Practical quantum metrology in noisy environments
The problem of estimating an unknown phase ϕ using two-level probes in the presence of unital phase-covariant noise and using finite resources is investigated. We introduce a simple model in which the phase-imprinting operation on the probes is realized by a unitary transformation with a randomly sa...
| Main Authors: | , , , |
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| Format: | Article |
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American Physical Society
2016
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| Online Access: | https://eprints.nottingham.ac.uk/45296/ |
| _version_ | 1848797107329171456 |
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| author | Nichols, Rosanna Bromley, Thomas R. Correa, Luis A. Adesso, Gerardo |
| author_facet | Nichols, Rosanna Bromley, Thomas R. Correa, Luis A. Adesso, Gerardo |
| author_sort | Nichols, Rosanna |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | The problem of estimating an unknown phase ϕ using two-level probes in the presence of unital phase-covariant noise and using finite resources is investigated. We introduce a simple model in which the phase-imprinting operation on the probes is realized by a unitary transformation with a randomly sampled generator. We determine the optimal phase sensitivity in a sequential estimation protocol and derive a general (tight-fitting) lower bound. The sensitivity grows quadratically with the number of applications N of the phase-imprinting operation, then attains a maximum at some Nopt, and eventually decays to zero. We provide an estimate of Nopt in terms of accessible geometric properties of the noise and illustrate its usefulness as a guideline for optimizing the estimation protocol. The use of passive ancillas and of entangled probes in parallel to improve the phase sensitivity is also considered .We find that multiprobe entanglement may offer no practical advantage over single-probe coherence if the interrogation at the output is restricted to measuring local observables. |
| first_indexed | 2025-11-14T19:58:37Z |
| format | Article |
| id | nottingham-45296 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:58:37Z |
| publishDate | 2016 |
| publisher | American Physical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-452962020-05-04T18:18:11Z https://eprints.nottingham.ac.uk/45296/ Practical quantum metrology in noisy environments Nichols, Rosanna Bromley, Thomas R. Correa, Luis A. Adesso, Gerardo The problem of estimating an unknown phase ϕ using two-level probes in the presence of unital phase-covariant noise and using finite resources is investigated. We introduce a simple model in which the phase-imprinting operation on the probes is realized by a unitary transformation with a randomly sampled generator. We determine the optimal phase sensitivity in a sequential estimation protocol and derive a general (tight-fitting) lower bound. The sensitivity grows quadratically with the number of applications N of the phase-imprinting operation, then attains a maximum at some Nopt, and eventually decays to zero. We provide an estimate of Nopt in terms of accessible geometric properties of the noise and illustrate its usefulness as a guideline for optimizing the estimation protocol. The use of passive ancillas and of entangled probes in parallel to improve the phase sensitivity is also considered .We find that multiprobe entanglement may offer no practical advantage over single-probe coherence if the interrogation at the output is restricted to measuring local observables. American Physical Society 2016-10-03 Article PeerReviewed Nichols, Rosanna, Bromley, Thomas R., Correa, Luis A. and Adesso, Gerardo (2016) Practical quantum metrology in noisy environments. Physical Review A, 94 (4). 042101/1-042101/10. ISSN 2469-9926 https://journals.aps.org/pra/abstract/10.1103/PhysRevA.94.042101 doi:10.1103/PhysRevA.94.042101 doi:10.1103/PhysRevA.94.042101 |
| spellingShingle | Nichols, Rosanna Bromley, Thomas R. Correa, Luis A. Adesso, Gerardo Practical quantum metrology in noisy environments |
| title | Practical quantum metrology in noisy environments |
| title_full | Practical quantum metrology in noisy environments |
| title_fullStr | Practical quantum metrology in noisy environments |
| title_full_unstemmed | Practical quantum metrology in noisy environments |
| title_short | Practical quantum metrology in noisy environments |
| title_sort | practical quantum metrology in noisy environments |
| url | https://eprints.nottingham.ac.uk/45296/ https://eprints.nottingham.ac.uk/45296/ https://eprints.nottingham.ac.uk/45296/ |