Distributed quantum metrology with a single squeezed-vacuum source

Dario Gatto,Vincenzo Tamma,Frank A Narducci,Paolo Facchi

doi:10.1103/physrevresearch.1.032024

Abstract

We propose an interferometric scheme for the estimation of a linear combination with non-negative weights of an arbitrary number $M>1$ of unknown phase delays, distributed across an $M$-channel linear optical network, with Heisenberg-limited sensitivity. This is achieved without the need of any sources of photon-number or entangled states, photon-number resolving detectors or auxiliary interferometric channels. Indeed, the proposed protocol remarkably relys upon a single squeezed state source, an antisqueezing operation at the interferometer output, and on-off photodetectors.

Highlights

Introduction and motivationsQuantum metrology aims at harnessing inherently quantum features such as entanglement, multiphoton interference, and squeezing, to develop novel quantum enhanced technologies for sensing and imaging beyond any classical capabilities [1,2,3,4,5,6,7,8]
We propose an interferometric scheme for the estimation of a linear combination with non-negative weights of an arbitrary number M > 1 of unknown phase delays, distributed across an M-channel linear optical network, with Heisenberg-limited sensitivity
A great deal of attention has been devoted to distributed quantum metrology, on the problem of measuring a linear combination of several unknown phase shifts distributed over a linear optical network [9,10,11,12,13,14]

Summary

Rapid Communications

Dario Gatto ,1,* Paolo Facchi ,2,3 Frank A. We propose an interferometric scheme for the estimation of a linear combination with non-negative weights of an arbitrary number M > 1 of unknown phase delays, distributed across an M-channel linear optical network, with Heisenberg-limited sensitivity. We demonstrate how a simple M-channel linear optical interferometer with only a single squeezed-vacuum source and on-off photodetectors can achieve Heisenberg-limited sensitivity in distributed quantum metrology with M unknown phase delays. Such a scheme can be implemented experimentally with present quantum optical technologies.

Published by the American Physical Society

Discussion