This book presents theoretical methods and experimental results on the study of multipartite quantum correlations in spin-squeezed Bose-Einstein condensates. Nonclassical correlations in many-body system s are particularly interesting for both fundamental research and practical applications. For their investigation, ultracold atomic ensembles offer an ideal platform, due to their high controllability and long coherence times. In particular, we introduce criteria for detecting and characterizing multipartite entanglement, Einstein-Podolsky-Rosen steering, and Bell correlations. Moreover, we present the experimental observation of such correlations in systems of about 600 atoms.

Tau functions are a central tool in the modern theory of integrable systems. This volume provides a thorough introduction, starting from the basics and extending to recent research results. It covers a wide range of applications, including generating functions for solutions of integrable hierarchies, correlation functions in the spectral theory of random matrices and combinatorial generating functions for enumerative geometrical and topological invariants. A self-contained summary of more advanced topics needed to understand the material is provided, as are solutions and hints for the various exercises and problems that are included throughout the text to enrich the subject matter and engage the reader. Building on knowledge of standard topics in undergraduate mathematics and basic concepts and methods of classical and quantum mechanics, this monograph is ideal for graduate students and researchers who wish to become acquainted with the full range of applications of the theory of tau functions.

NAMED A BEST BOOK OF THE YEAR BY THE ECONOMIST, OBSERVER, NEW SCIENTIST, BBC FOCUS, INDEPENDENT AND WASHINGTON POST 'A rollicking tour of the wildest physics. . . Like an animated discussion with your favourite quirky and brilliant professor' Leah Crane, New Scientist 'Weird science, explained beautifully' - John Scalzi We know the universe had a beginning. But what happens at the end of the story? With lively wit and wry humour, astrophysicist Katie Mack takes us on a mind-bending tour through each of the cosmos' possible finales: the Big Crunch, Heat Death, Vacuum Decay, the Big Rip and the Bounce. Guiding us through major concepts in quantum mechanics, cosmology, string theory and much more, she describes how small tweaks to our incomplete understanding of reality can result in starkly different futures. Our universe could collapse in upon itself, or rip itself apart, or even - in the next five minutes - succumb to an inescapable expanding bubble of doom. This captivating story of cosmic escapism examines a mesmerizing yet unfamiliar physics landscape while sharing the excitement a leading astrophysicist feels when thinking about the universe and our place in it. Amid stellar explosions and bouncing universes, Mack shows that even though we puny humans have no chance of changing how it all ends, we can at least begin to understand it. The End of Everything is a wildly fun, surprisingly upbeat ride to the farthest reaches of all that we know.

This thesis proposes a new perspective on scattering amplitudes in quantum field theories. Their standard formulation in terms of sums over Feynman diagrams is replaced by a computation of geometric invariants, called intersection numbers, on moduli spaces of Riemann surfaces. It therefore gives a physical interpretation of intersection numbers, which have been extensively studied in the mathematics literature in the context of generalized hypergeometric functions. This book explores physical consequences of this formulation, such as recursion relations, connections to geometry and string theory, as well as a phenomenon called moduli space localization. After reviewing necessary mathematical background, including topology of moduli spaces of Riemann spheres with punctures and its fundamental group, the definition and properties of intersection numbers are presented. A comprehensive list of applications and relations to other objects is given, including those to scattering amplitudes in open- and closed-string theories. The highlights of the thesis are the results regarding localization properties of intersection numbers in two opposite limits: in the low- and the high-energy expansion. In order to facilitate efficient computations of intersection numbers the author introduces recursion relations that exploit fibration properties of the moduli space. These are formulated in terms of so-called braid matrices that encode the information of how points braid around each other on the corresponding Riemann surface. Numerous application of this approach are presented for computation of scattering amplitudes in various gauge and gravity theories. This book comes with an extensive appendix that gives a pedagogical introduction to the topic of homologies with coefficients in a local system.

