English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

A proposed phase-estimation protocol based on measuring the parity of atwo-mode squeezed-vacuum state at the output of a Mach-Zehnder interferometershows that the Cram\'{e}r-Rao sensitivity is sub-Heisenberg [Phys.\ Rev.\Lett.\ {\bf104}, 103602 (2010)]. However, these measurements are problematic,making it unclear if this sensitivity can be obtained with a finite number ofmeasurements. This sensitivity is only for phase near zero, and in this regionthere is a problem with ambiguity because measurements cannot distinguish thesign of the phase. Here, we consider a finite number of parity measurements,and show that an adaptive technique gives a highly accurate phase estimateregardless of the phase. We show that the Heisenberg limit is reachable, wherethe number of trials needed for mean photon number $\bar{n}=1$ is approximatelyone hundred. We show that the Cram\'{e}r-Rao sensitivity can be achievedapproximately, and the estimation is unambiguous in the interval ($-\pi/2,\pi/2$).

Adaptive phase estimation with two-mode squeezed-vacuum and parity measurement