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Quantum Noise Limits for Nonlinear, Phase-Invariant Amplifiers

Dmitri Kouznetsov·Roberto Ortega·Daniel Rohrlich
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Abstract

Any quantum device that amplifies coherent states of a field while preserving their phase generates noise. A nonlinear, phase-invariant amplifier may generate less noise, over a range of input field strengths, than any linear amplifier with the same amplification. We present explicit examples of such nonlinear amplifiers, and derive lower bounds on the noise generated by a nonlinear, phase-invariant quantum amplifier.

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Dmitri Kouznetsov, Roberto Ortega, Daniel Rohrlich. 1994-07-03. Quantum Noise Limits for Nonlinear, Phase-Invariant Amplifiers. https://doi.org/10.1103/physreva.52.1665

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