Bibliographies thématiques / Quantum estimation theory

Littérature scientifique sur le sujet « Quantum estimation theory »

Auteur : Grafiati
Publié le 10 mars 2023

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Articles de revues sur le sujet "Quantum estimation theory"

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Rodríguez-García, Marco A., Isaac Pérez Castillo et P. Barberis-Blostein. « Efficient qubit phase estimation using adaptive measurements ». Quantum 5 (4 juin 2021) : 467. http://dx.doi.org/10.22331/q-2021-06-04-467.

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Estimating correctly the quantum phase of a physical system is a central problem in quantum parameter estimation theory due to its wide range of applications from quantum metrology to cryptography. Ideally, the optimal quantum estimator is given by the so-called quantum Cramér-Rao bound, so any measurement strategy aims to obtain estimations as close as possible to it. However, more often than not, the current state-of-the-art methods to estimate quantum phases fail to reach this bound as they rely on maximum likelihood estimators of non-identifiable likelihood functions. In this work we thoroughly review various schemes for estimating the phase of a qubit, identifying the underlying problem which prohibits these methods to reach the quantum Cramér-Rao bound, and propose a new adaptive scheme based on covariant measurements to circumvent this problem. Our findings are carefully checked by Monte Carlo simulations, showing that the method we propose is both mathematically and experimentally more realistic and more efficient than the methods currently available.
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PARIS, MATTEO G. A. « QUANTUM ESTIMATION FOR QUANTUM TECHNOLOGY ». International Journal of Quantum Information 07, supp01 (janvier 2009) : 125–37. http://dx.doi.org/10.1142/s0219749909004839.

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Several quantities of interest in quantum information, including entanglement and purity, are nonlinear functions of the density matrix and cannot, even in principle, correspond to proper quantum observables. Any method aimed to determine the value of these quantities should resort to indirect measurements and thus corresponds to a parameter estimation problem whose solution, i.e. the determination of the most precise estimator, unavoidably involves an optimization procedure. We review local quantum estimation theory and present explicit formulas for the symmetric logarithmic derivative and the quantum Fisher information of relevant families of quantum states. Estimability of a parameter is defined in terms of the quantum signal-to-noise ratio and the number of measurements needed to achieve a given relative error. The connections between the optmization procedure and the geometry of quantum statistical models are discussed. Our analysis allows to quantify quantum noise in the measurements of non observable quantities and provides a tools for the characterization of signals and devices in quantum technology.
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Bakmou, Lahcen, Mohammed Daoud et Rachid ahl laamara. « Multiparameter quantum estimation theory in quantum Gaussian states ». Journal of Physics A : Mathematical and Theoretical 53, no 38 (26 août 2020) : 385301. http://dx.doi.org/10.1088/1751-8121/aba770.

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Gianani, Ilaria, et Claudia Benedetti. « Multiparameter estimation of continuous-time quantum walk Hamiltonians through machine learning ». AVS Quantum Science 5, no 1 (mars 2023) : 014405. http://dx.doi.org/10.1116/5.0137398.

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The characterization of the Hamiltonian parameters defining a quantum walk is of paramount importance when performing a variety of tasks, from quantum communication to computation. When dealing with physical implementations of quantum walks, the parameters themselves may not be directly accessible, and, thus, it is necessary to find alternative estimation strategies exploiting other observables. Here, we perform the multiparameter estimation of the Hamiltonian parameters characterizing a continuous-time quantum walk over a line graph with n-neighbor interactions using a deep neural network model fed with experimental probabilities at a given evolution time. We compare our results with the bounds derived from estimation theory and find that the neural network acts as a nearly optimal estimator both when the estimation of two or three parameters is performed.
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Suzuki, Jun. « Information Geometrical Characterization of Quantum Statistical Models in Quantum Estimation Theory ». Entropy 21, no 7 (18 juillet 2019) : 703. http://dx.doi.org/10.3390/e21070703.

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In this paper, we classify quantum statistical models based on their information geometric properties and the estimation error bound, known as the Holevo bound, into four different classes: classical, quasi-classical, D-invariant, and asymptotically classical models. We then characterize each model by several equivalent conditions and discuss their properties. This result enables us to explore the relationships among these four models as well as reveals the geometrical understanding of quantum statistical models. In particular, we show that each class of model can be identified by comparing quantum Fisher metrics and the properties of the tangent spaces of the quantum statistical model.
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Fujiwara, A. « Statistical estimation of a quantum operation ». Quantum Information and Computation 4, no 6&7 (décembre 2004) : 479–88. http://dx.doi.org/10.26421/qic4.6-7-7.

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Niu, Ming-Li, Yue-Ming Wang et Zhi-Jian Li. « Estimation of light-matter coupling constant under dispersive interaction based on quantum Fisher information ». Acta Physica Sinica 71, no 9 (2022) : 090601. http://dx.doi.org/10.7498/aps.71.20212029.

