Multiparameter quantum metrology in the Heisenberg Limit regime: many
repetition scenario vs. full optimization
- URL: http://arxiv.org/abs/2203.09541v3
- Date: Mon, 18 Jul 2022 10:30:29 GMT
- Title: Multiparameter quantum metrology in the Heisenberg Limit regime: many
repetition scenario vs. full optimization
- Authors: Wojciech G\'orecki, Rafa{\l} Demkowicz-Dobrza\'nski
- Abstract summary: We investigate the potential advantage of measuring all the parameter simultaneously compared to estimating them.
In particular, for the problem of magnetic field sensing using $N$ entangled spin-$1/2$, we show that the predictions based purely on the Cram'er-Rao formalism may be overly pessimistic.
The minimax approach reveals the superiority of measuring all the parameters jointly whereas the Cram'er-Rao approach indicates lack of such an advantage.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We discuss the Heisenberg limit in the multiparameter metrology within two
different paradigms -- the one, where the measurement is repeated many times
(so the Cram\'er-Rao bound is guaranteed to be asymptotically saturable) and
the second one, where all the resources are allocated into one experimental
realization (analyzed with the mimimax approach). We investigate the potential
advantage of measuring all the parameter simultaneously compared to estimating
them individually, while spending the same total amount of resources. We show
that in general the existence of such an advantage, its magnitude and
conditions under which it occurs depends on which of the two paradigms has been
chosen. In particular, for the problem of magnetic field sensing using $N$
entangled spin-$1/2$, we show that the predictions based purely on the
Cram\'er-Rao formalism may be overly pessimistic in this matter -- the minimax
approach reveals the superiority of measuring all the parameters jointly
whereas the Cram\'er-Rao approach indicates lack of such an advantage.
Related papers
- Multivariate root-n-consistent smoothing parameter free matching estimators and estimators of inverse density weighted expectations [51.000851088730684]
We develop novel modifications of nearest-neighbor and matching estimators which converge at the parametric $sqrt n $-rate.
We stress that our estimators do not involve nonparametric function estimators and in particular do not rely on sample-size dependent parameters smoothing.
arXiv Detail & Related papers (2024-07-11T13:28:34Z) - Multi-parameter quantum estimation of single- and two-mode pure Gaussian
states [0.0]
We derive the Holevo Cram'er-Rao bound (HCRB) for both displacement and squeezing parameter characterizing single and two-mode squeezed states.
In the single-mode scenario, we obtain an analytical bound and find that it degrades monotonically as the squeezing increases.
In the two-mode setting, the HCRB improves as the squeezing parameter grows and we show that it can be attained using double-homodyne detection.
arXiv Detail & Related papers (2024-03-06T18:29:17Z) - Theory of free fermions dynamics under partial post-selected monitoring [49.1574468325115]
We derive a partial post-selected Schrdinger"o equation based on a microscopic description of continuous weak measurement.
We show that the passage to the monitored universality occurs abruptly at finite partial post-selection.
Our approach establishes a way to study MiPTs for arbitrary subsets of quantum trajectories.
arXiv Detail & Related papers (2023-12-21T16:53:42Z) - Toward Incompatible Quantum Limits on Multiparameter Estimation [4.2043578689409475]
Heisenberg uncertainty principle prevents optimal measurements for incompatible parameters from being performed jointly.
A criterion proposed for multi parameter estimation provides a possible way to beat this curse.
A scheme involving high-order Hermite-Gaussian states as probes is proposed for estimating the spatial displacement and angular tilt of light.
arXiv Detail & Related papers (2023-10-11T01:24:03Z) - Quantum metrology in the finite-sample regime [0.6299766708197883]
In quantum metrology, the ultimate precision of estimating an unknown parameter is often stated in terms of the Cram'er-Rao bound.
We propose to quantify the quality of a protocol by the probability of obtaining an estimate with a given accuracy.
arXiv Detail & Related papers (2023-07-12T18:00:04Z) - Kernel-based off-policy estimation without overlap: Instance optimality
beyond semiparametric efficiency [53.90687548731265]
We study optimal procedures for estimating a linear functional based on observational data.
For any convex and symmetric function class $mathcalF$, we derive a non-asymptotic local minimax bound on the mean-squared error.
arXiv Detail & Related papers (2023-01-16T02:57:37Z) - Targeted Separation and Convergence with Kernel Discrepancies [61.973643031360254]
kernel-based discrepancy measures are required to (i) separate a target P from other probability measures or (ii) control weak convergence to P.
In this article we derive new sufficient and necessary conditions to ensure (i) and (ii)
For MMDs on separable metric spaces, we characterize those kernels that separate Bochner embeddable measures and introduce simple conditions for separating all measures with unbounded kernels.
arXiv Detail & Related papers (2022-09-26T16:41:16Z) - A unified view of likelihood ratio and reparameterization gradients [91.4645013545015]
We use a first principles approach to explain that LR and RP are alternative methods of keeping track of the movement of probability mass.
We show that the space of all possible estimators combining LR and RP can be completely parameterized by a flow field.
We prove that there cannot exist a single-sample estimator of this type outside our space, thus, clarifying where we should be searching for better Monte Carlo gradient estimators.
arXiv Detail & Related papers (2021-05-31T11:53:08Z) - Multiphase estimation without a reference mode [0.0]
We show that the absence of an external reference mode reduces the number of simultaneously estimatable parameters.
We also show that the symmetries of the parameters being estimated dictate the symmetries of the optimal probe states.
arXiv Detail & Related papers (2020-06-23T18:00:03Z) - Quantum enhanced metrology of Hamiltonian parameters beyond the
Cram\`er-Rao bound [0.0]
This tutorial focuses on developments in quantum parameter estimation beyond the Cramer-Rao bound.
It shows that an achievable bound to precision (beyond the Cramer-Rao) may be obtained in a closed form for the class of so-called controlled energy measurements.
arXiv Detail & Related papers (2020-03-05T08:35:40Z) - Generalized Sliced Distances for Probability Distributions [47.543990188697734]
We introduce a broad family of probability metrics, coined as Generalized Sliced Probability Metrics (GSPMs)
GSPMs are rooted in the generalized Radon transform and come with a unique geometric interpretation.
We consider GSPM-based gradient flows for generative modeling applications and show that under mild assumptions, the gradient flow converges to the global optimum.
arXiv Detail & Related papers (2020-02-28T04:18:00Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.