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. (c) 2007 Elsevier B.V. All rights reserved.