Multiparameter estimation in networked quantum sensors
We introduce a general model for a network of quantum sensors, and we use this model to consider the following question: When can entanglement between the sensors, and/or global measurements, enhance the precision with which the network can measure a set of unknown parameters? We rigorously answer t...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2018
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| Online Access: | https://eprints.nottingham.ac.uk/51260/ |
| _version_ | 1848798453798273024 |
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| author | Proctor, Timothy J. Knott, Paul A. Dunningham, Jacob A. |
| author_facet | Proctor, Timothy J. Knott, Paul A. Dunningham, Jacob A. |
| author_sort | Proctor, Timothy J. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We introduce a general model for a network of quantum sensors, and we use this model to consider the following question: When can entanglement between the sensors, and/or global measurements, enhance the precision with which the network can measure a set of unknown parameters? We rigorously answer this question by presenting precise theorems proving that for a broad class of problems there is, at most, a very limited intrinsic advantage to using entangled states or global measurements. Moreover, for many estimation problems separable states and local measurements are optimal, and can achieve the ultimate quantum limit on the estimation uncertainty. This immediately implies that there are broad conditions under which simultaneous estimation of multiple parameters cannot outperform individual, independent estimations. Our results apply to any situation in which spatially localized sensors are unitarily encoded with independent parameters, such as when estimating multiple linear or nonlinear optical phase shifts in quantum imaging, or when mapping out the spatial profile of an unknown magnetic field. We conclude by showing that entangling the sensors can enhance the estimation precision when the parameters of interest are global properties of the entire network. |
| first_indexed | 2025-11-14T20:20:01Z |
| format | Article |
| id | nottingham-51260 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T20:20:01Z |
| publishDate | 2018 |
| publisher | American Physical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-512602018-04-19T11:56:48Z https://eprints.nottingham.ac.uk/51260/ Multiparameter estimation in networked quantum sensors Proctor, Timothy J. Knott, Paul A. Dunningham, Jacob A. We introduce a general model for a network of quantum sensors, and we use this model to consider the following question: When can entanglement between the sensors, and/or global measurements, enhance the precision with which the network can measure a set of unknown parameters? We rigorously answer this question by presenting precise theorems proving that for a broad class of problems there is, at most, a very limited intrinsic advantage to using entangled states or global measurements. Moreover, for many estimation problems separable states and local measurements are optimal, and can achieve the ultimate quantum limit on the estimation uncertainty. This immediately implies that there are broad conditions under which simultaneous estimation of multiple parameters cannot outperform individual, independent estimations. Our results apply to any situation in which spatially localized sensors are unitarily encoded with independent parameters, such as when estimating multiple linear or nonlinear optical phase shifts in quantum imaging, or when mapping out the spatial profile of an unknown magnetic field. We conclude by showing that entangling the sensors can enhance the estimation precision when the parameters of interest are global properties of the entire network. American Physical Society 2018-02-23 Article PeerReviewed application/pdf en https://eprints.nottingham.ac.uk/51260/2/PhysRevLett.120.080501 Proctor, Timothy J., Knott, Paul A. and Dunningham, Jacob A. (2018) Multiparameter estimation in networked quantum sensors. Physical Review Letters, 120 (8). 080501. ISSN 1079-7114 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.080501 doi:10.1103/PhysRevLett.120.080501 doi:10.1103/PhysRevLett.120.080501 |
| spellingShingle | Proctor, Timothy J. Knott, Paul A. Dunningham, Jacob A. Multiparameter estimation in networked quantum sensors |
| title | Multiparameter estimation in networked quantum sensors |
| title_full | Multiparameter estimation in networked quantum sensors |
| title_fullStr | Multiparameter estimation in networked quantum sensors |
| title_full_unstemmed | Multiparameter estimation in networked quantum sensors |
| title_short | Multiparameter estimation in networked quantum sensors |
| title_sort | multiparameter estimation in networked quantum sensors |
| url | https://eprints.nottingham.ac.uk/51260/ https://eprints.nottingham.ac.uk/51260/ https://eprints.nottingham.ac.uk/51260/ |