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Gaussian interferometric power

Adesso, Gerardo

Authors



Abstract

The interferometric power of a bipartite quantum state quantifies the precision, measured by quantum Fisher information, that such a state enables for the estimation of a parameter embedded in a unitary dynamics applied to one subsystem only, in the worst-case scenario where a full knowledge of the generator of the dynamics is not available a priori. For finite-dimensional systems, this quantity was proven to be a faithful measure of quantum correlations beyond entanglement. Here we extend the notion of interferometric power to the technologically relevant setting of optical interferometry with continuous-variable probes. By restricting to Gaussian local dynamics, we obtain a closed formula for the interferometric power of all two-mode Gaussian states. We identify separable and entangled Gaussian states which maximize the interferometric power at fixed mean photon number of the probes and discuss the associated metrological scaling. At fixed entanglement of the probes, highly thermalized states can guarantee considerably larger precision than pure two-mode squeezed states.

Citation

Adesso, G. (2014). Gaussian interferometric power. Physical Review A, 90(2), https://doi.org/10.1103/PhysRevA.90.022321

Journal Article Type Article
Acceptance Date Jun 20, 2014
Publication Date Aug 20, 2014
Deposit Date Oct 11, 2017
Publicly Available Date Oct 11, 2017
Journal Physical Review A
Print ISSN 2469-9926
Electronic ISSN 2469-9934
Publisher American Physical Society
Peer Reviewed Peer Reviewed
Volume 90
Issue 2
DOI https://doi.org/10.1103/PhysRevA.90.022321
Public URL http://eprints.nottingham.ac.uk/id/eprint/47212
Publisher URL https://journals.aps.org/pra/abstract/10.1103/PhysRevA.90.022321
Copyright Statement Copyright information regarding this work can be found at the following address: http://eprints.nottingh.../end_user_agreement.pdf
Additional Information ©2014 American Physical Society

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Copyright Statement
Copyright information regarding this work can be found at the following address: http://eprints.nottingham.ac.uk/end_user_agreement.pdf





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