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Quantum parameter estimation is one of the most important applications in quantum metrology. The basic theory of quantum parameter estimation－quantum Cramer-Rao bound－shows that the precision limit of quantum parameter estimation is directly related to quantum Fisher information. Therefore quantum Fisher information is extremely important in the quantum parameter estimation. In this paper we use quantum parameter estimation theory to estimate the coupling constant of the Jaynes-Cummings model with large detuning. The initial probing state is the direct product state of qubit and radiation field in which Fock state, thermal state and coherent state are taken into account respectively. We calculate the quantum Fisher information of the hybrid system as well as qubit and radiation field for each probing state after the parameter evolution under the Hamiltonian of the Jaynes-Cummings model with large detuning. The results show that the quantum Fisher information increases monotonically with the average photon number increasing. The optimal detection state is that when the qubit system is in the equal weight superposition of the ground and the excited state, at this time the quantum Fisher information always reaches a maximum value, When the radiation field of probing state is Fock state or the thermal state, the information about the estimated parameter is included only in the qubit. The estimation accuracy of the coupling constant with thermal state or coherent state is higher than that with Fock state.
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Nogueira, Edson C., Gustavo de Souza, Adalberto D. Varizi et Marcos D. Sampaio. « Quantum estimation in neutrino oscillations ». International Journal of Quantum Information 15, no 06 (septembre 2017) : 1750045. http://dx.doi.org/10.1142/s0219749917500459.

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In this work, we analyze two-flavor neutrino oscillations within the framework of quantum estimation theory (QET). We compute the quantum Fischer information (QFI) for the mixing angle [Formula: see text] and show that mass measurements are the ones that achieve optimal precision. We also study the Fischer information (FI) associated with flavor measurements and show that they are optimized at specific neutrino times-of-flight. Therefore, although the usual population measurement does not realize the precision limit set by the QFI, it can in principle be implemented with the best possible sensitivity to [Formula: see text]. We investigate how these quantifiers relate to the single-particle, mode entanglement in neutrino oscillations. We demonstrate that this form of entanglement does not enhance either of them. In particular, our results show that in single-particle settings, entanglement is not directly connected with the enhancement of precision in metrological tasks.
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Streater, R. F. « Proof of a Modified Jaynes's Estimation Theory ». Open Systems & ; Information Dynamics 18, no 02 (juin 2011) : 223–33. http://dx.doi.org/10.1142/s1230161211000157.

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It is proved that the state of maximum entropy, having observed values for the n observables, X1,…,Xn, is the same state that minimises the matrix of covariances of any n locally unbiased estimators for n parameters for the probability distribution of X1,…,Xn. We sketch how to get a similar result in quantum theory, in which X1,…,Xn are (not necessarily commuting) quadratic forms that are bounded relative to a positive self-adjoint operator H such that exp (-βH) is of trace-class for some positive β.
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Haase, J. F., A. Smirne, S. F. Huelga, J. Kołodynski et R. Demkowicz-Dobrzanski. « Precision Limits in Quantum Metrology with Open Quantum Systems ». Quantum Measurements and Quantum Metrology 5, no 1 (1 août 2016) : 13–39. http://dx.doi.org/10.1515/qmetro-2018-0002.

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Abstract The laws of quantum mechanics allow to perform measurements whose precision supersedes results predicted by classical parameter estimation theory. That is, the precision bound imposed by the central limit theorem in the estimation of a broad class of parameters, like atomic frequencies in spectroscopy or external magnetic field in magnetometry, can be overcomewhen using quantum probes. Environmental noise, however, generally alters the ultimate precision that can be achieved in the estimation of an unknown parameter. This tutorial reviews recent theoretical work aimed at obtaining general precision bounds in the presence of an environment.We adopt a complementary approach,wherewe first analyze the problem within the general framework of describing the quantum systems in terms of quantum dynamical maps and then relate this abstract formalism to a microscopic description of the system’s dissipative time evolution.We will show that although some forms of noise do render quantum systems standard quantum limited, precision beyond classical bounds is still possible in the presence of different forms of local environmental fluctuations.
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Thèses sur le sujet "Quantum estimation theory"

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Kubitzki, Marcus. « State and Parameter Estimation in Quantum Theory ». [S.l. : s.n.], 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10806359.

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Ahmadi, Abhari Seyed Hamed. « Quantum Algorithms for : Quantum Phase Estimation, Approximation of the Tutte Polynomial and Black-box Structures ». Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5096.

