We show that qubits coupled sequentially to a mesoscopic static completely mixed spin bath via the Heisenberg interaction can become highly entangled. Straightforward protocols for the generation of multipartite entangled (Greenberger-Horne-Zeilinger-)states are presented. We show the feasibility of an experimental realization in a quantum dot by the hyperfine interaction of an electron with the nuclear spins.
@article{arxiv.0710.4120,
title = {Entanglement generation via a completely mixed nuclear spin bath},
author = {H. Christ and J. I. Cirac and G. Giedke},
journal= {arXiv preprint arXiv:0710.4120},
year = {2008}
}