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Related papers: Lower Bounds for Quantum Parameter Estimation

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Adaptive techniques make practical many quantum measurements that would otherwise be beyond current laboratory capabilities. For example: they allow discrimination of nonorthogonal states with a probability of error equal to the Helstrom…

Quantum Physics · Physics 2009-12-15 H. M. Wiseman , D. W. Berry , S. D. Bartlett , B. L. Higgins , G. J. Pryde

The minimum accuracy heuristic evaluates quantum feature maps without requiring full quantum support vector machine (QSVM) training. However, the original formulation is computationally expensive, restricted to balanced datasets, and lacks…

We consider the problem of estimating the state of a large but finite number $N$ of identical quantum systems. In the limit of large $N$ the problem simplifies. In particular the only relevant measure of the quality of the estimation is the…

Quantum Physics · Physics 2008-12-18 R. D. Gill , S. Massar

Bounds on quantum probabilities and expectation values are derived for experimental setups associated with Bell-type inequalities. In analogy to the classical bounds, the quantum limits are experimentally testable and therefore serve as…

Quantum Physics · Physics 2007-05-23 Stefan Filipp , Karl Svozil

Achieving quantum-enhanced performances when measuring unknown quantities requires developing suitable methodologies for practical scenarios, that include noise and the availability of a limited amount of resources. Here, we report on the…

The quantum limit is a fundamental lower bound on the uncertainty when estimating a parameter in a system dominated by the minimum amount of noise (quantum noise). For the first time, we derive and demonstrate a quantum limit for…

Signal Processing · Electrical Eng. & Systems 2025-05-12 Huwei Wang , Roman Ermakov , Francesco Da Ros , Darko Zibar

The measurement of physical parameters is one of the main pillars of science. A classic example is the measurement of the optical phase enabled by optical interferometry where the best sensitivity achievable with N photons scales as 1/N -…

We address quantum estimation in situations where one has at disposal data from the measurement of an incomplete set of observables and some a priori information on the state itself. By expressing the a priori information in terms of a bias…

Quantum Physics · Physics 2009-11-13 Stefano Olivares , Matteo G. A. Paris

Optimal measurements for quantum multiparameter estimation are complicated by the uncertainty principle. Generally, there is a trade-off between the precision with which different parameters can be simultaneously estimated. The task of…

Quantum Physics · Physics 2025-11-20 Simon K. Yung , C. M. Yung , Lorcán O. Conlon , Syed M. Assad

Quantum hypothesis testing concerns the discrimination between quantum states. This paper introduces a novel lower bound for asymmetric quantum hypothesis testing that is based on the Nussbaum-Szko{\l}a mapping. The lower bound provides a…

Quantum Physics · Physics 2026-05-21 Jorge Lizarribar-Carrillo , Gonzalo Vazquez-Vilar , Tobias Koch

I propose quantum versions of the Ziv-Zakai bounds as alternatives to the widely used quantum Cram\'er-Rao bounds for quantum parameter estimation. From a simple form of the proposed bounds, I derive both a "Heisenberg" error limit that…

Quantum Physics · Physics 2012-06-07 Mankei Tsang

Quantification of coherence lies at the heart of quantum information processing and fundamental physics. Exact evaluation of coherence measures generally needs a full reconstruction of the density matrix, which becomes intractable for…

Quantum Physics · Physics 2021-06-28 Qi-Ming Ding , Xiao-Xu Fang , Xiao Yuan , Ting Zhang , He Lu

It is widely known that `collapse of the wave function' on a quantum system A may be brought about by an interaction with another quantum system B. We will prove that this is not just a possible, but a necessary consequence of information…

Quantum Physics · Physics 2007-05-23 Bas Janssens

The uncertainty principle lies at the heart of quantum mechanics, as it describes the fundamental trade-off between the precision of position and momentum measurements. In this work, we study the quantum particle in the Boltzmann states and…

Quantum Physics · Physics 2023-08-16 Yao Wang

Measurement is a fundamental notion in the usual approximate quantum mechanics of measured subsystems. Probabilities are predicted for the outcomes of measurements. State vectors evolve unitarily in between measurements and by reduction of…

General Relativity and Quantum Cosmology · Physics 2014-01-14 James B. Hartle

Measurements take a singular role in quantum theory. While they are often idealized as an instantaneous process, this is in conflict with all other physical processes in nature. In this Letter, we adopt a standpoint where the interaction…

Quantum Physics · Physics 2023-11-15 Nathan Shettell , Federico Centrone , Luis Pedro García-Pintos

Heisenberg scaling characterizes the ultimate precision of parameter estimation enabled by quantum mechanics, which represents an important quantum advantage of both theoretical and technological interest. Here, we study the attainability…

Quantum Physics · Physics 2022-04-26 Masahito Hayashi , Zi-Wen Liu , Haidong Yuan

In quantum mechanics, the Heisenberg uncertainty relation presents an ultimate limit to the precision by which one can predict the outcome of position and momentum measurements on a particle. Heisenberg explicitly stated this relation for…

Quantum Physics · Physics 2020-11-16 Han Bao , Shenchao Jin , Junlei Duan , Suotang Jia , Klaus Mølmer , Heng Shen , Yanhong Xiao

Quantum parameter estimation is central to many fields such as quantum computation, communications and metrology. Optimal estimation theory has been instrumental in achieving the best accuracy in quantum parameter estimation, which is…

Quantum Physics · Physics 2015-06-18 Shibdas Roy , Ian R. Petersen , Elanor H. Huntington

The Heisenberg uncertainty principle sets a lower bound on the sensitivity of continuous optical measurements of force. This bound, the standard quantum limit, can only be reached when a mechanical oscillator subjected to the force is…