Quantum telecommunication with atomic ensembles

Abstract
Quantum mechanics provides a mechanism for absolutely secure communication between remote parties. For distances greater than 100 km, direct quantum communication via optical fiber is not viable, owing to fiber losses, and intermediate storage of the quantum information along the transmission channel is necessary. This leads to the concept of the quantum repeater, proposed by Briegel et al. [Phys. Rev. Lett. 81, 169 (1998) ]. Duan et al. [Nature 414, 413 (2001) ] have proposed to use atomic ensembles as the basic memory elements for the quantum repeater. We provide an overview of our program on the use of atomic ensembles as an interface for quantum information transfer and the prospects for long-distance quantum networks.