Dynamical, thermal, and ground-state multiparameter quantum metrology: Fundamental limits and their attainability in magnetometry
Abstract
We consider the simultaneous estimation of multiple parameters in Hamiltonians of the form Hθ⃗= Hθ⃗P + HC, where Hθ⃗P encodes the unknown parameters and HC is a control term. We consider three basic paradigmatic frameworks for metrology: (i) dynamical, where the parameters are encoded unitarily, (ii) thermal, and (iii) ground state. We generalize previous bounds for single-parameter estimation to simultaneous multiparameter estimation for all three metrological settings and establish the conditions required for their saturability. We then focus on vector magnetometry, deriving tight bounds for the simultaneous estimation of magnetic-field components and identifying optimal many-body control Hamiltonians HC that saturate them. These results establish the fundamental limits of vector magnetometry for unitary dynamics, thermal equilibrium states, and ground states.
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BibTeX
@misc{pedroni2026dynamical,
title = {{Dynamical, thermal, and ground-state multiparameter quantum metrology: Fundamental limits and their attainability in magnetometry}},
author = {Riccardo Pedroni and Víctor Izquierdo and Advay Burte and Paolo Abiuso and John Calsamiglia and Martí Perarnau-Llobet},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.25977},
eprint = {2609.25977},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.25977},
}
RIS
TY - UNPB
TI - Dynamical, thermal, and ground-state multiparameter quantum metrology: Fundamental limits and their attainability in magnetometry
AU - Riccardo Pedroni
AU - Víctor Izquierdo
AU - Advay Burte
AU - Paolo Abiuso
AU - John Calsamiglia
AU - Martí Perarnau-Llobet
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.25977
UR - https://arxiv.org/abs/2609.25977
AB - We consider the simultaneous estimation of multiple parameters in Hamiltonians of the form H_θ⃗= H_θ⃗^P + H^C, where H_θ⃗^P encodes the unknown parameters and H^C is a control term. We consider three basic paradigmatic frameworks for metrology: (i) dynamical, where the parameters are encoded unitarily, (ii) thermal, and (iii) ground state. We generalize previous bounds for single-parameter estimation to simultaneous multiparameter estimation for all three metrological settings and establish the conditions required for their saturability. We then focus on vector magnetometry, deriving tight bounds for the simultaneous estimation of magnetic-field components and identifying optimal many-body control Hamiltonians H^C that saturate them. These results establish the fundamental limits of vector magnetometry for unitary dynamics, thermal equilibrium states, and ground states.
ER -