Kvantefysik (kvantemekanik og kvantefeltteori)

This volume celebrates the 100th birthday of Professor Chen-Ning Frank Yang (Nobel 1957), one of the giants of modern science and a living legend. Starting with reminiscences of Yang's time at the research centre for theoretical physics at Stonybrook (now named C. N. Yang Institute) by his successor Peter van Nieuwenhuizen, the book is a collection of articles by world-renowned mathematicians and theoretical physicists. This emphasizes the Dialogue Between Physics and Mathematics that has been a central theme of Professor Yang's contributions to contemporary science. Fittingly, the contributions to this volume range from experimental physics to pure mathematics, via mathematical physics. On the physics side, the contributions are from Sir Anthony Leggett (Nobel 2003), Jian-Wei Pan (Willis E. Lamb Award 2018), Alexander Polyakov (Breakthrough Prize 2013), Gerard 't Hooft (Nobel 1999), Frank Wilczek (Nobel 2004), Qikun Xue (Fritz London Prize 2020), and Zhongxian Zhao (Bernd T. Matthias Prize 2015), covering an array of topics from superconductivity to the foundations of quantum mechanics. In mathematical physics there are contributions by Sir Roger Penrose (Nobel 2022) and Edward Witten (Fields Medal 1990) on quantum twistors and quantum field theory, respectively. On the mathematics side, the contributions by Vladimir Drinfeld (Fields Medal 1990), Louis Kauffman (Wiener Gold Medal 2014), and Yuri Manin (Cantor Medal 2002) offer novel ideas from knot theory to arithmetic geometry.Inspired by the original ideas of C. N. Yang, this unique collection of papers b masters of physics and mathematics provides, at the highest level, contemporary research directions for graduate students and experts alike.

This book provides a comprehensive introduction to photoelectron angular distributions and their use in the laboratory to study light-matter interactions. Photoelectron angular distribution measurements are useful because they can shed light on atomic and molecular electronic configurations and system dynamics, as well as provide information about quantum transition amplitudes and relative phases that are not obtainable from other types of measurements. For example, recent measurements of molecular-frame photoelectron angular distributions have been used to extract photoelectron emission delays in the attosecond range which can provide ultra-sensitive maps of molecular potentials. Additionally, photoelectron angular distribution measurements are an essential tool for studying negative ions.Here, the author presents a detailed, yet easily accessible, theoretical background necessary for experimentalists performing photoelectron angular distribution measurements to better understand their results. The various physical influences on photoelectron angular distributions are revealed through analytical models with the use of angular momentum coupling algebra and spherical tensor operators. The classical and quantum treatments of photoelectron angular distributions are covered clearly and systematically, and the book includes, as well, a chapter on relativistic interactions. Furthermore, the primary methods used to measure photoelectron angular distributions in the laboratory, such as photodetachment electron spectroscopy, velocity-map imaging, and cold target recoil ion momentum spectroscopy, are described. This book features introductory material as well as new insights on the topic, such as the use of angular momentum transfer theory to understand the process of photoelectron detachment in atoms and molecules. Including key derivations, worked examples, and additional exercises for readers to try on their own, this book serves as both a critical guide for young researchers entering the field and as a useful reference for experienced practitioners.

This book highlights quantum optics technologies that can revolutionize the way we encode, store, transmit, and handle information. These technologies can help us overcome bottlenecks in classical physics-based information technology in information transmission capacity, computing speed, and information security. The book provides readers with new perspectives on potential applications of the quantum theory. Besides, the book summaries the research advances in quantum optics and atom optics, including manipulation and construction of the quantum states of photons and even atoms, molecules, and matter at the quantum level, and new phenomena and technologies brought about by the interactions between photons and the quantum states of matter. The book provides extensive and thoroughly exhaustive coverage of quantum optics. It is suitable for researchers and graduate students of optical physics and quantum optics.

This book offers a brief but effective introduction to quantum machine learning (QML). QML is not merely a translation of classical machine learning techniques into the language of quantum computing, but rather a new approach to data representation and processing. Accordingly, the content is not divided into a "classical part" that describes standard machine learning schemes and a "quantum part" that addresses their quantum counterparts. Instead, to immerse the reader in the quantum realm from the outset, the book starts from fundamental notions of quantum mechanics and quantum computing. Avoiding unnecessary details, it presents the concepts and mathematical tools that are essential for the required quantum formalism. In turn, it reviews those quantum algorithms most relevant to machine learning. Later chapters highlight the latest advances in this field and discuss the most promising directions for future research.To gain the most from this book, a basic grasp of statistics and linear algebra is sufficient; no previous experience with quantum computing or machine learning is needed. The book is aimed at researchers and students with no background in quantum physics and is also suitable for physicists looking to enter the field of QML.