Advancing the experimental study of superfluids relies on increasingly sophisticated techniques. We develop and demonstrate the loading of Bose-Einstein condensates (BECs) into nearly arbitrary trapping potentials, with a resolution improved by a factor of seven when compared to reported systems. These advanced control techniques have since been adopted by several cold atoms labs around the world. How this BEC system was used to study 2D superfluid dynamics is described. In particular, negative temperature vortex states in a two-dimensional quantum fluid were observed. These states were first predicted by Lars Onsager 70 years ago and have significance to 2D turbulence in quantum and classical fluids, long-range interacting systems, and defect dynamics in high-energy physics. These experiments have established dilute-gas BECs as the prototypical system for the experimental study of point vortices and their nonequilibrium dynamics. We also developed a new approach to superfluid circuitry based on classical acoustic circuits, demonstrating its conceptual and quantitative superiority over previous lumped-element models. This has established foundational principles of superfluid circuitry that will impact the design of future transport experiments and new generation quantum devices, such as atomtronics circuits and superfluid sensors.

The book highlights the personal and scientific struggles of Arthur Erich Haas (1884-1941), an Austrian Physicist from a wealthy Jewish middle-class family, whose remarkable accomplishments in a politically hostile but scientifically rewarding environment deserve greater recognition. Haas was a fellow student of both Lise Meitner and Erwin Schroedinger and was also one of the last doctoral students of Ludwig Boltzmann. Following Boltzmann's suicide, Haas was forced to submit a more independent doctoral thesis in which he postulated new approaches in early quantum theory, actually introducing the idea of the Bohr radius before Niels Bohr. It is the lost story of a trailblazer in the fields of quantum mechanics and cosmology, a herald of nuclear energy and applications of modern science. This biography of Haas is based on new and previously unpublished family records and archived material from the Vienna Academy of Science and the University of Notre Dame, which the author has collected over many years. From his analysis of the letters, documents, and photos that rested for nearly a century in family attics and academic archives, Michael Wiescher provides a unique and detailed insight into the life of a gifted Jewish physicist during the first half of the twentieth century. It also sheds light on the scientific developments and thinking of the time. It appeals not only to historians and physicists, but also general readers. All appreciate the record of Haas' interactions with many of the key figures who helped to found modern physics.

This book seeks to present a new way of thinking about the interaction of gravitational fields with quantum systems. Despite the massive amounts of research and experimentation, the myriad meetings, seminars and conferences, all of the articles, treatises and books, and the seemingly endless theorization, quantization and just plain speculation that have been engaged in regarding our evolving understanding of the quantum world, that world remains an enigma, even to the experts. The usefulness of general relativity in this regard has proven to be imperfect at best, but there is a new approach. We do not simply have to accept the limitations of Einstein's most celebrated theorem in regard to quantum theory; we can also embrace them, and thereby utilize them, to reveal new facts about the behavior of quantum systems within inertial and gravitational fields, and therefore about the very structure of space-time at the quantum level. By taking existing knowledge of the essential functionality of spin (along with the careful identification of the omnipresent inertial effects) and applying it to the quantum world, the book gives the reader a much clearer picture of the difference between the classical and quantum behaviors of a particle, shows that Einstein's ideas may not be as incompatible within this realm as many have come to believe, sparks new revelations of the way in which gravity affects quantum systems and brings a new level of efficiency-quantum efficiency, if you will-to the study of gravitational theory.

