Efficient and faithful implementation of quantum information tasks, e.g., quantum computing, quantum communication and quantum metrology, requires robust and state-independent decoherence-suppressing measures to protect quantum information carriers. Here we present an experimental demonstration of a robust distribution scheme in which one photon of an entangled photon pair is successfully encoded into and decoded from a decoherence-free subspace (DFS) by a state-independent scheme. We achieved a high-fidelity distribution of the entangled state over fibre communication channel, and also demonstrated that the scheme is robust against fragility of the reference frame. The scheme, thanks to its state-independence, is also applicable to multipartite case where the photon to be distributed is entangled with many other photons. Such a universal scheme opens the possibility of robust distribution of quantum information among quantum communication and computing networks.
@article{arxiv.0806.2896,
title = {Robust photonic entanglement distribution via state-independent encoding onto decoherence-free subspace},
author = {Takashi Yamamoto and Kodai Hayashi and Sahin Kaya Ozdemir and Masato Koashi and Nobuyuki Imoto},
journal= {arXiv preprint arXiv:0806.2896},
year = {2008}
}