Exchange coupling and polarization relaxation in self-assembled quantum dots

We consider the spin-coupling for one electron–hole pair bound in single self-assembled quantum dots. The long-range exchange coupling leads to a vanishing spin splitting of the ground interband transition in cylindrical dots. We evaluate the spin-splitting for different electron–hole levels of non-cylindrical structures. Both the dot shape anisotropy and an in-plane perturbing field are considered. The role of a fluctuating environment on the polarization of the bound dot luminescence is also discussed.