This book provides an itinerary to quantum mechanics taking into account the basic mathematics to formulate it. Specifically, it features the main experiments and postulates of quantum mechanics pointing out their mathematical prominent aspects showing how physical concepts and mathematical tools are deeply intertwined. The material covers topics such as analytic mechanics in Newtonian, Lagrangian, and Hamiltonian formulations, theory of light as formulated in special relativity, and then why quantum mechanics is necessary to explain experiments like the double-split, atomic spectra, and photoelectric effect. The Schroedinger equation and its solutions are developed in detail. It is pointed out that, starting from the concept of the harmonic oscillator, it is possible to develop advanced quantum mechanics. Furthermore, the mathematics behind the Heisenberg uncertainty principle is constructed towards advanced quantum mechanical principles. Relativistic quantum mechanics is finally considered.The book is devoted to undergraduate students from University courses of Physics, Mathematics, Chemistry, and Engineering. It consists of 50 self-contained lectures, and any statement and theorem are demonstrated in detail. It is the companion book of "A Mathematical Journey to Relativity", by the same Authors, published by Springer in 2020.

This textbook is a unique and ambitious primer of nuclear physics, which introduces recent theoretical and experimental progresses starting from basics in fundamental quantum mechanics. The highlight is to offer an overview of nuclear structure phenomena relevant to recent key findings such as unstable halo nuclei, superheavy elements, neutron stars, nucleosynthesis, the standard model, lattice quantum chromodynamics (LQCD), and chiral effective theory. An additional attraction is that general properties of nuclei are comprehensively explained from both the theoretical and experimental viewpoints. The book begins with the conceptual and mathematical basics of quantum mechanics, and goes into the main point of nuclear physics - nuclear structure, radioactive ion beam physics, and nuclear reactions. The last chapters devote interdisciplinary topics in association with astrophysics and particle physics. A number of illustrations and exercises with complete solutions are given. Each chapter is comprehensively written starting from fundamentals to gradually reach modern aspects of nuclear physics with the objective to provide an effective description of the cutting edge in the field.

The path integral approach has proved extremely useful for the understanding of the most complex problems in quantum field theory, cosmology, and condensed matter physics. Path Integrals in Physics: Volume II, Quantum Field Theory, Statistical Physics and other Modern Applications covers the fundamentals of path integrals, both the Wiener and Feynman types, and their many applications in physics. The book deals with systems that have an infinite number of degrees of freedom. It discusses the general physical background and concepts of the path integral approach used, followed by a detailed presentation of the most typical and important applications as well as problems with either their solutions or hints how to solve them. Each chapter is self-contained and can be considered as an independent textbook. It provides a comprehensive, detailed, and systematic account of the subject suitable for both students and experienced researchers.

This thesis demonstrates the potential of two platforms to explore experimentally the emerging field of quantum thermodynamics that has remained mostly theoretical so far. It proposes methods to define and measure work in the quantum regime. The most important part of the thesis focuses on hybrid optomechanical devices, evidencing that they are proper candidates to measure directly the fluctuations of work and the corresponding fluctuation theorem. Such devices could also give rise to the observation of mechanical lasing and cooling, based on mechanisms similar to a heat engine. The final part of the thesis studies how quantum coherence can improve work extraction in superconducting circuits. All the proposals greatly clarify the concept of work since they are based on measurable quantities in state of the art devices.

This book presents a comprehensive overview of state-of-the-art quantum dot photodetectors, including device fabrication technologies, optical engineering/manipulation strategies, and emerging photodetectors with building blocks of novel quantum dots (e.g. perovskite) as well as their hybrid structured (e.g. 0D/2D) materials. Semiconductor quantum dots have attracted much attention due to their unique quantum confinement effect, which allows for the facile tuning of optical properties that are promising for next-generation optoelectronic applications. Among these remarkable properties are large absorption coefficient, high photosensitivity, and tunable optical spectrum from ultraviolet/visible to infrared region, all of which are very attractive and favorable for photodetection applications. The book covers both fundamental and frontier research in order to stimulate readers' interests in developing novel ideas for semiconductor photodetectors at the center of future developments in materials science, nanofabrication technology and device commercialization. The book provides a knowledge sharing platform and can be used as a reference for researchers working in the fields of photonics, materials science, and nanodevices.

