Quantum Cloning of a Coherent Light State into an Atomic Quantum Memory

Jaromír Fiurášek, Nicolas J. Cerf, Eugene S. Polzik
2004 Physical Review Letters  
A scheme for the optimal Gaussian cloning of coherent light states at the light-atoms interface is proposed. The distinct feature of this proposal is that the clones are stored in an atomic quantum memory, which is important for applications in quantum communication. The atomic quantum cloning machine requires only a single passage of the light pulse through the atomic ensembles followed by the measurement of a light quadrature and an appropriate feedback, which renders the protocol
more » ... ly feasible. An alternative protocol, where one of the clones is carried by the outgoing light pulse, is discussed in connection with quantum key distribution.
doi:10.1103/physrevlett.93.180501 pmid:15525141 fatcat:ajcgubdrsredlcc3xa6txzc33y