This book provides readers with the current state-of-the-art research and technology on quantum computing. The authors provide design paradigms of quantum computing. Topics covered include multi-programming mechanisms on near-term quantum computing, Lagrange interpolation approach for the general parameter-shift rule, architecture-aware decomposition of quantum circuits, software for massively parallel quantum computing, machine learning in quantum annealing processors, quantum annealing for real-world machine learning applications, queuing theory models for (Fault-Tolerant) quantum circuits, machine learning for quantum circuit reliability assessment, and side-channel leakage in Suzuki stack circuits.

This wide-ranging book introduces information as a key concept not only in physics, from quantum mechanics to thermodynamics, but also in the neighboring sciences and in the humanities. The central part analyzes dynamical processes as manifestations of information flows between microscopic and macroscopic scales and between systems and their environment. Quantum mechanics is interpreted as a reconstruction of mechanics based on fundamental limitations of information processing on the smallest scales. These become particularly manifest in quantum chaos and in quantum computing. Covering subjects such as causality, prediction, undecidability, chaos, and quantum randomness, the book also provides an information-theoretical view of predictability. More than 180 illustrations visualize the concepts and arguments. The book takes inspiration from the author's graduate-level topical lecture but is also well suited for undergraduate studies and is a valuable resource for researchers and professionals.

Dynamic Environments Testing, Volume 7: Proceedings of the 41st IMAC, A Conference and Exposition on Structural Dynamics, 2023, the seventh volume of ten from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects Dynamic Environments Testing including papers on:Vibration Testing Shock TestingMulti-Axis Shaker Testing Test Fixture Design Dynamic Environment Definition Specifications for Acceptance Testing

In einer umfassenden Darstellung entwickeln und vertiefen die vier Bände dieses Lehrbuchs das Gebäude der nichtrelativistischen Quantenmechanik, weshalb sie auch bestens als Nachschlagewerk geeignet sind.Der vierte Band beginnt mit einem ausführlichen Kapitel zur nichtrelativistischen Quantenelektrodynamik (QED), traditionell als "Quantentheorie der Strahlung" bezeichnet, und leitet dann über in die relativistische Quantentheorie. Eine sorgfältige Behandlung der Möglichkeiten und Grenzen einer relativistischen Quantenmechanik sowie eine gründliche Untersuchung von Symmetrien in der relativistischen Quantentheorie schließen das Lehrbuch ab.Besonderheiten:Auch komplizierte Zusammenhänge werden illustrativ und klar erklärt. Zahlreiche mathematische Einschübe erläutern allgemeine mathematische Zusammenhänge. Besondere Highlights des Buches sind eine ausführliche Diskussionder Lamb-Verschiebung und des Casimir-Effekts, einschließlich der in diesem Zusammenhang offenbar werdenden Problematik der Renormierung, sowie die Analyse der Einteilchen-Interpretation in der relativistischen Quantenmechanik und die Betrachtung von Gruppenkontraktionen im Übergang von relativistischen zu nichtrelativistischen Symmetriegruppen und ihrer Darstellungen.Inhalt1. Quantisierung des elektromagnetischen Feldes - 2. Relativistische Quantenmechanik - 3. Symmetrien in der Quantenmechanik IIZielgruppe:Das Buch richtet sich sowohl an Bachelor- als auch an Masterstudierende sowie ihre Lehrenden. Aufgrund seines mehrbändigen Charakters, der breiten Themenvielfalt und Bezügen zu wissenschaftlichen Originalarbeiten allerdings ein Muss für jedes Bücherregal einer in der Physik tätigen Person.Vorkenntnisse:Vorausgesetzt werden Kenntnisse der Theoretischen Mechanik, der Elektrodynamik und der Speziellen Relativitätstheorie, sowie der Analysis, der linearen Algebra und der Funktionentheorie.

