Non-adaptive Heisenberg-limited metrology with multi-channel homodyne measurements
School of Mathematics and Physics, University of Portsmouth, PO1 3QL, Portsmouth, UK
2 Dipartimento di Fisica and MECENAS, Università di Bari, 70126, Bari, Italy
3 INFN, Sezione di Bari, 70126, Bari, Italy
4 Institute of Cosmology and Gravitation, University of Portsmouth, PO1 3FX, Portsmouth, UK
Accepted: 29 December 2021
Published online: 17 January 2022
We show a protocol achieving the ultimate Heisenberg-scaling sensitivity in the estimation of a parameter encoded in a generic linear network, without employing any auxiliary networks, and without the need of any prior information on the parameter nor on the network structure. As a result, this protocol does not require a prior coarse estimation of the parameter, nor an adaptation of the network. The scheme we analyse consists of a single-mode squeezed state and homodyne detectors in each of the M output channels of the network encoding the parameter, making it feasible for experimental applications.
© The Author(s) 2022
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.