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Quantum Communication with Correlated Nonclassical States

S. F. Pereira·Z. Y. Ou·H. J. Kimble
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Abstract

Nonclassical correlations between the quadrature-phase amplitudes of two spatially separated optical beams are exploited to realize a two-channel quantum communication experiment with a high degree of immunity to interception. For this scheme, either channel alone can have an arbitrarily small signal-to-noise ratio (SNR) for transmission of a coherent ``message''. However, when the transmitted beams are combined properly upon authorized detection, the encoded message can in principle be recovered with the original SNR of the source. An experimental demonstration has achieved a 3.2 dB improvement in SNR over that possible with correlated classical sources. Extensions of the protocol to improve its security against eavesdropping are discussed.

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S. F. Pereira, Z. Y. Ou, H. J. Kimble. 2000-03-21. Quantum Communication with Correlated Nonclassical States. https://doi.org/10.1103/physreva.62.042311

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