A new interpretation of quantum physics:For 100 years, most physicists have believed that it is no longer possible to understand the true constitution of nature. This is due to the unresolved wave-particle paradox, the apparent contradiction between wholeness and divisibility - that subtle smile of Nature that seemed so confusing that theoretical physics threw in the towel in despair as early as 1927. This was a direct consequence of the Copenhagen Interpretation, in which Niels Bohr had postulated an insurmountable barrier of cognition (at least for physicists).In reality, however, the underlying experiments are of a poignant simplicity that even laymen can understand: They reveal holistic division and branching processes of matter and light. This fact refutes the atomic hypothesis, the hypothesis of indivisibility, on which our current world view is based. This is precisely the fundamental natural philosophical problem of physics: although the experiment clearly proves that the 2400-year-old Greek idea of the existence of atoms - i.e. indivisible particles - cannot apply to nature and reality, we have not yet been able to understand the 'actual punchline of this joke' (Einstein): The key point is simply that physics, like biology, proves the existence of holistic division processes, which requires a revolution of physics.Volume 1 introduces the quantum puzzle and identifies the four cognitive problems of quantum physics. They are obviously caused by assumptions that are considered proven, but must nevertheless be false. So we embark on a detective search for clues in the history of ideas in 19th century physics. The investigation reveals, among other things, that the indivisibility hypothesis already failed experimentally justified in the founding days of chemistry, which led Avogadro to the hypothesis of divisible 'atoms', called integral molecules. If we now interpret this divisibility as molecular cell division, the atom concept becomes obsolete.

In recent years, nanoelectronics has become very interdisciplinary requiring students to master aspects of physics, electrical engineering, chemistry etc. The 2nd edition of this textbook is a comprehensive overview of nanoelectronics covering the necessary quantum mechanical and solid-state physics foundation, an overview of semiconductor fabrication as well as a brief introduction into device simulation using the non-equilibrium Greens function formalism. Equipped with this, the work discusses nanoscale field-effect transistors and alternative device concepts such as Schottky-barrier MOSFETs as well as steep slope transistors based on different materials. In addition, cryogenic operation of MOSFETs for the realization of, e.g., classical control electronics of semiconducting spin qubits is studied. The work contains a number of tasks, examples and exercises with step-by-step video solutions as well as tutorial videos that deepen the understanding of the material. With additional access to simulation tools that allow students to do computational experiments, the emphasis is on thorough explanation of the material enabling students to carry out their own research.

This textbook provides ample opportunities for practice and real experimental demonstrations. Conceptual understanding and mastering key techniques are enhanced by rigorous derivations, numerous worked examples, more than 300 exercises, about 150 problems and 16 computer codes. The preface summarizes all of the key concepts and formulas, along with a detailed schedule for teaching. The first three chapters introduce the quantum idea, wave-particle duality, operators and measurement. The Noether theorem is invoked to introduce the Schrödinger equation, followed by applications to infinite and finite quantum wells, quantum tunneling, harmonic oscillators, Heisenberg equation of motion, uncertainty principle, blackbody radiation and photoelectric effect. Chapters 4 and 5 are on angular momentum, the hydrogen atom and time-independent approximate methods. Chapters 6 and 7 are on spin and time-dependent perturbation theory. Chapters 8, 9 and 10 are on molecular orbitals, energy bands, quantum transport, scanning tunneling microscopy, lattice vibrations, Berry phase and quantum computing. The book is intended for a one-semester or one-year course and is also appropriate for researchers in related fields.

This book presents a collection of articles reporting the current challenges in solid and fracture mechanics. The book is devoted to the 90th birthday of academician Nikita F. Morozov-a well-known specialist in the field of solid and fracture mechanics.

This open access book gives a systematic introduction into the spectral theory of differential operators on metric graphs. Main focus is on the fundamental relations between the spectrum and the geometry of the underlying graph.The book has two central themes: the trace formula and inverse problems.The trace formula is relating the spectrum to the set of periodic orbits and is comparable to the celebrated Selberg and Chazarain-Duistermaat-Guillemin-Melrose trace formulas. Unexpectedly this formula allows one to construct non-trivial crystalline measures and Fourier quasicrystals solving one of the long-standing problems in Fourier analysis. The remarkable story of this mathematical odyssey is presented in the first part of the book.To solve the inverse problem for Schrödinger operators on metric graphs the magnetic boundary control method is introduced. Spectral data depending on the magnetic flux allow one to solve the inverse problem in full generality, this means to reconstruct not only the potential on a given graph, but also the underlying graph itself and the vertex conditions.The book provides an excellent example of recent studies where the interplay between different fields like operator theory, algebraic geometry and number theory, leads to unexpected and sound mathematical results. The book is thought as a graduate course book where every chapter is suitable for a separate lecture and includes problems for home studies. Numerous illuminating examples make it easier to understand new concepts and develop the necessary intuition for further studies.

This book explores music with respect to quantum computing, a nascent technology that is advancing rapidly. There is a long history of research into using computers for music since the 1950s.Nowadays, computers are essential for the music economy. Therefore, it is very likely that quantum computers will impact the music industry in the time to come.  Consequently, a new area of research and development is emerging: Quantum Computer Music.This unprecedented book presents the new field of Quantum Computer Music. It introduces the fundamentals of quantum computing for musicians and the latest developments by pioneering practitioners.

