Quantum Uncertainties

Quantum Uncertainties


Quantum Uncertainties

Quantum Uncertainties Edited by William M. Honig David W. Kraft and Emilio Panarella NATO AS Series Series B: Physics Vol. 162 Quantum Uncertainties Recent and Future Experiments and Interpretations NATO ASI.

Quantum Uncertainties


Quantum Uncertainties

Quantum Uncertainties


Surfing the Quantum World

It depends instead on what the two observables are. If the corresponding quantum operators commute, then quantum theory places no limits on the uncertainties: they can be made as small as the equipment will allow.

Surfing the Quantum World

The ideas and phenomena of the quantum world are strikingly unlike those encountered in our visual world. Surfing the Quantum World shows why and how this is so. It does this via a historical review and a gentle introduction to the fundamental principles of quantum theory, whose core concepts and symbolic representations are used to explain not only "ordinary" microscopic phenomena like the properties of the hydrogen atom and the structure of the Periodic Table of the Elements, but also a variety of mind-bending phenomena. Readers will learn that particles such as electrons and photons can behave like waves, allowing them to be in two places simultaneously, why white dwarf and neutron stars are gigantic quantum objects, how the maximum height of mountains has a quantum basis, and why quantum objects can tunnel through seemingly impenetrable barriers. Included among the various interpretational issues addressed is whether Schrödinger's cat is ever both dead and alive.

Probing the Structure of Quantum Mechanics

QUANTUM CRYPTOGRAPHY WITHOUT QUANTUM UNCERTAINTIES THOMAS DURT Foundations of the Exact Sciences ( FUND ) and Applied Physics and Photonics ( TONA ) , Brussels Free University , Pleinlaan 2 , 1050 Brussels , Belgium E - mail ...

Probing the Structure of Quantum Mechanics

During the last decade, scientists working in quantum theory have been engaging in promising new fields such as quantum computation and quantum information processing, and have also been reflecting on the possibilities of nonlinear behavior on the quantum level. These are challenging undertakings because (1) they will result in new solutions to important technical and practical problems that were unsolvable by the classical approaches (for example, quantum computers can calculate problems that are intractable if one uses classical computers); and (2) they open up new 'hard' problems of a fundamental nature that touch the foundation of quantum theory itself (for example, the contradiction between locality and nonlinearity and the interpretation of quantum computing as a universal process).In this book, one can distinguish two main streams of research to approach the just-mentioned problem field: (1) a theoretical structural part, which concentrates on the elaboration of a nonlinear quantum mechanics and the fundamentals of quantum computation; and (2) a theoretical experimental part, which focuses on the theoretical aspects of applications that arise from new technology and novel research perspectives such as quantum optics and quantum cryptography. Particular attention is also paid to the measurement problem, the classical limit and alternative interpretations (such as the hidden measurement approach).

Quantum Optics

Finally, we introduce the quantum uncertainty of the harmonic oscillator given in eqn 7.32 to obtain: ∆X1∆X 2 ≥ 1 4. (7.35) We therefore conclude that the field quadratures are subject to quantum uncertainty in exact analogy to the ...

Quantum Optics

Written primarily for advanced undergraduate and masters level students in physics, this text includes a broad range of topics in applied quantum optics such as laser cooling, Bose-Einstein condensation and quantum information processing.

Quantum Processes Systems and Information

Strictly speaking, Eq. 5.29 holds only if the uncertainty C is sufficiently small, but that will be good enough for our purposes. Now consider the quantum mechanics of the situation. The clock is a quantum system whose evolution is ...

Quantum Processes Systems  and Information

A new and exciting approach to the basics of quantum theory, this undergraduate textbook contains extensive discussions of conceptual puzzles and over 800 exercises and problems. Beginning with three elementary 'qubit' systems, the book develops the formalism of quantum theory, addresses questions of measurement and distinguishability, and explores the dynamics of quantum systems. In addition to the standard topics covered in other textbooks, it also covers communication and measurement, quantum entanglement, entropy and thermodynamics, and quantum information processing. This textbook gives a broad view of quantum theory by emphasizing dynamical evolution, and exploring conceptual and foundational issues. It focuses on contemporary topics, including measurement, time evolution, open systems, quantum entanglement, and the role of information.

Quantum Mechanics

velocity uncertainty is inversely proportional to the mass, for fixed ∆k, which explains the slower spread of ... There is one point that one always has to keep in mind when thinking about quantum uncertainties for macroscopic objects.

