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- Publisher Website: 10.1103/PhysRevLett.124.190503
- Scopus: eid_2-s2.0-85085659132
- PMID: 32469602
- WOS: WOS:000615281400001
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Article: Quantum Metrology with Indefinite Causal Order
Title | Quantum Metrology with Indefinite Causal Order |
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Authors | |
Issue Date | 2020 |
Publisher | American Physical Society. The Journal's web site is located at https://journals.aps.org/prl/ |
Citation | Physical Review Letters, 2020, v. 124 n. 19, article no. 190503 How to Cite? |
Abstract | We address the study of quantum metrology enhanced by indefinite causal order, demonstrating a quadratic advantage in the estimation of the product of two average displacements in a continuous variable system. We prove that no setup where the displacements are used in a fixed order can have root-mean-square error vanishing faster than the Heisenberg limit 1/N, where N is the number of displacements contributing to the average. In stark contrast, we show that a setup that probes the displacements in a superposition of two alternative orders yields a root-mean-square error vanishing with super-Heisenberg scaling 1/N2, which we prove to be optimal among all superpositions of setups with definite causal order. Our result opens up the study of new measurement setups where quantum processes are probed in an indefinite order, and suggests enhanced tests of the canonical commutation relations, with potential applications to quantum gravity. |
Persistent Identifier | http://hdl.handle.net/10722/284903 |
ISSN | 2023 Impact Factor: 8.1 2023 SCImago Journal Rankings: 3.040 |
ISI Accession Number ID |
DC Field | Value | Language |
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dc.contributor.author | Zhao, X | - |
dc.contributor.author | Yang, Y | - |
dc.contributor.author | Chiribella, G | - |
dc.date.accessioned | 2020-08-07T09:04:08Z | - |
dc.date.available | 2020-08-07T09:04:08Z | - |
dc.date.issued | 2020 | - |
dc.identifier.citation | Physical Review Letters, 2020, v. 124 n. 19, article no. 190503 | - |
dc.identifier.issn | 0031-9007 | - |
dc.identifier.uri | http://hdl.handle.net/10722/284903 | - |
dc.description.abstract | We address the study of quantum metrology enhanced by indefinite causal order, demonstrating a quadratic advantage in the estimation of the product of two average displacements in a continuous variable system. We prove that no setup where the displacements are used in a fixed order can have root-mean-square error vanishing faster than the Heisenberg limit 1/N, where N is the number of displacements contributing to the average. In stark contrast, we show that a setup that probes the displacements in a superposition of two alternative orders yields a root-mean-square error vanishing with super-Heisenberg scaling 1/N<font size=-1><sup>2</sup></font>, which we prove to be optimal among all superpositions of setups with definite causal order. Our result opens up the study of new measurement setups where quantum processes are probed in an indefinite order, and suggests enhanced tests of the canonical commutation relations, with potential applications to quantum gravity. | - |
dc.language | eng | - |
dc.publisher | American Physical Society. The Journal's web site is located at https://journals.aps.org/prl/ | - |
dc.relation.ispartof | Physical Review Letters | - |
dc.rights | Copyright 2020 by The American Physical Society. This article is available online at http://dx.doi.org/10.1103/PhysRevLett.124.190503. | - |
dc.title | Quantum Metrology with Indefinite Causal Order | - |
dc.type | Article | - |
dc.identifier.email | Chiribella, G: giulio@cs.hku.hk | - |
dc.identifier.authority | Chiribella, G=rp02035 | - |
dc.description.nature | published_or_final_version | - |
dc.identifier.doi | 10.1103/PhysRevLett.124.190503 | - |
dc.identifier.pmid | 32469602 | - |
dc.identifier.scopus | eid_2-s2.0-85085659132 | - |
dc.identifier.hkuros | 312272 | - |
dc.identifier.volume | 124 | - |
dc.identifier.issue | 19 | - |
dc.identifier.spage | article no. 190503 | - |
dc.identifier.epage | article no. 190503 | - |
dc.identifier.isi | WOS:000615281400001 | - |
dc.publisher.place | United States | - |
dc.identifier.issnl | 0031-9007 | - |