This work uses atomistic modeling to explain why highly asymmetric InAs/InP quantum dots can nevertheless exhibit very small fine-structure splitting. It shows that realistic elongation, faceting, and atomistic symmetry can reshape the bright-exciton doublet in ways that differ from simple continuum expectations.
Keywords: InAs/InP, fine-structure splitting
Main result: atomistic symmetry and realistic geometry strongly control excitonic splitting and polarization. In particular, shape elongation of quantum dots can not only decrease, but even reverse, the splitting of the two lowest optically active excitonic states.