Quantum Mechanics

This authoritative, advanced introduction provides a complete, modern perspective on quantum mechanics. It clarifies many common misconceptions regarding wave/particle duality and the correct interpretation of measurements. The author develops the text from the ground up, starting from the fundamentals and presenting information at an elementary level, avoiding unnecessarily detailed and complex derivations in favor of simple, clear explanations. He begins in the simplest context of a two-state system and shows why quantum mechanics is inevitable, and what its relationship is to classical mechanics. He also outlines the decoherence approach to interpreting quantum mechanics. Distinguishing features: Provides a thorough grounding in the principles and practice of quantum mechanics, including a core understanding of the behavior of atoms, molecules, solids, and light. Utilizes easy-to-follow examples and analogies to illustrate important concepts. Helps develop an intuitive sense for the field, by guiding the reader to understand how the correct formulas reduce to the non-relativistic ones. Includes numerous worked examples and problems for each chapter.

Quantum Optics

Abstract Current attempts to detect gravitational radiation have to take into account the quantum uncertainties in the measurement process. Considering that the detectors are macroscopic objects in some cases as large as a 10-ton bar, ...

Quantum Optics

The formalism of quantum optics is elucidated in the early chapters and the main techniques are introduced. These are applied in the later chapters to problems such as squeezed states of light, resonance fluorescence, laser theory, quantum theory of four-wave mixing, quantum non-demolition measurements, Bell's inequalities, and atom optics. Experimental results are used to illustrate the theory throughout. This yields the most comprehensive and up-to-date coverage of experiment and theory in quantum optics in any textbook.

Microphysical Reality and Quantum Formalism

In his Chicago lectures of 1929 , Eign Heisenberg regarded this inequality as the precise mathematical expression of the uncertainty principle within the formalism of quantum mechanics . The next important step was taken in 1929 ...

Microphysical Reality and Quantum Formalism

"Proceedings of the conference 'Microphysical reality and quantum formalism', Urbino, Italy, September 25th-October 3rd, 1985."

Quantum Information with Continuous Variables

The ellipses and circles depict the quantum uncertainties of the optical fields (i. e. the half-height contours of Wigner functions) and the sticks relate to the strong classical amplitudes. The uncertainty areas of the input fields are ...

Quantum Information with Continuous Variables

Quantum information may sound like science fiction but is, in fact, an active and extremely promising area of research, with a big dream: to build a quantum computer capable of solving problems that a classical computer could not even begin to handle. Research in quantum information science is now at an advanced enough stage for this dream to be credible and well-worth pursuing. It is, at the same time, too early to predict how quantum computers will be built, and what potential technologies will eventually strike gold in their ability to manipulate and process quantum information. One direction that has reaped many successes in quantum information processing relies on continuous variables. This area is bustling with theoretical and experimental achievements, from continuous-variable teleportation, to in-principle demonstrations of universal computation and efficient error correction. Now the time has come to compile some of the major results into one volume. In this book the leading researchers of the field present up-to-date developments of continuous-variable quantum information. This book is organized to suit many reader levels with introductions to every topic and in-depth discussions of theoretical and experimental results.

Quantum Mechanics for Pedestrians 1 Fundamentals

In fact, the experimental errors of measuring instruments in real experiments are usually much larger than the quantum uncertainties. Accordingly, the uncertainty relation is not a statement about the accuracy of measuring instruments, ...

Quantum Mechanics for Pedestrians 1  Fundamentals

This book provides an introduction into the fundamentals of non-relativistic quantum mechanics. In Part 1, the essential principles are developed. Applications and extensions of the formalism can be found in Part 2. The book includes not only material that is presented in traditional textbooks on quantum mechanics, but also discusses in detail current issues such as interaction-free quantum measurements, neutrino oscillations, various topics in the field of quantum information as well as fundamental problems and epistemological questions, such as the measurement problem, entanglement, Bell's inequality, decoherence, and the realism debate. A chapter on current interpretations of quantum mechanics concludes the book. To develop quickly and clearly the main principles of quantum mechanics and its mathematical formulation, there is a systematic change between wave mechanics and algebraic representation in the first chapters. The required mathematical tools are introduced step by step. Moreover, the appendix collects compactly the most important mathematical tools that supplementary literature can be largely dispensed. In addition, the appendix contains advanced topics, such as Quantum- Zeno effect, time-delay experiments, Lenz vector and the Shor algorithm. About 250 exercises, most of them with solutions, help to deepen the understanding of the topics.

