Knott, P A, Proctor, T J, Hayes, A J, Ralph, J F, Kok, P and Dunningham, J A (2016) Local versus global strategies in multi-parameter estimation. Physical Review A, 94 (6). a2312. ISSN 1050-2947
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Abstract
We consider the problem of estimating multiple phases using a multi-mode interferometer. In this setting we show that while global strategies that estimate all the phases simultaneously can lead to high precision gains, the same enhancements can be obtained with local strategies where each phase is estimated individually. A key resource for the enhancement is shown to be a large particle-number variance in the probe state, and for states where the total particle number is not fixed, this can be obtained for mode-separable states and the phases can be read out with local measurements. This has important practical implications because local strategies are generally preferred to global ones for their robustness to local estimation failure, flexibility in the distribution of resources, and comparatively easier state preparation. We obtain our results by analyzing two different schemes: the first uses a set of interferometers, which can be used as a model for a network of quantum sensors, and the second looks at measuring a number of phases relative to a reference, which is concerned primarily with quantum imaging.
Item Type: | Article |
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Schools and Departments: | School of Mathematical and Physical Sciences > Physics and Astronomy |
Research Centres and Groups: | Atomic, Molecular and Optical Physics Research Group |
Subjects: | Q Science > QC Physics |
Depositing User: | Richard Chambers |
Date Deposited: | 22 Nov 2016 11:39 |
Last Modified: | 09 Sep 2017 19:46 |
URI: | http://srodev.sussex.ac.uk/id/eprint/65580 |
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📧 Request an updateProject Name | Sussex Project Number | Funder | Funder Ref |
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UK Quantum Technology Hub: NQIT-Networked Quantum Information Technologies | G1503 | EPSRC-ENGINEERING & PHYSICAL SCIENCES RESEARCH COUNCIL | EP/M013243/1 |