On quantumness in multi-parameter quantum estimation
Abstract
In this article we derive a measure of quantumness in quantum multi-parameter estimation problems. We can show that the ratio between the mean Uhlmann Curvature and the Fisher Information provides a figure of merit which estimates the amount of incompatibility arising from the quantum nature of the underlying physical system. This ratio accounts for the discrepancy between the attainable precision in the simultaneous estimation of multiple parameters and the precision predicted by the Cram\'er-Rao bound. As a testbed for this concept, we consider a quantum many-body system in thermal equilibrium, and explore the quantum compatibility of the model across its phase diagram.
Cite
@article{arxiv.1911.11621,
title = {On quantumness in multi-parameter quantum estimation},
author = {Angelo Carollo and Bernardo Spagnolo and Alexander A. Dubkov and Davide Valenti},
journal= {arXiv preprint arXiv:1911.11621},
year = {2020}
}
Comments
21 pages, 2 Figures. arXiv admin note: text overlap with arXiv:1911.10196