Gaussian quantum metrology and space-time probes

Šafránek, Dominik (2016) Gaussian quantum metrology and space-time probes. PhD thesis, University of Nottingham.

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Abstract

In this thesis we focus on Gaussian quantum metrology in the phase-space formalism and its applications in quantum sensing and the estimation of space-time parameters. We derive new formulae for the optimal estimation of multiple parameters encoded into Gaussian states. We discuss the discontinuous behavior of the figure of merit -- the quantum Fisher information. Using derived expressions we devise a practical method of finding optimal probe states for the estimation of Gaussian channels and we illustrate this method on several examples. We show that the temperature of a probe state affects the estimation generically and always appears in the form of four multiplicative factors. We also discuss how well squeezed thermal states perform in the estimation of space-time parameters. Finally we study how the estimation precision changes when two parties exchanging a quantum state with the encoded parameter do not share a reference frame. We show that using a quantum reference frame could counter this effect.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Fuentes Guridi, Ivette
Louko, Jorma
Mumford, Stephen
Keywords: quantum metrology, Gaussian states, space-time parameters, quantum reference frames
Subjects: Q Science > QA Mathematics > QA 75 Electronic computers. Computer science
Q Science > QC Physics > QC170 Atomic physics. Constitution and properties of matter
Faculties/Schools: UK Campuses > Faculty of Science > School of Mathematical Sciences
Item ID: 37124
Depositing User: Šafránek, Dominik
Date Deposited: 14 Dec 2016 06:40
Last Modified: 15 Dec 2016 05:07
URI: http://eprints.nottingham.ac.uk/id/eprint/37124

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