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In this dissertation, we investigate three different problems in the field of Quantum computation. First, we discuss the quantum complexity of evaluating the Tutte polynomial of a planar graph. Furthermore, we devise a new quantum algorithm for approximating the phase of a unitary matrix. Finally, we provide quantum tools that can be utilized to extract the structure of black-box modules and algebras. While quantum phase estimation (QPE) is at the core of many quantum algorithms known to date, its physical implementation (algorithms based on quantum Fourier transform (QFT)) is highly constrained by the requirement of high-precision controlled phase shift operators, which remain difficult to realize. In the second part of this dissertation, we introduce an alternative approach to approximately implement QPE with arbitrary constant-precision controlled phase shift operators. The new quantum algorithm bridges the gap between QPE algorithms based on QFT and Kitaev's original approach. For approximating the eigenphase precise to the nth bit, Kitaev's original approach does not require any controlled phase shift operator. In contrast, QPE algorithms based on QFT or approximate QFT require controlled phase shift operators with precision of at least Pi/2n. The new approach fills the gap and requires only arbitrary constant-precision controlled phase shift operators. From a physical implementation viewpoint, the new algorithm outperforms Kitaev's approach. The other problem we investigate relates to approximating the Tutte polynomial. We show that the problem of approximately evaluating the Tutte polynomial of triangular graphs at the points (q,1/q) of the Tutte plane is BQP-complete for (most) roots of unity q. We also consider circular graphs and show that the problem of approximately evaluating the Tutte polynomial of these graphs at a point is DQC1-complete and at some points is in BQP. To show that these problems can be solved by a quantum computer, we rely on the relation of the Tutte polynomial of a planar G graph with the Jones and HOMFLY polynomial of the alternating link D(G) given by the medial graph of G. In the case of our graphs the corresponding links are equal to the plat and trace closures of braids. It is known how to evaluate the Jones and HOMFLY polynomial for closures of braids. To establish the hardness results, we use the property that the images of the generators of the braid group under the irreducible Jones-Wenzl representations of the Hecke algebra have finite order. We show that for each braid we can efficiently construct a braid such that the evaluation of the Jones and HOMFLY polynomials of their closures at a fixed root of unity leads to the same value and that the closures of the resulting braid are alternating links. The final part of the dissertation focuses on finding the structure of a black-box module or algebra. Suppose we are given black-box access to a finite module M or algebra over a finite ring R and a list of generators for M and R. We show how to find a linear basis and structure constants for M in quantum poly (log|M|) time. This generalizes a recent quantum algorithm of Arvind et al. which finds a basis representation for rings. We then show that our algorithm is a useful primitive allowing quantum computer to determine the structure of a finite associative algebra as a direct sum of simple algebras. Moreover, it solves a wide variety of problems regarding finite modules and rings. Although our quantum algorithm is based on Abelian Fourier transforms, it solves problems regarding the multiplicative structure of modules and algebras, which need not be commutative. Examples include finding the intersection and quotient of two modules, finding the additive and multiplicative identities in a module, computing the order of an module, solving linear equations over modules, deciding whether an ideal is maximal, finding annihilators, and testing the injectivity and surjectivity of ring homomorphisms. These problems appear to be exponentially hard classically.
ID: 031001318; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Title from PDF title page (viewed March 27, 2013).; Thesis (Ph.D.)--University of Central Florida, 2012.; Includes bibliographical references (p. 82-86).
Ph.D.
Doctorate
Mathematics
Sciences
Mathematics
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Porta, Mana Piero Giovanni Luca. « Studies in plausibility theory, with applications to physics ». Doctoral thesis, Kista : [Mikroelektronik och tillämpad fysik Microelectronics and Applied Physics, Kungliga Tekniska högskolan], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4421.

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Benedetti, C. « DECOHERENCE, NON-MARKOVIANITY AND QUANTUM ESTIMATION IN QUBIT SYSTEMS SUBJECT TO CLASSICAL NOISE ». Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/254031.

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The unavoidable interaction of a quantum system with its environment usually degrades its coherence and quantumness. The environment and the decoherence process may be described as the interaction with a classical or quantized bath. As a matter of fact, the classical description becomes progressively more reliable as far as the environment has many degrees of freedom, i.e. it becomes complex, or when the interaction between a quantum system and a classical fluctuating field is taken into account. In this thesis, I consider a qubit system coupled to a stochastic classical field and address the decoherence and non-Markovianity induced by the external noise as well as the spectral characterization of the classical field by quantum-limited measurement on the qubit. I thus analyze the dynamics of quantum correlations between two non-interacting, initially entangled qubits subject to a classical noise generated by a stochastic process. Two relevant classes of noise are taken into account: Gaussian noise, such as the Ornstein-Uhlenbeck process, and non-Gaussian noise, such as the random telgraph noise and the colored noise with 1/f spectrum. I also discuss the evaluation of non-Markovianity of the induced dynamical map and link the presence of revivals of quantum correlations with the information backflow to the system. The precise characterization of the stochastic process generating the classical noise, possibly using minimal resources, is a crucial ingredient for the design of high-precision measurements and reliable communication protocols. To this purpose, I also address the characterization of the spectral parameters of classical noise by quantum probes, e.g. a qubit coupled to the stochastic process generating the noise. By using the tools of quantum estimation theory, I explore the performances of quantum measurements on the qubit and show that it is possible to effectively extract information about the noise.
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Knee, George C. « Concepts and applications of quantum measurement ». Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2838a30b-302c-4fac-9e86-1ca452a88a83.

