Influence of valence band spin–orbit coupling on the entanglement of excitons in coupled quantum dots

We study the effect of valence band spin–orbit interaction on the exciton entanglement in vertically stacked quantum dots, using a multi-band k·p theory for holes. It is shown that the spin–orbit interaction reduces the exciton entanglement, establishing an intrinsic upper limit. For usual InGaAs nanostructures, however, this effect is generally small and does not pose a challenge for current attempts for the development of quantum information.