School of Mathematical Sciences

Quantum scale metrology: highly precise measurements beyond phase estimation

Wednesday 22nd March 2023 (13:00-14:00)
Event Convenor Contact:
Speaker's Name: Dr. Jesús Rubio
Speaker's Affiliation: Department of Physics and Astronomy, University of Exeter
Speaker's Research Theme(s): Quantum information and metrology,
Whether quantum technologies are ultimately successful will depend on our ability to perform highly precise measurements. This has led to an in-depth revision of the foundations of quantum metrology beyond the traditional framework of phase estimation. For instance, for regimes with finite data sets, incompatible estimators, and parameter types other than phases. In this talk, quantum scale metrology is established as the most precise framework for the estimation of scale parameters that is allowed by the laws of quantum mechanics. For given prior probability and quantum state, and using Bayesian principles, a rule to construct the optimal probability-operator measurement is identified. Moreover, the corresponding minimum mean logarithmic error is calculated. This is then generalised as to accommodate the simultaneous estimation of multiple scale parameters. As a means of illustration, the new framework is applied to global thermometry and the estimation of the lifetime of an atomic state. On a more conceptual note, the optimal strategy is employed to construct an observable for scale parameters, an approach which may serve as a template for a more systematic search of quantum observables. Quantum scale metrology is thus argued to open a new line of enquire—the precise measurement of scale parameters such as temperatures and rates—within the quantum information sciences. J. Rubio, Quantum Sci. Technol. 8 015009 (2022) J. Rubio, J. Anders and L. A. Correa, Phys. Rev. Lett., 127:190402 (2021) R. Demkowicz-Dobrzański, W. Górecki and M. Guţă, J. Phys. A: Math. Theor. 53 363001 (2020)

Venue: C29, School of Physics and Astronomy

School of Mathematical Sciences

The University of Nottingham
University Park
Nottingham, NG7 2RD

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