This book presents research contributions focussing on the introduction of contemporary physics topics - mainly, but not exclusively, quantum physics - into high school currciula. Despite the important advances and discoveries in quantum physics and relativity which have revolutionized our views of nature and our everyday lives, the presence of these topics in high school physics education is still lacking. In this book physics education researchers report on the teaching and learning of quantum physics from different perspectives and discuss the design and use of different pedagogical approaches and educational pathways. There is still much debate as to what content is appropriate at high school level as well what pedagogical approaches and strategies should be adopted to support student learning. Currently there is a greater focus on how to teach modern physics at the high school level rather than classical physics. However, teachers still lack experience and availability of appropriate teaching and learning materials to support the coherent integration of Quantum Physics in high school curricula. All of the 19 papers presented in this book discuss innovative approaches for enhancing physics education in schools.

This work covers quantum mechanics by answering questions such as where did the Planck constant and Heisenberg algebra come from, what motivated Feynman to introduce his path integral and why does one distinguish two types of particles, the bosons and fermions. The author addresses all these topics with utter mathematical rigor. The high number of instructive Appendices and numerous Remark sections supply the necessary background knowledge.

This thesis reports the calculation of neutrino production for the T2K experiment; the most precise a priori estimate of neutrino production that has been achieved for any accelerator-based neutrino oscillation experiment to date. The production of intense neutrino beams at accelerator facilities requires exceptional understanding of chains of particle interactions initiated within extended targets. In this thesis, the calculation of neutrino production for T2K has been improved by using measurements of particle production from a T2K replica target, taken by the NA61/SHINE experiment. This enabled the reduction of the neutrino production uncertainty to the level of 5%, which will have a significant impact on neutrino oscillation and interaction measurements by T2K in the coming years. In addition to presenting the revised flux calculation methodology in an accessible format, this thesis also reports a joint T2K measurement of muon neutrino and antineutrino disappearance, and the accompanying electron neutrino and antineutrino appearance, with the updated beam constraint.

This new edition of a well-received textbook provides a concise introduction to both the theoretical and experimental aspects of quantum information at the graduate level. While the previous edition focused on theory, the book now incorporates discussions of experimental platforms. Several chapters on experimental implementations of quantum information protocols have been added: implementations using neutral atoms, trapped ions, optics, and solidstate systems are each presented in its own chapter. Previous chapters on entanglement, quantum measurements, quantum dynamics, quantum cryptography, and quantum algorithms have been thoroughly updated, and new additions include chapters on the stabilizer formalism and the Gottesman-Knill theorem as well as aspects of classical and quantum information theory. To facilitate learning, each chapter starts with a clear motivation to the topic and closes with exercises and a recommended reading list. Quantum Information Processing: Theory and Implementation will be essential to graduate students studying quantum information as well as and researchers in other areas of physics who wish to gain knowledge in the field.

This PhD thesis documents two of the highest-profile searches for supersymmetry performed at the ATLAS experiment using up to 80/fb of proton-proton collision data at a center-of-mass energy of 13 TeV delivered by the Large Hadron Collider (LHC) during its Run 2 (2015-2018). The signals of interest feature a high multiplicity of jets originating from the hadronisation of b-quarks and large missing transverse momentum, which constitutes one of the most promising final state signatures for discovery of new phenomena at the LHC. The first search is focused on the strong production of a pair of gluinos, with each gluino decaying into a neutralino and a top-antitop-quark pair or a bottom-antibottom-quark pair. The second search targets the pair production of higgsinos, with each higgsino decaying into a gravitino and a Higgs boson, which in turn is required to decay into a bottom-antibottom-quark pair. Both searches employ state-of-the-art experimental techniques and analysis strategies at the LHC, resulting in some of the most restrictive bounds available to date on the masses of the gluino,neutralino, and higgsino in the context of the models explored.

This book is devoted to advanced materials and perspective sensors, which is one of the most important problems in nanotechnology and security. This book is useful for researchers, scientist and graduate students in the fields of solid state physics, nanotechnology and security.

