Quantum telecommunication based on atomic cascade transitions
  A quantum repeater at telecommunications wavelengths with long-lived atomic memory is proposed, and its critical elements are experimentally demonstrated using a cold atomic ensemble. Via atomic cascade emission, an entangled pair of 1530 nm and 780 nm photons is generated. The former is ideal for long-distance quantum communication, and the latter is naturally suited for mapping to a long-lived atomic memory. Together with our previous demonstration of photonic-to-atomic qubit conversion, both of the essential elements for the proposed telecommunications quantum repeater have now been realized. 
T. Chaneliere, D. N. Matsukevich, S. D. Jenkins, T. A. B. Kennedy, M.   S. Chapman, and A. Kuzmich