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arXiv:1705.00065 · New Journal of Physics

Optimal lossy quantum interferometry in phase space

A. B. Klimov, Marcin Zwierz, Sascha Wallentowitz, Marcin Jarzyna, Konrad Banaszek

Published May 17, 2017• 6 citations
arXivHTMLPDF

Abstract

We analyse the phase space representation of the optimal measurement of a phase shift in an interferometer with equal photon loss in both its arms. In the local phase estimation scenario with a fixed number of photons, we identify features of the spin Wigner function that warrant sub-shot-noise precision, and discuss their sensitivity to losses. We derive the asymptotic form of an integral kernel describing the process of photon loss in the phase space in the limit of large photon numbers. The analytic form of this kernel allows one to assess the ultimate precision limit for a lossy interferometer. We also provide a general lower bound on the quantum Fisher information in terms of spin Wigner functions.

DOI
10.1088/1367-2630/aa73b0

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