Sub-Heisenberg phase uncertainties
Authors: Pezzè L.
Autors Affiliation: QSTAR, INO-CNR and LENS, Largo Enrico Fermi 2, 50125 Firenze, Italy
Abstract: Phase shift estimation with uncertainty below the Heisenberg limit, Delta phi(HL) alpha 1/(N) over bar (T), where (N) over bar (T) is the total average number of particles employed, is a mirage of linear quantum interferometry. Recently, Rivas and Luis, [New J. Phys. 14, 093052 (2012)] proposed a scheme to achieve a phase uncertainty Delta phi(HL) alpha 1/(N) over bar (k)(T), with k an arbitrary exponent. This sparked an intense debate in the literature which, ultimately, does not exclude the possibility to overcome Delta phi(HL) at specific phase values. Our numerical analysis of the Rivas and Luis proposal shows that sub-Heisenberg uncertainties are obtained only when the estimator is strongly biased. No violation of the Heisenberg limit is found after bias correction or when using a bias-free Bayesian analysis.
Journal/Review: PHYSICAL REVIEW A
Volume: 88 (6) Pages from: 060101 to: 060101
More Information: We thank A. Smerzi and H. Wiseman for discussions. This work has been supported by MIUR through FIRB Project No. RBFR08H058.DOI: 10.1103/PhysRevA.88.060101Citations: 10data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2019-10-13References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here