Quantum Measurement

Autore: Vladimir B. Braginsky
Editore: Cambridge University Press
ISBN: 9780521484138
Grandezza: 74,57 MB
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This book is an up-to-date introduction to the quantum theory of measurement. Although the main principles of the field were elaborated in the 1930s by Bohr, Schrödinger, Heisenberg, von Neuman, and Mandelstam, it was not until the 1980s that technology became sufficiently advanced to allow its application in real experiments. Quantum measurement is now central to many ultra-high technology developments, such as "squeezed light," single atom traps, and searches for gravitational radiation. It is also considered to have great promise for computer science and engineering, particularly for its applications in information processing and transfer. The book begins with a brief introduction to the relevant theory and goes on to discuss all aspects of the design of practical quantum measurement systems.

Quantum Measurement And Control

Autore: Howard M. Wiseman
Editore: Cambridge University Press
ISBN: 0521804426
Grandezza: 52,37 MB
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Modern quantum measurement for graduate students and researchers in quantum information, quantum metrology, quantum control and related fields.

Quantum Measurement

Autore: Paul Busch
Editore: Springer
ISBN: 331943389X
Grandezza: 36,75 MB
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This is a book about the Hilbert space formulation of quantum mechanics and its measurement theory. It contains a synopsis of what became of the Mathematical Foundations of Quantum Mechanics since von Neumann’s classic treatise with this title. Fundamental non-classical features of quantum mechanics—indeterminacy and incompatibility of observables, unavoidable measurement disturbance, entanglement, nonlocality—are explicated and analysed using the tools of operational quantum theory. The book is divided into four parts: 1. Mathematics provides a systematic exposition of the Hilbert space and operator theoretic tools and relevant measure and integration theory leading to the Naimark and Stinespring dilation theorems; 2. Elements develops the basic concepts of quantum mechanics and measurement theory with a focus on the notion of approximate joint measurability; 3. Realisations offers in-depth studies of the fundamental observables of quantum mechanics and some of their measurement implementations; and 4. Foundations discusses a selection of foundational topics (quantum-classical contrast, Bell nonlocality, measurement limitations, measurement problem, operational axioms) from a measurement theoretic perspective. The book is addressed to physicists, mathematicians and philosophers of physics with an interest in the mathematical and conceptual foundations of quantum physics, specifically from the perspective of measurement theory.

Quantum Measurements And Decoherence

Autore: M. Mensky
Editore: Springer Science & Business Media
ISBN: 9401595666
Grandezza: 78,98 MB
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Quantum measurement (Le., a measurement which is sufficiently precise for quantum effects to be essential) was always one of the most impor tant points in quantum mechanics because it most evidently revealed the difference between quantum and classical physics. Now quantum measure ment is again under active investigation, first of all because of the practical necessity of dealing with highly precise and complicated measurements. The nature of quantum measurement has become understood much bet ter during this new period of activity, the understanding being expressed by the concept of decoherence. This term means a physical process lead ing from a pure quantum state (wave function) of the system prior to the measurement to its state after the measurement which includes classical elements. More concretely, decoherence occurs as a result of the entangle ment of the measured system with its environment and results in the loss of phase relations between components of the wave function of the measured system. Decoherence is essentially nothing else than quantum measurement, but considered from the point of view of its physical mechanism and resolved in time. The present book is devoted to the two concepts of quantum measure ment and decoherence and to their interrelation, especially in the context of continuous quantum measurement.

Quantum Measurement

Autore: Richard Healey
Editore: U of Minnesota Press
ISBN: 9780816630653
Grandezza: 27,74 MB
Formato: PDF
Vista: 6450
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Together with relativity theory, quantum mechanics stands as the conceptual foundation of modern physics. It forms the basis by which we understand the minute workings of the subatomic world. But at its core lies a paradox--it is unmeasurable. This book presents a powerful and energetic new approach to the measurement dilemma.

Quantum Measurement Theory And Its Applications

Autore: Kurt Jacobs
Editore: Cambridge University Press
ISBN: 1139992198
Grandezza: 24,25 MB
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Vista: 3644
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Recent experimental advances in the control of quantum superconducting circuits, nano-mechanical resonators and photonic crystals has meant that quantum measurement theory is now an indispensable part of the modelling and design of experimental technologies. This book, aimed at graduate students and researchers in physics, gives a thorough introduction to the basic theory of quantum measurement and many of its important modern applications. Measurement and control is explicitly treated in superconducting circuits and optical and opto-mechanical systems, and methods for deriving the Hamiltonians of superconducting circuits are introduced in detail. Further applications covered include feedback control, metrology, open systems and thermal environments, Maxwell's demon, and the quantum-to-classical transition.