The Standard Model of elementary particle physics was tentatively outlined in the early 1970s. The concepts of quarks, leptons, neutrinos, gauge symmetries, chiral interactions, Higgs boson, strong force, weak force, and electromagnetism were all put together to form a unifying theory of elementary particles. Furthermore, the model was developed within the context of relativistic quantum field theory, making it compatible with all of the laws of Einstein's Special Relativity. The successes of the Standard Model over the years have been tremendous and enduring, leading up to the recent discovery and continuing study of the Higgs boson.      This book is a comprehensive and technical introduction to Standard Model physics. Martin and Wells provide readers who have no prior knowledge of quantum field theory or particle physics a firm foundation into the fundamentals of both. The emphasis is on obtaining practical knowledge of how to calculate cross-sections and decay rates. There is no better way to understand the necessary abstract knowledge and solidify its meaning than to learn how to apply it to the computation of observables that can be measured in a laboratory.Beginning graduate students, both experimental and theoretical, and advanced undergraduate students interested in particle physics, will find this to be an ideal one-semester textbook to begin their technical learning of elementary particle physics.

Based on Jost function theory this book presents an approach useful for different types of quantum mechanical problems. These include the description of scattering, bound, and resonant states, in a unified way. The reader finds here all that is known about Jost functions as well as what is needed to fill the gap between the pure mathematical theory and numerical calculations. Some of the topics covered are: quantum resonances, Regge poles, multichannel scattering, Coulomb interaction, Riemann surfaces, multichannel analog of the effective range theory, one- and two-dimensional problems, many-body problems within the hyperspherical approach, just to mention few of them. These topics are relevant in the fields of quantum few-body theory, nuclear reactions, atomic collisions, and low-dimensional semiconductor nanostructures. In light of this, the book is meant for students, who study quantum mechanics, scattering theory, or nuclear reactions at the advanced level as well as for post-graduate students and researchers in the fields of nuclear and atomic physics. Many of the arguments that are traditional for textbooks on quantum mechanics and scattering theory, are covered here in a different way, using the Jost functions. This gives the reader a new insight into the subject, revealing new features of various mathematical objects and quantum phenomena.

This book provides the rigorous mathematical foundations of Quantum Physics, from the operational meaning of the measuring process to the most recent theories for the quantum scale of space-time geometry. Topics like relativistic invariance, quantum systems with finite and infinitely many degrees of freedom, second quantisation, scattering theory, are all presented through the formalism of Operator Algebras for a precise mathematical justification.The book is targeted to graduate students and researchers in the area of theoretical/mathematical physics who want to learn about the mathematical foundations of quantum physics, as well as the mathematics students and researchers in the area of operator algebras/functional analysis who want to dive into some of the applications of the theory to physics. 

This thesis presents the first realization of non-reciprocal energy transfer between two cantilevers by quantum vacuum fluctuations. According to quantum mechanics, vacuum is not empty but full of fluctuations due to zero-point energy. Such quantum vacuum fluctuations can lead to an attractive force between two neutral plates in vacuum ¿ the so-called Casimir effect ¿ which has attracted great attention as macroscopic evidence of quantum electromagnetic fluctuations, and can dominate the interaction between neutral surfaces at small separations. The first experimental demonstration of diode-like energy transport in vacuum reported in this thesis is a breakthrough in Casimir-based devices. It represents an efficient and robust way of regulating phonon transport along one preferable direction in vacuum. In addition, the three-body Casimir effects investigated in this thesis were used to realize a transistor-like three-terminal device with quantum vacuum fluctuations. These two breakthroughs pave the way for exploring and developing advanced Casimir-based devices with potential applications in quantum information science. This thesis also includes a study of the non-contact Casimir friction, which will enrich the understanding of quantum vacuum fluctuations.

This book presents a set of software engineering techniques and tools to improve the productivity and assure the quality in quantum software development. Through the collaboration of the software engineering community with the quantum computing community new architectural paradigms for quantum-enabled computing systems will be anticipated and developed.The book starts with a chapter that introduces the main concepts and general foundations related to quantum computing. This is followed by a number of chapters dealing with the quantum software engineering methods and techniques. Topics like the Talavera Manifesto for quantum software engineering, frameworks for hybrid systems, formal methods for quantum software engineering, quantum software modelling languages, and reengineering for quantum software are covered in this part. A second set of chapters then deals with quantum software environments and tools, detailing platforms like QuantumPath(R), Classiq as well as quantum software frameworks for deep learning. Overall, the book aims at academic researchers and practitioners involved in the creation of quantum information systems and software platforms. It is assumed that readers have a background in traditional software engineering and information systems.

