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Title: Noise in phase-preserving linear amplifiers

The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state σ for the ancillary mode; σ determines the properties of the added noise.
Authors:
; ;  [1] ;  [2]
  1. Center for Quantum Information and Control, University of New Mexico, Albuquerque, NM 87131-0001 (United States)
  2. Center for Quantum Information and Control, University of New Mexico, Albuquerque, NM 87131-0001, USA and Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia)
Publication Date:
OSTI Identifier:
22390718
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1633; Journal Issue: 1; Conference: 11. International Conference on Quantum Communication, Measurement and Computation, Vienna (Austria), 30 Jul - 3 Aug 2012; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DATA PROCESSING; LIMITING VALUES; NOISE; PARAMETRIC AMPLIFIERS; QUANTUM MECHANICS; SIGNAL-TO-NOISE RATIO