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In this thesis I discuss the nature of ‘measurement’ in quantum theory. ‘Measurement’ is associated with several different processes: the gradual imprinting of information about one system onto another, which is well understood; the collapse of the wavefunction, which is ill-defined and troublesome; and finally, the means by which inferences about unknown experimental parameters are made. I present a theoretical extension to an experimental proposal from Leggett and Garg, who suggested that the quantum-or-classical reality of a macroscopic system may be probed with successive measurements arrayed in time. The extension allows for a finite level of imperfection in the protocol, and makes use of Leggett’s ‘null result’ measurement scheme. I present the results of an experiment conducted in Oxford that, up to certain loopholes, defies a non-quantum interpretation of the dynamics of phosphorous nuclei embedded in silicon. I also present the theory of statistical parameter estimation, and discover that a recent trend to employ time symmetric ‘postselected’ measurements offers no true advantage over standard methods. The technique, known as weak-value amplification, combines a weak transfer of quantum information from system to meter with conditional data rejection, to surprising effect. The Fisher information is a powerful tool for evaluating the performance of any parameter estimation model, and it reveals the technique to be worse than ordinary, preselected only measurements. That this is true despite the presence of noise (including magnetic field fluctuations causing deco- herence, poor resolution detection, and random displacements), casts serious doubt on the utility of the method.
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Souza, Douglas Delgado de 1987. « Informação quântica com estados coerentes comprimidos da luz ». [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276940.

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Orientador: Antonio Vidiella Barranco
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-28T00:18:27Z (GMT). No. of bitstreams: 1 Souza_DouglasDelgadode_D.pdf: 6011689 bytes, checksum: b920d0dfb23c23b599d6bf1a254285ec (MD5) Previous issue date: 2015
Resumo: Na primeira parte deste trabalho seguimos os estudos de Hirota e colaboradores e definimos quatro estados quase-Bell baseados em estados coerentes comprimidos da luz. Dois desses estados são maximamente emaranhados, enquanto o emaranhamento dos outros dois depende apenas da sobreposição entre os estados coerentes comprimidos que os compõem. A partir destes estados quase-Bell, definimos novos estados interpolados cujo emaranhamento é também governado por um parâmetro de interpolação adicional e estudamos algumas das propriedades destes estados (emaranhamento e eficiência energética). Por fim, usamos estes estados e definimos alguns estados de Werner, com os quais analisamos de forma simples uma possível influência de um ambiente dissipativo parametrizado pela probabilidade de o estado de Werner estar em sua forma emaranhada ou misturada. Para esta análise usamos os conceitos de separabilidade e emaranhamento. Na segunda parte estudamos a estimativa de fase quântica usando estados gaussianos puros (estados coerentes comprimidos). Iniciamos com a estimativa da fase introduzida por um operador unitário em cujo hamiltoniano está presente uma perturbação linear nos operadores de criação e aniquilação, além do operador de número de fótons responsável pela evolução de fase (perturbação linear unitária). Obtemos quais são os estados gaussianos ótimos para a estimativa desta fase e analisamos a optimalidade da detecção homódina. A seguir, consideramos o parâmetro de perturbação como uma variável aleatória que obedece a uma distribuição gaussiana de probabilidades (perturbação linear aleatória) e novamente obtemos os estados de sonda ótimos e analisamos a optimalidade da detecção homódina. Por fim, estudamos a estimativa de fase com perturbação linear unitária utilizando os estados quase-Bell interpolados definidos na primeira parte deste trabalho e verificamos que a utilização de emaranhamento permite uma melhor estimativa de fase para uma mesma energia disponível
Abstract: In the first part of this work we follow the studies of Hirota and collaborators and we define four quasi-Bell states based on squeezed coherent states of light. Two of these states are maximally entangled, while the entanglement of the other two depends only on the overlap between the squeezed coherent states that were combined. From these quasi-Bell states we define new interpolated states for which the entanglement is also governed by an additional interpolation parameter, and we study some of the properties of these states (entanglement and energy efficiency). Finally, we use these states to define some Werner states, which we use to study in a simple way the possible influence of some dissipative environment parameterized by the probability that the Werner state is entangled or mixed. For this analysis we use the concepts of separability and entanglement. In the second part, we study the quantum phase estimation using pure Gaussian states (squeezed coherent states). We begin with the estimation of the phase introduced by a unitary operator whose Hamiltonian also contains a disturbance that is linear in the creation and annihilation operators in addition to the photon number operator responsible for the phase evolution (unitary linear disturbance). We find what are the optimal Gaussian states for this phase estimation and we also analyze the optimality of the homodyne detection. Next, we consider the disturbance parameter to be a random variable submitted to a Gaussian distribution (random linear disturbance) and again we find what are the optimal probe states and analyze the optimality of the homodyne detection. Finally we study the phase estimation with unitary linear disturbance using the interpolated quasi-Bell states defined in the first part of this work and we verify that the use of entanglement leads to a better phase estimation for the same amount of available energy
Doutorado
Física
Doutor em Ciências
2011/00220-5
FAPESP
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Baldasare, Corey Adam. « Quantum Chemical pKa Estimation of Carbon Acids, Saturated Alcohols, and Ketones via Quantitative Structure-Activity Relationships ». Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1598550823525731.

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Santos, Jader Pereira dos. « Uso de luz quantizada para controle e medida em sistemas atômicos e moleculares ». reponame:Repositório Institucional da UFABC, 2015.

