Optimal lossy quantum interferometry in phase space

Autor: Andrei B Klimov, Marcin Zwierz, Sascha Wallentowitz, Marcin Jarzyna, Konrad Banaszek
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: New Journal of Physics, Vol 19, Iss 7, p 073013 (2017)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/aa73b0
Popis: 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.
Databáze: Directory of Open Access Journals