Relativistic Quantum Measurement And Decoherence

Autore: Heinz-Peter Breuer
Editore: Springer
ISBN: 3540453695
Grandezza: 41,35 MB
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The Quantum Measurement Problem

Autore: Michael Steiner
Editore:
ISBN: 9781732291003
Grandezza: 72,44 MB
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Vista: 8613
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The Quantum Measurement Problem (QMP) is a single resource for information on the QMP and it establishes a basis for research on what is arguably the most well-known and still-unresolved scientific problem: how does our observed world relate to the quantum? The book is suitable for both undergraduate level study on a selective basis as well as graduate level study and for use as a resource for research scientists interested in aspects of the QMP. There are many sections that can even be profitably read by the general public to appreciate the history and future importance of the QMP. Although many books are now available that adequately address Quantum Information, this is the first book offering a comparable treatment for the QMP. The QMP has a companion website, https: //theqmp.com, with video presentations and other resources. There are some in the physics community that view the QMP only as a problem that requires an interpretation while others view its solution as essential to complete our physical description of the world and enhance our ability to design experimental probes of its physical elements in terms of quantum physics. This book critically examines these two viewpoints and resolves this dichotomy in favor of the latter viewpoint. The problem is precisely defined in terms of experimental operations and the scientific requirements that a resolution would have to meet. It explains why the QMP is a physical problem that requires more than an interpretation for its resolution and why a solution could have profound implications for physics as well as other fields. In particular, it uses quantum information methods for a constructive demonstration that unitary Schrödinger processes can be experimentally distinguished from measurement processes using well-established techniques such as Bell measurements, which would establish that measurement is a non-unitary process. Neither Schrödinger's equation nor the measurement postulate is found to be sufficient to explain measurement. For the first time, The QMP offers a single resource that thoroughly assesses the strengths and weaknesses of the major approaches to the QMP. . The exposition in The QMP contains eight chapters, including problem sets, with dual tracks throughout the book that allow both those with a technical background in quantum physics or quantum information as well as less-technical readers to come up to speed on the QMP, depending on their interests and background. . Chapters 1 and 2 are an introductory-level presentation of wave-particle duality and unitary Schrödinger processes. Chapter 3 is a key chapter that uses quantum information methods for a constructive demonstration that unitary Schrödinger processes can be experimentally distinguished from measurement processes using well-established techniques such as Bell measurements, which would establish that measurement is a non-unitary process. Chapter 4 presents a detailed definition of the QMP in terms of experimental observations and uses the results of Chapter 3 to systematically evaluate the strength and weaknesses of all the major approaches to the QMP in the literature and determine which constitute physical theories as opposed to philosophical interpretations. Chapter 5 gives an uncensored historical perspective leading to the development of quantum physics from the viewpoint of those physical aspects which will ultimately form the elements of the QMP. Chapter 6 presents a unique discussion of the Scientific Method and how the use of scientific deduction within the approach of radical conservatism can most proficiently address problems of quantum foundations. Chapter 7 presents concepts and mathematical tools useful for further research developments of both closed and open system approaches to the QMP. Chapter 8 presents conclusions and the status of the QMP for moving forward.

Formulation Of Uncertainty Relation Between Error And Disturbance In Quantum Measurement By Using Quantum Estimation Theory

Autore: Yu Watanabe
Editore: Springer Science & Business Media
ISBN: 4431544933
Grandezza: 23,73 MB
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Vista: 9510
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In this thesis, quantum estimation theory is applied to investigate uncertainty relations between error and disturbance in quantum measurement. The author argues that the best solution for clarifying the attainable bound of the error and disturbance is to invoke the estimation process from the measurement outcomes such as signals from a photodetector in a quantum optical system. The error and disturbance in terms of the Fisher information content have been successfully formulated and provide the upper bound of the accuracy of the estimation. Moreover, the attainable bound of the error and disturbance in quantum measurement has been derived. The obtained bound is determined for the first time by the quantum fluctuations and correlation functions of the observables, which characterize the non-classical fluctuation of the observables. The result provides the upper bound of our knowledge obtained by quantum measurements. The method developed in this thesis will be applied to a broad class of problems related to quantum measurement to build a next-generation clock standard and to successfully detect gravitational waves.

Time S Arrows And Quantum Measurement

Autore: Lawrence S. Schulman
Editore: Cambridge University Press
ISBN: 9780521567756
Grandezza: 37,69 MB
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Vista: 3707
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An introduction to the arrow of time and a new, related, theory of quantum measurement.