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Orientador: Prof. Dr.Fernando Luis Semião da Silva
Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, 2015.
A presente tese de doutorado tem como principal objetivo empregar luz quantizada para o controle e medida em sistemas complexos como em um conjunto de cromóforos, e em um condensado de Bose-Einstein. Em especial, desenvolvemos formalismos de pulsos e equações mestras aplicáveis a esses sistemas e utilizamos teoria de estimativa quântica para determinar quantidades atômicas relevantes de maneira indireta (medindo propriedades da luz). Também empregamos técnicas variadas para obtenção de equações mestras para estudar diferentes problemas envolvendo interação de luz quântica com matéria. Em um caso, obtivemos uma equação mestra microscópica para o estudo de dois sistemas de dois níveis acoplados no espaço livre, e mostramos como a equação mestra microscópica desse sistema se distingue de equações fenomenológicas para o mesmo. Por fim, também discutimos a obtenção de uma equação mestra para o estudo de transferência de emaranhamento entre o campo eletromagnético quantizado e complexos Fenna-Matthews-Olson localizados em cavidades óticas distintas.
The main aim of the present Ph.D. thesis is to employ quantized light to control and measurement of complex systems such as a set of chromophores and a Bose- Einstein condensate in a double well. Specifically, we develop a formalism for pulses and master equations that can be applied to those systems and use quantum estimation theory to get information on relevant parameters in atomic system in a indirect way (measuring light properties). We also employ varied techniques for the obtention of master equations to study different problems involving the interaction of quantum light and matter. We obtained a microscopic master equation for the study of two coupled two-level systems in the free space, and we showed how the microscopic master equation of this system distinguish from the phenomenological ones. Finally, we also discuss the obtention of a master equation for the study of the transference of entanglement between the quantized electromagnetic field and the Fenna-Matthews-Olson complex localized in distinct optical cavities.
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Silva, Domingos José Lopes da. « Estatística de extremos : limites da performance humana - estudo com lançadores e saltadores do atletismo ». Doctoral thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/28600.

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Eventos extremos são raros, mas quando ocorrem têm um enorme impacto social e uma atenção mediática considerável. São exemplo os recordes no mundo do desporto – raros de acontecerem, mas quando ocorrem não apenas são divulgados nos mais variados meios de comunicação social, como são motivo de modificação da metodologia de treino e do comportamento do atleta. Como prever esta ocorrência? Qual a probabilidade de ocorrência? Qual a magnitude da ocorrência? Quanto tempo de espera? A teoria de valores extremos, baseada no teorema dos tipos extremais de Fisher-Tippett- Gnedenko, proporciona um rigoroso quadro de análise dos valores extremos, estimando a probabilidade de ocorrência de eventos que estão para além da amostra disponível. Assim, sob a questão “qual o limite da performance humana?”, este trabalho no domínio da Estatística de Extremos tem aplicações ao desporto de alto rendimento, particularmente às especialidades de lançamentos e saltos do atletismo. Foram utilizadas as metodologias: (i) r-maiores observações, (ii) excessos acima de um limiar, e (iii) máximos de blocos não-estacionários. Decidida a distribuição limite do máximo associado ao evento em estudo e o modelo que melhor se adequa aos dados disponíveis, a estimação pontual dos parâmetros extremais foi realizada por máxima verosimilhança e a estimação intervalar pelo método delta e pela função profile log-likelihood. Em cada método foram testados diversos modelos. Recorremos a técnicas gráficas, estabilidade dos erros-padrão, intervalos de confiança, testes de hipóteses e algumas métricas de erro, para verificação do ajustamento dos modelos aos dados disponíveis. Estamos particularmente interessados na estimação de quantis extremais, probabilidades de excedência, limite superior do suporte, níveis de retorno e período de retorno. Os resultados mostram que nos lançamentos do martelo, disco e dardo feminino existe uma forte probabilidade de se conseguir um novo recorde do mundo e que nos lançamentos masculinos tal probabilidade é reduzida. Com exceção do triplo-salto, nas restantes especialidades de saltos, o período de retorno (i.e., número de máximos individuais) até à ocorrência de um novo recorde do mundo é menor nas mulheres do que nos homens; ABSTRACT: Statistics of Extremes: limits of human performance - study with throwers and jumpers in athletics Extreme events are rare, but when they do occur, they have an enormous social impact and they receive a considerable media attention. Such is the case of world records in sport – they rarely happen, but when they do, not only are they disclosed by all media, but they also cause changes in the training methodology and in the athlete's behaviour. How to predict this occurrence? What is the probability of occurrence? What is the magnitude of the occurrence? How long is the wait? The extreme value theory, based on the Fisher-Tippett-Gnedenko theorem, provides a rigorous framework for analysing extreme values, estimating the probability of the occurrence of events that are beyond the sample. Thus, research within the area of Extreme Statistics provide information to answer the question “what is the limit of human performance?” in the framework of high-performance sport, particularly in the case of the specialties of throwing and jumping in athletics. The methodologies used were: (i) r-largest order statistics, (ii) peaks over threshold, and (iii) non-stationary annual maximum. Once decided the limit distribution of the maximum associated with the event under study and the model that best fits the available data, the point estimation of the extremal parameters were performed by maximum likelihood estimation, with Nelder- Mead or BFGS optimization and the interval estimation using the delta method and the profile loglikelihood function. In each method, several models were tested. We used graphical techniques, stability of standard errors, confidence intervals, hypothesis tests and some error metrics, to verify if the models fit the available data. We were particularly interested in the estimation of extreme quantiles, exceedance probability, right endpoint, return levels and return period. The results suggest that in hammer, discus and javelin throwing there are a strong probability of a new world record will be achieved. In the case of male, throwing events, the forecast of a new world record being achieved with reduced probability. With exception of triple-jump, in all other jumping specialities, the return period (i.e., number of individual maximums) until the occurrence of a new world record is shorter in women than in men.
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Gherardini, Stefano. « Noise as a resource - Probing and manipulating classical and quantum dynamical systems via stochastic measurements ». Doctoral thesis, 2018. http://hdl.handle.net/2158/1120060.

