Quantum repeaters for communication
  In quantum communication via noisy channels, the error probability scales exponentially with the length of the channel. We present a scheme of a quantum repeater that overcomes this limitation. The central idea is to connect a string of (imperfect) entangled pairs of particles by using a novel nested purification protocol, thereby creating a single distant pair of high fidelity. The scheme tolerates general errors on the percent level. 
H.-J. Briegel, W. D\"ur, J. I. Cirac, and P. Zoller