title: Low-noise amplification of a continuous-variable quantum state.
abstract: We present an experimental realization of a low-noise, phase-insensitive optical amplifier using a four-wave mixing interaction in hot Rb vapor. Performance near the quantum limit for a range of amplifier gains, including near unity, can be achieved. Such low-noise amplifiers are essential for so-called quantum cloning machines and are useful in quantum information protocols. We demonstrate that amplification and "cloning" of one half of a two-mode squeezed state is possible while preserving entanglement.
authors: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA. rpooser@nist.gov
authors: R C
authors: RC
authors: Pooser
authors: A M
authors: AM
authors: Marino
authors: V
authors: V
authors: Boyer
authors: K M
authors: KM
authors: Jones
authors: P D
authors: PD
authors: Lett