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In this thesis, common features from the theories of open quantum systems, estimation of state dynamics and statistical mechanics have been integrated in a comprehensive framework, with the aim to analyze and quantify the energetic and information contents that can be extracted from a dynamical system subject to the external environment. The latter is usually assumed to be deleterious for the feasibility of specic control tasks, since it can be responsible for uncontrolled time-dependent (and even discontinuous) changes of the system. However, if the effects of the random interaction with a noisy environment are properly modeled by the introduction of a given stochasticity within the dynamics of the system, then even noise contributions might be seen as control knobs. As a matter of fact, even a partial knowledge of the environment can allow to set the system in a dynamical condition in which the response is optimized by the presence of noise sources. In particular, we have investigated what kind of measurement devices can work better in noisy dynamical regimes and studied how to maximize the resultant information via the adoption of estimation algorithms. Moreover, we have shown the optimal interplay between quantum dynamics, environmental noise and complex network topology in maximizing the energy transport efficiency. Then, foundational scientic aspects, such as the occurrence of an ergodic property for the system-environment interaction modes of a randomly perturbed quantum system or the characterization of the stochastic quantum Zeno phenomena, have been analyzed by using the predictions of the large deviation theory. Finally, the energy cost in maintaining the system in the non-equilibrium regime due to the presence of the environment is evaluated by reconstructing the corresponding thermodynamics entropy production. In conclusion, the present thesis can constitute the basis for an effective resource theory of noise, which is given by properly engineering the interaction between a dynamical (quantum or classical) system and its external environment.
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Livres sur le sujet "Quantum estimation theory"

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Matteo, Paris, et Řeháček Jaroslav, dir. Quantum state estimation. Berlin : Springer, 2004.

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Harney, Hanns L. Bayesian Inference : Parameter Estimation and Decisions. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003.

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Watanabe, Yu. Formulation of Uncertainty Relation Between Error and Disturbance in Quantum Measurement by Using Quantum Estimation Theory. Tokyo : Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54493-7.

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Harney, Hanns L. Bayesian inference : Parameter estimation and decisions. Berlin : Springer, 2002.

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1975-, Sims Robert, et Ueltschi Daniel 1969-, dir. Entropy and the quantum II : Arizona School of Analysis with Applications, March 15-19, 2010, University of Arizona. Providence, R.I : American Mathematical Society, 2011.

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Barnett, Alex, 1972 December 7- editor of compilation, dir. Spectral geometry. Providence, Rhode Islands : American Mathematical Society, 2012.

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Paris, Matteo. Quantum State Estimation. Springer, 2010.

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Chakrabarti, Raj. Quantum Control and Quantum Estimation Theory. Taylor & Francis Group, 2011.

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Chakrabarti, Raj. Quantum Control and Quantum Estimation Theory. Taylor & Francis Group, 2021.

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Teo, Yong Siah. Introduction to Quantum-State Estimation. World Scientific Publishing Co Pte Ltd, 2015.

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Chapitres de livres sur le sujet "Quantum estimation theory"

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Watanabe, Yu. « Quantum Estimation Theory ». Dans Formulation of Uncertainty Relation Between Error and Disturbance in Quantum Measurement by Using Quantum Estimation Theory, 37–44. Tokyo : Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54493-7_4.

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Hayashi, Masahito. « Quantum Information Geometry and Quantum Estimation ». Dans Quantum Information Theory, 253–322. Berlin, Heidelberg : Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49725-8_6.

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Watanabe, Yu. « Classical Estimation Theory ». Dans Formulation of Uncertainty Relation Between Error and Disturbance in Quantum Measurement by Using Quantum Estimation Theory, 19–36. Tokyo : Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54493-7_3.

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Hayashi, Masahito. « Information Quantities and Parameter Estimation in Classical Systems ». Dans Quantum Information Theory, 25–94. Berlin, Heidelberg : Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49725-8_2.

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D’ariano, G. M. « Quantum Estimation Theory and Optical Detection ». Dans Quantum Optics and the Spectroscopy of Solids, 139–74. Dordrecht : Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-015-8796-9_8.

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Chiribella, Giulio. « On Quantum Estimation, Quantum Cloning and Finite Quantum de Finetti Theorems ». Dans Theory of Quantum Computation, Communication, and Cryptography, 9–25. Berlin, Heidelberg : Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-18073-6_2.