This thesis explores the physics of non-equilibrium quantum dynamics in homogeneous two-dimensional (2D) quantum gases. Ultracold quantum gases driven out of equilibrium have been prominent platforms for studying quantum many-body physics. However, probing non-equilibrium dynamics in conventionally trapped, inhomogeneous atomic quantum gases has been a challenging task because coexisting mass transport and spreading of quantum correlations often complicate experimental analyses. In this work, the author solves this technical hurdle by producing ultracold cesium atoms in a quasi-2D optical box potential. The exquisite optical trap allows one to remove density inhomogeneity in a degenerate quantum gas and control its dimensionality. The author also details the development of a high-resolution, in situ imaging technique to monitor the evolution of collective excitations and quantum transport down to atomic shot-noise, and at the length scale of elementary collective excitations. Meanwhile, tunable Feshbach resonances in ultracold cesium atoms permit precise and dynamical control of interactions with high temporal and even spatial resolutions. By employing these state-of-the-art techniques, the author performed interaction quenches to control the generation and evolution of quasiparticles in quantum gases, presenting the first direct measurement of quantum entanglement between interaction quench generated quasiparticle pairs in an atomic superfluid. Quenching to attractive interactions, this work shows stimulated emission of quasiparticles, leading to amplified density waves and fragmentation, forming 2D matter-wave Townes solitons that were previously considered impossible to form in equilibrium due to their instability. This thesis unveils a set of scale-invariant and universal quench dynamics and provides unprecedented tools to explore quantum entanglement transport in a homogenous quantum gas.

The book has been designed as a textbook for graduate and postgraduate students of physics, material science, and engineering. This is the third edition of the textbook, that is updated to reflect recent works in the field. In this edition, some new topics have been introduced while some of the existing topics like phonons, Drude -Lorentz model, Fermi levels, electrons, and holes, etc. are modified. Moreover, the book has complete information on semiconductor devices like tunnel diode, Gunn diode, photodiode, photoconductive diode, varactor diode, solar cell, LED, semiconductor lasers, and semiconductor detectors. All the chapters have been supplemented by solved and unsolved examples. Some of the chapters illustrate areas of current interest in solid-state physics to give the student practical working knowledge of the subject text in a simple and lucid manner. There is a fair amount of detail in the examples and derivations given in the text. Each section of the book has exercises to reinforce the concepts, and problems have been added at the end of each chapter. The detailed coverage and pedagogical tools make this an ideal textbook for students and researchers enrolled in graduate and postgraduate courses of physics, material science, and engineering.

This book features selected articles based on contributions presented at the 9th International Symposium on Optics and Its Applications (OPTICS-2022) in Yerevan-Ashtarak, Armenia. The annual OPTICS symposium brings together renowned experts from all over the world working in the fields of atomic optics, plasmonics, optics of nanostructures, as well as the optics of condensed matter, and provides a perfect setting for their discussions of the most recent developments in this area.The 9th iteration in this series, dedicated to the 80th birthday of Academician Eduard Kazaryan, focuses on topics dealing with the spectroscopy of real and artificial atoms, linear and nonlinear optical characteristics of quantum wells, and two-dimensional materials. The book highlights recent results of few-particle optical characteristics of artificial atoms in the framework of the exactly solvable Moshinsky model, as well as an electro-optical analog of the magneto-optical Faraday effect. In addition, a detailed study of the nucleation process, its characterization, as well as electronic and optical properties of graded composition quantum dots in the StranskiKrastanov growth mode, is presented.

This proceedings volume gathers selected, peer-reviewed papers presented at the 41st International Conference on Infinite Dimensional Analysis, Quantum Probability and Related Topics (QP41) that was virtually held at the United Arab Emirates University (UAEU) in Al Ain, Abu Dhabi, from March 28th to April 1st, 2021. The works cover recent developments in quantum probability and infinite dimensional analysis, with a special focus on applications to mathematical physics and quantum information theory. Covered topics include white noise theory, quantum field theory, quantum Markov processes, free probability, interacting Fock spaces, and more. By emphasizing the interconnection and interdependence of such research topics and their real-life applications, this reputed conference has set itself as a distinguished forum to communicate and discuss new findings in truly relevant aspects of theoretical and applied mathematics, notably in the field of mathematical physics, as well as an event of choice for the promotion of mathematical applications that address the most relevant problems found in industry. That makes this volume a suitable reading not only for researchers and graduate students with an interest in the field but for practitioners as well.