Multiparameter Gaussian Quantum Metrology
Abstract
We investigate the ultimate precision achievable in Gaussian quantum metrology. We derive general analytical expressions for the quantum Fisher information matrix and for the measurement compatibility condition, ensuring asymptotic saturability of the quantum Cram\'er-Rao bound, for the estimation of multiple parameters encoded in multimode Gaussian states. We then apply our results to the joint estimation of a phase shift and two parameters characterizing Gaussian phase covariant noise in optical interferometry. In such a scheme, we show that two-mode displaced squeezed input probes with optimally tuned squeezing and displacement fulfil the measurement compatibility condition and enable the simultaneous estimation of all three parameters, with an advantage over individual estimation schemes that quickly rises with increasing mean energy of the probes.
Cite
@article{arxiv.1711.09132,
title = {Multiparameter Gaussian Quantum Metrology},
author = {Rosanna Nichols and Pietro Liuzzo-Scorpo and Paul A. Knott and Gerardo Adesso},
journal= {arXiv preprint arXiv:1711.09132},
year = {2018}
}
Comments
14 pages, 3 figures; expanded and updated; to appear in Physical Review A