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Kunihiro, Noboru. « Quantum Factoring Algorithm : Resource Estimation and Survey of Experiments ». Dans International Symposium on Mathematics, Quantum Theory, and Cryptography, 39–55. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5191-8_7.

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Abstract It is known that Shor’s algorithm can break many cryptosystems such as RSA encryption, provided that large-scale quantum computers are realized. Thus far, several experiments for the factorization of the small composites such as 15 and 21 have been conducted using small-scale quantum computers. In this study, we investigate the details of quantum circuits used in several factoring experiments. We then indicate that some of the circuits have been constructed under the condition that the order of an element modulo a target composite is known in advance. Because the order must be unknown in the experiments, they are inappropriate for designing the quantum circuit of Shor’s factoring algorithm. We also indicate that the circuits used in the other experiments are constructed by relying considerably on the target composite number to be factorized.
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Woodhead, Erik, Charles Ci Wen Lim et Stefano Pironio. « Semi-device-independent QKD Based on BB84 and a CHSH-Type Estimation ». Dans Theory of Quantum Computation, Communication, and Cryptography, 107–15. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-35656-8_9.

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Marvian, Iman, et Robert W. Spekkens. « Applying a Generalization of Schur-Weyl Duality to Problems in Quantum Information and Estimation ». Dans Theory of Quantum Computation, Communication, and Cryptography, 141–52. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-35656-8_12.

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Fujii, Tomohiro, et Masao Hirokawa. « A Data Concealing Technique with Random Noise Disturbance and a Restoring Technique for the Concealed Data by Stochastic Process Estimation ». Dans International Symposium on Mathematics, Quantum Theory, and Cryptography, 103–24. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5191-8_11.

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Abstract We propose a technique to conceal data on a physical layer by disturbing them with some random noises, and moreover, a technique to restore the concealed data to the original ones by using the stochastic process estimation. Our concealing-restoring system manages the data on the physical layer from the data link layer. In addition to these proposals, we show the simulation result and some applications of our concealing-restoring technique.
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Actes de conférences sur le sujet "Quantum estimation theory"

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Walter, Michael, et Joseph M. Renes. « A Heisenberg limit for quantum region estimation ». Dans 2014 IEEE International Symposium on Information Theory (ISIT). IEEE, 2014. http://dx.doi.org/10.1109/isit.2014.6875008.

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Pereg, Uzi. « Communication over Quantum Channels with Parameter Estimation ». Dans 2020 IEEE International Symposium on Information Theory (ISIT). IEEE, 2020. http://dx.doi.org/10.1109/isit44484.2020.9174144.

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Nair, Ranjith. « Quantum limits on optical phase estimation accuracy from classical rate-distortion theory ». Dans INTERNATIONAL CONFERENCE ON QUANTITATIVE SCIENCES AND ITS APPLICATIONS (ICOQSIA 2014) : Proceedings of the 3rd International Conference on Quantitative Sciences and Its Applications. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4903098.

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Ambainis, Andris, et Martins Kokainis. « Quantum algorithm for tree size estimation, with applications to backtracking and 2-player games ». Dans STOC '17 : Symposium on Theory of Computing. New York, NY, USA : ACM, 2017. http://dx.doi.org/10.1145/3055399.3055444.

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Gangopadhyay, Bijan Kumar. « Estimation of nanocluster separation limit to retain magnetic ordering using quantum theory of ferromagnetism ». Dans 2ND INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC 2017). Author(s), 2018. http://dx.doi.org/10.1063/1.5033136.

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Shepard, S. R., et Jeffrey H. Shapiro. « Ultimate quantum limits on phase measurement ». Dans OSA Annual Meeting. Washington, D.C. : Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oam.1988.ma5.

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In a shot-noise-limited (coherent state) phasesensing interferometer, the root-mean-square (rms) phase error is ~ 1 / N av 1 / 2 where Nav is the average number of detected photons. In an optimized squeezed-state interferometer, the rms phase error goes as 1/Nav. We have considered the phase measurement problem from the viewpoint of quantum estimation theory.1 In particular, for the problem of optimum phase-shift estimation from observation of a single mode of the radiation field under an average photon number constraint, we have found both the optimum quantum state and the optimum quantum measurement. The former turns out to have a truncated number-state expansion whose coefficients, out to the truncation point, fall off as 1/n. The latter turns out to be the Susskind-Glogower phase operator. More important, the resulting phase estimation performance improves as 1 / N av 2 .
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Frieden, B. Roy. « Restoration of Photon-Limited Images ». Dans Quantum-Limited Imaging and Image Processing. Washington, D.C. : Optica Publishing Group, 1986. http://dx.doi.org/10.1364/qlip.1986.wb1.

