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arXiv · 1108.6002

Useful Multiparticle Entanglement and Sub-Shot-Noise Sensitivity in Experimental Phase Estimation

Roland Krischek·Christian Schwemmer·Witlef Wieczorek·Harald Weinfurter·Philipp Hyllus·Luca Pezzé·Augusto Smerzi
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Abstract

We experimentally demonstrate a general criterion to identify entangled states useful for the estimation of an unknown phase shift with a sensitivity higher than the shot-noise limit. We show how to exploit this entanglement on the examples of a maximum likelihood as well as of a Bayesian phase estimation protocol. Using an entangled four-photon state we achieve a phase sensitivity clearly beyond the shot-noise limit. Our detailed comparison of methods and quantum states for entanglement enhanced metrology reveals the connection between multiparticle entanglement and sub-shot-noise uncertainty, both in a frequentist and in a Bayesian phase estimation setting.

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Roland Krischek, Christian Schwemmer, Witlef Wieczorek, Harald Weinfurter, Philipp Hyllus, Luca Pezzé, Augusto Smerzi. 2011-08-30. Useful Multiparticle Entanglement and Sub-Shot-Noise Sensitivity in Experimental Phase Estimation. https://doi.org/10.1103/physrevlett.107.080504

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