Time evolution of entanglement of N quantum dots is analyzed within the spin-1/2 van der Waals (or Lipkin-Meshkov-Glick) XY model. It is shown that, for a single dot initially excited and disentangled from the remaining unexcited dots, the maximum bipartite entanglement can be obtained in the systems of N=2,...,6 dots only.
@article{arxiv.quant-ph/0109144,
title = {Maximum entanglement of quantum-dot systems with single excitation in the spin van der Waals model},
author = {A. Miranowicz and S. K. Ozdemir and M. Koashi and N. Imoto and Y. Hirayama},
journal= {arXiv preprint arXiv:quant-ph/0109144},
year = {2007}
}