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Modern image detectors have attained the ultimate in sensitivity, enabling single-photon events to be seen. An array of such detectors may be used to form a "photon count" image, such as on the left in Fig. 1. If such a photo also suffers from blur, how well can it be restored to the ideal object on the right? We shall take a Bayesian1 view and seek the maximum probable (m.a.p.) and mean probable (m.m.s.e.) estimates of the object. This approach marries the known physics of photon image formation to estimation theory, a match which the Rev. Thomas Bayes himself might have blessed. As will be seen, it allows ultimate questions to be asked on object structure, even in cases of severe photon depletion.
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Oyewande, Oluwole E. « Towards an Estimation of PCEs from Surface Sputtering Parameters. » Dans 27th iSTEAMS-ACity-IEEE International Conference. Society for Multidisciplinary and Advanced Research Techniques - Creative Research Publishers, 2021. http://dx.doi.org/10.22624/aims/isteams-2021/v27p7.

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The advent of metal halide perovskites has revolutionised photovoltaic industries owing to their excellent optoelectronic properties and high power conversion efficiency (PCE) of about 25.5%. In this study, Monte Carlo simulation of ion-beam surface sputtering was employed to study sputtering characteristics, such as ion range and sputter yield, of lead and tin perovskites along with other potential materials. This was done to explore the possibility of estimating the PCE of these materials from their surface sputtering characteristics. Since surface sputtering simulations using MC methods are relatively faster and much less computationally expensive than the current standard computational method of determination of PCE using quantum theory and its associated dynamical evolution equations. Results and comparison of the sputtering characteristics for these materials (lead and lead-substituted perovskites inclusive) are presented. For Pb and Sn perovskites, the results revealed similar sputtering characteristics of linear projection ion range with about 78° ion incidence exhibiting maximum sputter yield. The results also showed a correlation between sputter characteristics and PCE. Keywords: Solar cells; Ion-beam surface sputtering; Perovskites; Sputter yield; Range of ions.
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Snyder, Donald L., et Timothy J. Schulz. « Some new methods for restoring images of faint objects ». Dans OSA Annual Meeting. Washington, D.C. : Optica Publishing Group, 1991. http://dx.doi.org/10.1364/oam.1991.ft1.

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New methods are reviewed for forming images of faint objects. Camera data are modeled as a doubly stochastic Poisson process to account for quantum limitations and apparent jitter from propagation of light through weak turbulence, camera vibration, and tracking errors. The new methods fall into two categories depending on the model that can be assumed for the jitter. An approach that generalizes the Richardson-Lucy iteration for image restoration from quantum-limited data is obtained via statistical estimation theory when a stochastic model for the jitter is available. Faint-object (i.e., quantum-limited) and bright-object alternatives to the phase retrieval methods of Fienup for second-order correlation data and of Weigelt for third-order correlation data are obtained when the jitter is assumed to be piecewise constant during snapshots of the object.
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Soffer, Bernard H., et Ryoichi Kikuchi. « Quantum Statistics Basis for Maximum Entropy Restoration ». Dans Quantum-Limited Imaging and Image Processing. Washington, D.C. : Optica Publishing Group, 1986. http://dx.doi.org/10.1364/qlip.1986.wa2.

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Maximum Entropy (ME) estimation has been applied in various forms with various names to a wide variety of problems ranging from the depths of seismic spectral analysis, sonar and radar beam forming and filter formation, to astronomical imaging and beyond to economics. The particular techniques and theoretical points of view differ greatly among the several disciplines. Our very general interpretation, which includes these others as special cases, is based on two considerations. Any image, measured as signal, pattern or spectrum, whatever it represents, is necessarily a degraded version of the true object because real measurement systems have limited spatial and temporal bandwidth. The samples are finite and perhaps undersampled. Furthermore noise cannot be ignored. Therefore, many different possible object patterns can produce the same measured image pattern. One way to resolve this ambiguity is to apply the ME method. In our interpretation, a probability is assigned to every possible object pattern and the most probable pattern is chosen as the estimated or restored object. Patterns are assigned probabilities based on the physics and statistics of the immediate problem. The entropy is understood to mean the logarithm of the probability, following Boltzmann. So, to find a maximum of the entropy is to find a maximum of the probability, subject to the measured image data constraints and any a priori bias. No new "principle of ME" or appeal to information theory is needed to justify the method, though they may enrich our understanding. Sometimes misunderstandings have arisen in the use of the information theoretic entropy of Shannon, –f log f, and it has been used inappropriately. These considerations have been developed at length,1 so only a brief summary will be given here. We develop the idea of ME in an analogy to the well known statistical mechanical principle of the minimization of free energy, and derive some useful benefits in the consideration of fluctuations or noise. The degree of confidence in the ME estimate is derived and some examples of the ME method are given showing super-resolution.
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Rapports d'organisations sur le sujet "Quantum estimation theory"

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Samuel, M. A. On estimating perturbative coefficients in quantum field theory and statistical physics. Office of Scientific and Technical Information (OSTI), mai 1994. http://dx.doi.org/10.2172/296832.

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Samuel, M. On Estimating Perturbative Coefficients in Quantum Field Theory and Statistical Physics. Office of Scientific and Technical Information (OSTI), novembre 2003. http://dx.doi.org/10.2172/826542.

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Samuel, Mark. Theorems on Estimating Perturbative Coefficients in Quantum Field Theory and Statistical Physics. Office of Scientific and Technical Information (OSTI), juin 2003. http://dx.doi.org/10.2172/813278.

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