One-shot entanglement generation over long distances in noisy quantum   networks
  We consider the problem of creating a long-distance entangled state between two stations of a network, where neighboring nodes are connected by noisy quantum channels. We show that any two stations can share an entangled pair if the effective probability for the quantum errors is below a certain threshold, which is achieved by using local redundant encoding to preserve the global phase and network-based correction for the bit-flip errors. In contrast to the convensional quantum repeater schemes we are not limited by the memory coherence time, because all quantum operations only use one-way classical communication and can be done in one shot. Meanwhile, the overhead of local resources only increases logarithmically with the size of the network, making our proposal favorable to practical applications of long-distance quantum communication. 
S. Perseguers, L. Jiang, N. Schuch, F. Verstraete, M.D. Lukin, J.I.   Cirac, and K.G.H. Vollbrecht