A Quantum Measurement Approach To Tunnelling

Autore: D. K. Roy
Editore: World Scientific
ISBN: 9789810212230
Grandezza: 59,89 MB
Formato: PDF
Vista: 8335
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This book presents a new approach to analyze quantum mechanical tunnelling of particles across potential barriers. The conventional concepts of this phenomenon, which are based on a time-in-dependent or a time-dependent perturbation approach are inadequate in furnishing explanations to a number of effects, e.g. (i) the limit of resolution of a field emission macroscope (FEM), (ii) Esaki integral, representing the I-V characteristics of solid-state junctions, (iii) Josephson effect, (iv) tunnelling time, (v) tunnelling current density etc. The new analysis presented here not only provides adequate explanations to all the above mentioned effects but also furnishes an appropriate expression for the tunnelling current density which yields results closer to experimentally observed values.

Dark Matter In Cosmology Quantum Measurement Experimental Gravitation

Autore: R. Ansari
Editore: Atlantica Séguier Frontières
ISBN: 9782863322031
Grandezza: 11,68 MB
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Vista: 2419
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The Quantum Theory Of Measurement

Autore: Paul Busch
Editore: Springer Science & Business Media
ISBN: 3540372059
Grandezza: 13,56 MB
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Vista: 6410
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The amazing accuracy in verifying quantum effects experimentally has recently renewed interest in quantum mechanical measurement theory. In this book the authors give within the Hilbert space formulation of quantum mechanics a systematic exposition of the quantum theory of measurement. Their approach includes the concepts of unsharp objectification and of nonunitary transformations needed for a unifying description of various detailed investigations. The book addresses advanced students and researchers in physics and philosophy of science. In this second edition Chaps. II-IV have been substantially rewritten. In particular, an insolubility theorem for the objectification problem has been formulated in full generality, which includes unsharp object observables as well as unsharp pointers.

The Acquisition Of Information From Quantum Measurements

Autore: William Kent Wootters
Editore:
ISBN:
Grandezza: 14,22 MB
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Vista: 1586
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Quantum Chaos Quantum Measurement

Autore: P. Cvitanovic
Editore: Springer Science & Business Media
ISBN: 9401579792
Grandezza: 65,68 MB
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Vista: 7983
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This volume contains the proceedings of the NATO Advanced Research Workshop on `Quantum Chaos -- Theory and Experiment', held at the Niels Bohr Institute, University of Copenhagen, from 28 May to 1 June 1991. The work brings together leading quantum chaos theorists and experimentalists and greatly improves our understanding of the physics of quantum systems whose classical limit is chaotic. Quantum chaos is a subject of considerable current interest in a variety of fields, in particular nuclear physics, chemistry, statistical mechanics, atomic physics, condensed matter physics and nonlinear dynamics. The volume contains lectures about the currently most active fronts of quantum chaos, such as scars, semiclassical methods, quantum diffusion, random matrix spectra, quantum chaos in atomic and nuclear physics, and possible implications of quantum chaos for the problem of quantum measurement. Part of the book -- The Physics of Quantum Measurements -- is dedicated to the memory of John Bell.

Decoherence And Quantum Measurements

Autore: Mikio Namiki
Editore: World Scientific
ISBN: 9814497630
Grandezza: 72,95 MB
Formato: PDF
Vista: 9046
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The quantum measurement problem is one of the most fascinating and challenging topics in physics both theoretically and experimentally. It involves deep questions and the use of very sophisticated and elegant techniques. After analyzing the fundamental principles of quantum mechanics and of the Copenhagen interpretation, this book reviews the most important approaches to the measurement problem and rigorously reformulates the “collapse of the wave function” by measurement, as a dephasing process quantitatively characterized by an order parameter (called the decoherence parameter), according to the many-Hilbert-space approach to the problem. The book deals not only with the measurement processes (including imperfect measurements) but also with related interference and mesoscopic phenomena — by means of general arguments — of solvable models and of numerical simulations. The quantum Zeno effect and the issue of irreversibility are also discussed. Contents:General and Historical SurveyElements of Quantum MechanicsCritical Review of Measurement TheoriesThe Many-Hilbert-Space TheorySolvable Detector ModelsNeutron InterferometryNumerical Simulations of Measurement ProcessesQuantum Zeno EffectQuantum Dephasing by Chaos Readership: Physicists interested in the foundations of quantum theory. keywords:Decoherence;Irreversibility;Quantum Zeno Effect;Quantum Measurements;Environment;Classical Properties;Mesoscopic Systems;Time Evolutions;Projection Postulate;Collapse of the Wave Function “… considerable background material is given, allowing the volume to serve general educational and reference purposes as well. I can recommend it to anyone wanting an orientation to quantum measurement theory and, in particular, wanting to focus on the Many Hilbert Space Theory.” Foundations of Physics “The book may be useful both for students and experts.” Zentralblatt MATH