Exploring Quantum Foundations with Single Photons

6.1 The three faces of Heisenberg's uncertainty principle. a Preparation Uncertainty. A quantum system cannot be prepared in a state ρ, such that two incompatible observables A and B are arbitrarily well defined on ρ. b ...

Exploring Quantum Foundations with Single Photons

This thesis uses high-precision single-photon experiments to shed new light on the role of reality, causality, and uncertainty in quantum mechanics. It provides a comprehensive introduction to the current understanding of quantum foundations and details three influential experiments that significantly advance our understanding of three core aspects of this problem. The first experiment demonstrates that the quantum wavefunction is part of objective reality, if there is any such reality in our world. The second experiment shows that quantum correlations cannot be explained in terms of cause and effect, even when considering superluminal influences between measurement outcomes. The final experiment in this thesis demonstrates a novel uncertainty relation for joint quantum measurements, where the textbook relation does not apply.

Fundamental Problems in Quantum Physics

He has shown that the quantum mechanical uncertainties in the positions and momenta of material bodies induce a minimal unavoidable uncertainty in the length of time intervals (see Eq.(1) below), and he has proposed to loosen the ...

Fundamental Problems in Quantum Physics

For many physicists quantum theory contains strong conceptual difficulties, while for others the apparent conclusions about the reality of our physical world and the ways in which we discover that reality remain philosophically unacceptable. This book focuses on recent theoretical and experimental developments in the foundations of quantum physics, including topics such as the puzzles and paradoxes which appear when general relativity and quantum mechanics are combined; the emergence of classical properties from quantum mechanics; stochastic electrodynamics; EPR experiments and Bell's Theorem; the consistent histories approach and the problem of datum uniqueness in quantum mechanics; non-local measurements and teleportation of quantum states; quantum non-demolition measurements in optics and matter wave properties observed by neutron, electron and atomic interferometry. Audience: This volume is intended for graduate students of physics and those interested in the foundations of quantum theory.

Quantum Information with Continuous Variables of Atoms and Light

an ensemble of identically prepared atomic systems and this measurement uncertainty is generally termed spin projection noise.11 It can be extremely convenient to visualize the spin-polarized quantum system as though it were a classical ...

Quantum Information with Continuous Variables of Atoms and Light

Quantum information describes the new field which bridges quantum physics and information science. The quantum world allows for completely new architectures and protocols. While originally formulated in continuous quantum variables, the field worked almost exclusively with discrete variables, such as single photons and photon pairs. The renaissance of continuous variables came with European research consortia such as ACQUIRE (Advanced Coherent Quantum Information Research) in the late 1990s, and QUICOV (Quantum Information with Continuous Variables) from 2000OCo2003. The encouraging research results of QUICOV and the new conference series CVQIP (Continuous Variable Quantum Information Processing) triggered the idea for this book. This book presents the state of the art of quantum information with continuous quantum variables. The individual chapters discuss results achieved in QUICOV and presented at the first five CVQIP conferences from 2002OCo2006. Many world-leading scientists working on continuous variables outside Europe also contribute to the book.

Quantum Theory Concepts and Methods

Both operators are self-adjoint if the inner product of two vectors is We then obtain the standard uncertainty relation (4.53) (4.54) Now, since both x and p are unbounded operators, there are functions lying outside their domains of ...

Quantum Theory  Concepts and Methods

There are many excellent books on quantum theory from which one can learn to compute energy levels, transition rates, cross sections, etc. The theoretical rules given in these books are routinely used by physicists to compute observable quantities. Their predictions can then be compared with experimental data. There is no fundamental disagreement among physicists on how to use the theory for these practical purposes. However, there are profound differences in their opinions on the ontological meaning of quantum theory. The purpose of this book is to clarify the conceptual meaning of quantum theory, and to explain some of the mathematical methods which it utilizes. This text is not concerned with specialized topics such as atomic structure, or strong or weak interactions, but with the very foundations of the theory. This is not, however, a book on the philosophy of science. The approach is pragmatic and strictly instrumentalist. This attitude will undoubtedly antagonize some readers, but it has its own logic: quantum phenomena do not occur in a Hilbert space, they occur in a laboratory.

Quantum Art Uncertainty

At the core of both art and science we find the twin forces of probability and uncertainty.

