Efficient Decoherence-Free Entanglement Distribution over Lossy Quantum Channels
Rikizo Ikuta, Yohei Ono, Toshiyuki Tashima, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto · Physical Review Letters · 2011
We propose and demonstrate a scheme for boosting the efficiency of entanglement distribution based on a decoherence-free subspace over lossy quantum channels. By using backward propagation of a coherent light, our scheme achieves an entanglement-sharing rate that is proportional to the transmittance T of the quantum channel in spite of encoding qubits in multipartite systems for the decoherence-free subspace. We experimentally show that highly entangled states, which can violate the Clauser-Horne-Shimony-Holt inequality, are distributed at a rate proportional to T.