Efficient multipartite entanglement purification with the entanglement link from a subspace
Fu‐Guo Deng · Physical Review A · 2011
We present an efficient multipartite entanglement purification protocol (MEPP) for $N$-photon systems in a Greenberger-Horne-Zeilinger state with parity-check detectors. It contains two parts. One is the conventional MEPP with which the parties can obtain a high-fidelity $N$-photon ensemble directly, similar to the MEPP with controlled-not gates. The other is our recycling MEPP in which the entanglement link is used to produce some $N$-photon entangled systems from entangled ${N}^{\ensuremath{'}}$-photon subsystems ($2\ensuremath{\leqslant}{N}^{\ensuremath{'}}