Quantum Measurement And Chaos

Autore: E. Pike
Editore: Springer
ISBN: 9781489953841
Grandezza: 80,27 MB
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Vista: 5899
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Continuous Quantum Measurements And Path Integrals

Autore: M.B Mensky
Editore: Routledge
ISBN: 1351458027
Grandezza: 16,65 MB
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Vista: 8372
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Advances in technology are taking the accuracy of macroscopic as well as microscopic measurements close to the quantum limit, for example, in the attempts to detect gravitational waves. Interest in continuous quantum measurements has therefore grown considerably in recent years. Continuous Quantum Measurements and Path Integrals examines these measurements using Feynman path integrals. The path integral theory is developed to provide formulae for concrete physical effects. The main conclusion drawn from the theory is that an uncertainty principle exists for processes, in addition to the familiar one for states. This implies that a continuous measurement has an optimal accuracy-a balance between inefficient error and large quantum fluctuations (quantum noise). A well-known expert in the field, the author concentrates on the physical and conceptual side of the subject rather than the mathematical.

A Quantum Measurement Approach To Tunnelling

Autore: Dilip K Roy
Editore: World Scientific
ISBN: 9814505056
Grandezza: 22,10 MB
Formato: PDF, Mobi
Vista: 395
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This book presents a new approach to analyze quantum mechanical tunnelling of particles across potential barriers. The conventional concepts of this phenomenon, which are based on a time-in-dependent or a time-dependent perturbation approach are inadequate in furnishing explanations to a number of effects, e.g. (i) the limit of resolution of a field emission macroscope (FEM), (ii) Esaki integral, representing the I-V characteristics of solid-state junctions, (iii) Josephson effect, (iv) tunnelling time, (v) tunnelling current density etc. The new analysis presented here not only provides adequate explanations to all the above mentioned effects but also furnishes an appropriate expression for the tunnelling current density which yields results closer to experimentally observed values. Contents:IntroductionConventional Analysis of the Tunnel EffectTheory of Quantum Measurement and ObservationsTunnelling from the Viewpoint of Quantum Measurement Readership: Condensed matter physicists, researchers in semiconductors and physicists in general. keywords:Tunnelling (Tunneling);Quantum Measurement;Quantum Scattering;Barrier Penetration;Tunnelling Time;WKB Approx.to Tunnelling;Barrier Wavefunction;Tunnelling Current Density;Time-dependent Potential Energy;Kinetic Energy during Tunnelling

Electromagnetic And Quantum Measurements

Autore: Tore Wessel-Berg
Editore: Springer Science & Business Media
ISBN: 9780792372578
Grandezza: 58,80 MB
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Vista: 9025
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This book presents a generalization of electromagnetism into the bitemporal microcosm, where by hypothesis regular causal relationships do not apply, and time is allowed to flow in both directions. Labeled the Neo-classical Electromagnetic Theory, the proposition is put on a sound formal footing by noting that Maxwell's field equations are valid for positive as well as negative time. The book explores the ramifications of the extra degree of freedom arising from incorporation of negative time elements, which introduce additional boundary conditions modifying orthodox quantum interpretations in a nontrivial way. The theory provides a merger of electromagnetism and quantum theory of photons, applicable to macroscopic as well as microscopic phenomena. Avoiding the hand-waving arguments so often encountered in quantum texts, the book presents detailed analyses of a number of well-known and famous quantum experiments riddled with interpretational dilemmas, such as the double-slit experiments for photons and electrons, the Einstein-Podolsky-Rosen (EPR) paradox, and many more. The investigations turned out to be a fascinating journey into largely unexplored territory, with rewards in the way of resolutions of bizarre puzzles and paradoxes in the quantum family, together with consistent agreements with existing experimental facts. In examples from the macroscopic domain, the book proposes a photonic origin of the enigmatic 1/f noise occurring in all active electronic components and devices, a proposition supported by detailed analysis consistent with existing empirical data. Incorporation of negative time elements into the field equations gives rise to the concept of photon doublets, a composite entity consisting of a bitemporal photon pair of zero net energy, which in the neo-classical theory fills all vacuum space. In this theory the doublet entities replace the so-called Zero Point Fluctuations of conventional quantum theory, which predicts infinite energy density of the vacuum state, an embarrassing concept remaining a puzzle to contemporary physicists, as well as to cosmologists. From its electromagnetic platform the Neo-classical Theory takes the consistent view that quantum phenomena are objective entities, describing these in an overall theoretical framework that can be characterized as an observer-independent quantum theory. From this viewpoint alone the book is an important contribution to the ongoing debate of the true interpretation of the quantum world.