title: Quantum metrology with two-mode squeezed vacuum: parity detection beats the Heisenberg limit.
abstract: We study the sensitivity and resolution of phase measurement in a Mach-Zehnder interferometer with two-mode squeezed vacuum (n photons on average). We show that superresolution and sub-Heisenberg sensitivity is obtained with parity detection. In particular, in our setup, dependence of the signal on the phase evolves n times faster than in traditional schemes, and uncertainty in the phase estimation is better than 1/n, and we saturate the quantum Cramer-Rao bound.
authors.affiliation: Hearne Institute for Theoretical Physics and Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA. petr@lsu.edu
authors.forename: Petr M
authors.initials: PM
authors.lastname: Anisimov
authors.forename: Gretchen M
authors.initials: GM
authors.lastname: Raterman
authors.forename: Aravind
authors.initials: A
authors.lastname: Chiruvelli
authors.forename: William N
authors.initials: WN
authors.lastname: Plick
authors.forename: Sean D
authors.initials: SD
authors.lastname: Huver
authors.forename: Hwang
authors.initials: H
authors.lastname: Lee
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Dowling