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Related papers: Parameter estimation with cluster states

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We compare the accuracy, precision and reliability of different methods for estimating key system parameters for two-level systems subject to Hamiltonian evolution and decoherence. It is demonstrated that the use of Bayesian modelling and…

Quantum Physics · Physics 2019-10-15 Sophie Schirmer , Frank Langbein

We investigate the phase sensitivity of a Mach-Zehnder interferometer using a special class of generalized coherent states constructed from generalized Heisenberg and deformed $su(1,1)$ algebras. These states, derived from a perturbed…

Quantum Physics · Physics 2025-11-03 N. E. Abouelkhir , A. Slaoui , R. Ahl Laamara

Influence of surrounding matter on the properties of clusters is considered by an approach combining the methods of statistical and quantum mechanics. A cluster is treated as a bound N-particle system and surrounding matter as thermostat.…

Statistical Mechanics · Physics 2015-06-25 V. I. Yukalov , E. P. Yukalova

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

A general decentralized computational framework for set-valued state estimation and prediction for the class of systems that accept a hybrid state machine representation is considered in this article. The decentralized scheme consists of a…

Systems and Control · Computer Science 2013-02-28 Naim Bajcinca , Yashar Kouhi , Vladislav Nenchev , Jörg Raisch

The concepts of separability, entanglement, spin-squeezing and Heisenberg limit are central in the theory of quantum enhanced metrology. In the current literature, these are well established only in the case of linear interferometers…

Quantum Physics · Physics 2013-05-29 P. Hyllus , L. Pezzé , A. Smerzi

Quantum metrology protocols allow to surpass precision limits typical to classical statistics. However, in recent years, no-go theorems have been formulated, which state that typical forms of uncorrelated noise can constrain the quantum…

Quantum Physics · Physics 2016-03-30 Andrea Smirne , Jan Kolodynski , Susana F. Huelga , Rafal Demkowicz-Dobrzanski

Identifying topological properties is a major challenge because, by definition, topological states do not have a local order parameter. While a generic solution to this challenge is not available yet, a broad class of topological states,…

Interferometric phase estimation is an essential tool for precise measurements of quantities such as displacement, velocity and material properties. The lower bound on measurement uncertainty achievable with classical resources is set by…

Quantum Physics · Physics 2024-07-23 Shakib Daryanoosh , Geoff J. Pryde , Howard M. Wiseman , Sergei Slussarenko

We investigate strategies for estimating a depolarizing channel for a finite dimensional system. Our analysis addresses the double optimization problem of selecting the best input probe state and the measurement strategy that minimizes the…

Quantum Physics · Physics 2009-11-07 Masahide Sasaki , Masashi Ban , Stephen M. Barnett

In this paper we do a detailed numerical investigation of the fault-tolerant threshold for optical cluster-state quantum computation. Our noise model allows both photon loss and depolarizing noise, as a general proxy for all types of local…

Quantum Physics · Physics 2009-11-13 Christopher M. Dawson , Henry L. Haselgrove , Michael A. Nielsen

Quantum Extreme Learning Machines (QELMs) have emerged as a potent tool for various quantum information processing tasks. We present a QELM protocol for estimating the amount of entanglement in Werner states. The protocol requires the…

Quantum Physics · Physics 2025-11-04 Hajar Assil , Abderrahim El Allati , Gian Luca Giorgi

Learning the Hamiltonian governing a quantum system is a central task in quantum metrology, sensing, and device characterization. Existing Heisenberg-limited Hamiltonian learning protocols either require multi-qubit operations that are…

Quantum Physics · Physics 2026-01-16 Shrigyan Brahmachari , Shuchen Zhu , Iman Marvian , Yu Tong

We show that it is possible to perform Heisenberg-limited metrology on GHZ-like states, in the presence of generic spatially local, possibly strong interactions during the measurement process. An explicit protocol, which relies on…

Quantum Physics · Physics 2024-04-03 Chao Yin , Andrew Lucas

Quantum discrimination and estimation are pivotal for many quantum technologies, and their performance depends on the optimal choice of probe state and measurement. Here we show that their performance can be further improved by suitably…

Quantum Physics · Physics 2020-09-14 Daniel Basilewitsch , Haidong Yuan , Christiane P. Koch

We derive a general criterion to detect entangled states in multi-partite systems based on the symmetric logarithmic derivative quantum Fisher information. This criterion is a direct consequence of the fact that separable states do not…

Quantum Physics · Physics 2016-10-12 Jun Suzuki

We address the experimental determination of entropic quantum discord for systems made of a pair of polarization qubits. We compare results from full and partial tomography and found that the two determinations are statistically compatible,…

We consider performing phase estimation under the following conditions: we are given only one copy of the input state, the input state does not have to be an eigenstate of the unitary, and the state must not be measured. Most quantum…

Quantum Physics · Physics 2022-12-13 Patrick Rall

Mapping the system evolution of a two-state system allows the determination of the effective system Hamiltonian directly. We show how this can be achieved even if the system is decohering appreciably over the observation time. A method to…

We introduce an experimental procedure for the detection of quantum entanglement of an unknown quantum state with as few measurements as possible. The method requires neither a priori knowledge of the state nor a shared reference frame…

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