Gaussian interferometric power

Adesso, Gerardo (2014) Gaussian interferometric power. Physical Review A, 90 (2). 022321-1-022321-6. ISSN 2469-9934

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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.

Item Type: Article
Additional Information: ©2014 American Physical Society
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Mathematical Sciences
Identification Number: 10.1103/PhysRevA.90.022321
Depositing User: Eprints, Support
Date Deposited: 11 Oct 2017 14:38
Last Modified: 12 Oct 2017 15:27
URI: http://eprints.nottingham.ac.uk/id/eprint/47212

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