Experimental characterization of continuous-variable entanglement

Journal Article · Thu Jan 01 04:00:00 EST 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.69.012304· OSTI ID:20640584

Bowen, W P; Schnabel, R; Lam, P K; Ralph, T C ^[1]

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1. Department of Physics, Faculty of Science, Australian National University, Australian Capital Territory 0200 (Australia)

We present an experimental analysis of quadrature entanglement produced from a pair of amplitude squeezed beams. The correlation matrix of the state is characterized within a set of reasonable assumptions, and the strength of the entanglement is gauged using measures of the degree of inseparability and the degree of Einstein-Podolsky-Rosen (EPR) paradox. We introduce controlled decoherence in the form of optical loss to the entangled state, and demonstrate qualitative differences in the response of the degrees of inseparability and EPR paradox to this loss. The entanglement is represented on a photon number diagram that provides an intuitive and physically relevant description of the state. We calculate efficacy contours for several quantum information protocols on this diagram, and use them to predict the effectiveness of our entanglement in those protocols.

• OSTI ID: 20640584
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 69; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
AMPLITUDES
CORRELATIONS
DIAGRAMS
ELECTRON SPIN RESONANCE
INFORMATION THEORY
LOSSES
PHOTONS
QUADRATURES
QUANTUM MECHANICS