The quantum entangled degrees of entangled states become smaller with the transmission distance increasing, how to keep the purity of quantum entangled states is the puzzle in quantum communication. In the paper, we have designed a new type entanglement degrees amplifier by one-dimensional photonic crystal, which is similar as the relay station of classical electromagnetic communication. We find when the entangled states of two-photon and three-photon pass through photonic crystal, their entanglement degrees can be magnified, which make the entanglement states can be long range propagation and the quantum communication can be really realized.
@article{arxiv.1509.08554,
title = {Quantum entanglement degrees amplifier},
author = {Xiang-Yao Wu and Ji Ma and Xiao-Jing Liu and Yu Liang and Xiang-Dong Meng and Hong Li and Si-Qi Zhang},
journal= {arXiv preprint arXiv:1509.08554},
year = {2015}
}