Ultrasensitive Two-Mode Interferometry with Single-Mode Number Squeezing
Authors: Pezze L., Smerzi A.
Autors Affiliation: QSTAR, INO-CNR and LENS, Largo Enrico Fermi 2, 50125 Firenze, Italy
Abstract: A major challenge of the phase estimation problem is the engineering of high-intensity entangled probe states. The goal is to significantly enhance above the shot-noise limit the sensitivity of two-mode interferometers. Here we show that this can be achieved by squeezing in input, and then measuring in output, the population fluctuations of a single mode. The second input mode can be left as an arbitrary nonvacuum (e. g., a bright coherent) state. This two-mode state belongs to a novel class of particle-entangled states which are not spin squeezed. Already a 2.4 db gain above shot noise can be obtained when just a single-particle Fock state is injected into the empty input port of a classical interferometer configuration. Higher gains, up to the Heisenberg limit, can be reached with squeezed states of a larger number of particles. We finally study the robustness of this protocol with respect to detection noise. DOI: 10.1103/PhysRevLett.110.163604
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 110 (16) Pages from: 163604 to: 163604
More Information: We thank M. Barbieri, A. Bertoldi, P. Hyllus, C. Klempt, and L. Santos for discussions. This work has been supported by the EU-STREP Project QIBEC. L. P. acknowledges financial support by MIUR through FIRB Project No. RBFR08H058. QSTAR is the MPQ, IIT, LENS, UniFi joint center for Quantum Science and Technology in Arcetri.DOI: 10.1103/PhysRevLett.110.163604Citations: 55data 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