Quantum Art   Uncertainty

All we know for certain is that both art and science have probability and uncertainty at their core. However, these two worlds have been tenuously entangled for decades. On the one hand, artists continue to ask complex questions that align with a scientific fascination of new discoveries, and on the other hand, the appreciation that creativity and subjectivity inform science’s objective processes and knowledge systems is ever increasing. In order to draw parallels between art, science and culture, the way that selected art works have contributed to a form of cultural pedagogy will be explored in this publication. It follows the integration of the artists’ expression, linked with culture and science, to create meaningful experiences that expose the probabilities and uncertainties reinforced by the world of science.

Knowledge Potential Measurement and Uncertainty

Honig, W., Kraft, D., Panarella, E.: Quantum Uncertainties. Recent and Future Experiments and Interpretations. NATO ASI Series. Plenum Press, New York/London 1987. Holden, N.: Cross-Cultural Management. A Knowledge Perspective.

Knowledge Potential Measurement and Uncertainty

Kerstin Fink discusses the two mainstream measurement fields: the cognitive science approach and the management approach. She develops the knowledge potential view which is determined by nine key measurement variables, i.e. content, culture, networking, organizational knowledge, learning and training, customer and competitor knowledge, and knowledge management systems.

Quantum Gravity

This chain of arguments leaves the linear structure of quantum theory untouched, which corresponds to an Everett ... It cannot be concluded from this analysis alone that the validity of quantum uncertainty relations in one system ...

Quantum Gravity

The search for a quantum theory of the gravitational field is one of the great open problems in theoretical physics. This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory. The two main approaches to its construction — the direct quantisation of Einstein's general theory of relativity and string theory — are covered. Whereas the first attempts to construct a viable theory for the gravitational field alone, string theory assumes that a quantum theory of gravity will be achieved only through a unification of all the interactions. However, both employ the general method of quantization of constrained systems, which is described together with illustrative examples relevant for quantum gravity. There is a detailed presentation of the main approaches employed in quantum general relativity: path-integral quantization, the background-field method and canonical quantum gravity in the metric, connection and loop formulations. The discussion of string theory centres around its quantum-gravitational aspects and the comparison with quantum general relativity. Physical applications discussed at length include the quantization of black holes, quantum cosmology, the indications of a discrete structure of spacetime, and the origin of irreversibility. This third edition contains new chapters or sections on quantum gravity phenomenology, Horava-Lifshitz quantum gravity, analogue gravity, the holographic principle, and affine quantum gravity. It will present updates on loop quantum cosmology, the LTB model, asymptotic safety, and various discrete approaches. The third edition also contains pedagogical extensions throughout the text. This book will be of interest to researchers and students working in relativity and gravitation, cosmology, quantum field theory and related topics. It will also be of interest to mathematicians and philosophers of science.

Schr dinger s Killer App

Race to Build the World's First Quantum Computer Jonathan P. Dowling. (just like the photoelectric effect with ... These quantum uncertainties are inversely proportional to the mass of the object. My car, because it is much heavier than ...

Schr  dinger s Killer App

The race is on to construct the first quantum code breaker, as the winner will hold the key to the entire Internet. From international, multibillion-dollar financial transactions to top-secret government communications, all would be vulnerable to the secret-code-breaking ability of the quantum computer. Written by a renowned quantum physicist closely involved in the U.S. government’s development of quantum information science, Schrödinger’s Killer App: Race to Build the World’s First Quantum Computer presents an inside look at the government’s quest to build a quantum computer capable of solving complex mathematical problems and hacking the public-key encryption codes used to secure the Internet. The "killer application" refers to Shor’s quantum factoring algorithm, which would unveil the encrypted communications of the entire Internet if a quantum computer could be built to run the algorithm. Schrödinger’s notion of quantum entanglement—and his infamous cat—is at the heart of it all. The book develops the concept of entanglement in the historical context of Einstein’s 30-year battle with the physics community over the true meaning of quantum theory. It discusses the remedy to the threat posed by the quantum code breaker: quantum cryptography, which is unbreakable even by the quantum computer. The author also covers applications to other important areas, such as quantum physics simulators, synchronized clocks, quantum search engines, quantum sensors, and imaging devices. In addition, he takes readers on a philosophical journey that considers the future ramifications of quantum technologies. Interspersed with amusing and personal anecdotes, this book presents quantum computing and the closely connected foundations of quantum mechanics in an engaging manner accessible to non-specialists. Requiring no formal training in physics or advanced mathematics, it explains difficult topics, including quantum entanglement, Schrödinger’s cat, Bell’s inequality, and quantum computational complexity, using simple analogies.