Intuitive reason for the usefulness of entanglement in quantum metrology
نویسندگان
چکیده
منابع مشابه
Quantum metrology: dynamics versus entanglement.
A parameter whose coupling to a quantum probe of n constituents includes all two-body interactions between the constituents can be measured with an uncertainty that scales as 1/n3/2, even when the constituents are initially unentangled. We devise a protocol that achieves the 1/n3/2 scaling without generating any entanglement among the constituents, and we suggest that the protocol might be impl...
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Using entanglement against noise in quantum metrology [1]
FIG. 1. Quantum metrology strategies. The maps Λφ encode the parameter φ to be estimated. (i) sequential scheme: Λφ acts n times sequentially on N/n input probes ρ (this is an entanglement-free classical scheme) ; (ii) entangled parallel scheme: an entangled state of N probes ρN goes through N maps Λφ in parallel; (iii) passive ancilla scheme: the N probes are also entangled with M noiseless an...
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P. A. Knott,1,2,* T. J. Proctor,1 Kae Nemoto,3 J. A. Dunningham,4 and W. J. Munro2,3 1School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom 2NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan 3National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan 4Department of Physics and A...
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ژورنال
عنوان ژورنال: Physical Review A
سال: 2013
ISSN: 1050-2947,1094-1622
DOI: 10.1103/physreva.88.042109