agreement with experiment, e.g., $\ddot{I}{„}^X=0.279\mathrm{ns}$ vs $0.267\mathrm{ns}$ (exp.) and $\ddot{I}{„}^{XX}=0.101\mathrm{ns}$ vs $0.115\mathrm{ns}$ (exp.). The framework also reproduces electric-field tuning of the multi-particle electronic structure and emission-including the indistinguishability inferred from $P=\ddot{I}{„}^X/(\ddot{I}{„}^X+\ddot{I}{„}^{XX})$-and we assess sensitivity to CI-basis size and to electron-electron and hole-hole exchange.