This book reveals unique transport phenomena and functionalities in topological insulators coupled with magnetism and superconductivity. Topological insulators are a recently discovered class of materials that possess a spin-momentum-locked surface state. Their exotic spin texture makes them an exciting platform for investigating emergent phenomena, especially when coupled with magnetism or superconductivity. Focusing on the strong correlation between electricity and magnetism in magnetic topological insulators, the author presents original findings on current-direction-dependent nonreciprocal resistance, current-induced magnetization reversal and chiral edge conduction at the domain wall. In addition, he demonstrates how the coupling between superconductivity and topological surface state leads to substantial nonreciprocal resistance. The author also elucidates the origins of these phenomena and deepens readers' understanding of the topologically nontrivial electronic state. The book includes several works which are published in top journals and were selected for the President's Award by the University of Tokyo and for the Ikushi Prize, awarded to distinguished Ph.D. students in Japan.

This book gives a general introduction to theoretically understand thermodynamic properties and response to applied fields of mesoscopic systems that closely relate to experiments. The book clarifies many conceptual and practical problems associated with the Larmor clock and thus makes it a viable approach to study these properties. The book is written pedagogically so that a graduate or undergraduate student can follow it. This book also opens up new research areas related to the unification of classical and quantum theories and the meaning of time. It provides a scientific mechanism for time travel which is of immense fascination to science as well as society. It is known that developments in mesoscopic physics can lead to downscaling of device sizes. So, new or experienced researchers can have a quick introduction to various areas in which they might contribute in the future. This book is expected to be a valuable addition to the subject of mesoscopic physics.

Following Witten's remarkable discovery of the quantum mechanical scheme in which all the salient features of supersymmetry are embedded, SCQM (supersymmetric classical and quantum mechanics) has become a separate area of research . In recent years, progress in this field has been dramatic and the literature continues to grow. Until now, no book has offered an overview of the subject with enough detail to allow readers to become rapidly familiar with its key ideas and methods.

Supersymmetry in Classical and Quantum Mechanics offers that overview and summarizes the major developments of the last 15 years. It provides both an up-to-date review of the literature and a detailed exposition of the underlying SCQM principles. For those just beginning in the field, the author presents step-by-step details of most of the computations. For more experienced readers, the treatment includes systematic analyses of more advanced topics, such as quasi- and conditional solvability and the role of supersymmetry in nonlinear systems.

Quantum systems with many degrees of freedom are inherently difficult to describe and simulate quantitatively. The space of possible states is, in general, exponentially large in the number of degrees of freedom such as the number of particles it contains. Standard digital high-performance computing is generally too weak to capture all the necessary details, such that alternative quantum simulation devices have been proposed as a solution. Artificial neural networks, with their high non-local connectivity between the neuron degrees of freedom, may soon gain importance in simulating static and dynamical behavior of quantum systems. Particularly promising candidates are neuromorphic realizations based on analog electronic circuits which are being developed to capture, e.g., the functioning of biologically relevant networks. In turn, such neuromorphic systems may be used to measure and control real quantum many-body systems online. This thesis lays an important foundation for the realization of quantum simulations by means of neuromorphic hardware, for using quantum physics as an input to classical neural nets and, in turn, for using network results to be fed back to quantum systems. The necessary foundations on both sides, quantum physics and artificial neural networks, are described, providing a valuable reference for researchers from these different communities who need to understand the foundations of both.

The relaxation of isolated quantum many-body systems is a major unsolved problem of modern physics, which is connected to many fundamental questions. However, realizations of quantum many-body systems which are both well isolated from their environment and accessible to experimental study are scarce. In recent years, the field has experienced rapid progress, partly attributed to ultra-cold atoms. This book presents the experimental study of a relaxation phenomenon occurring in a one-dimensional bosonic Josephson junction. The system consists of two 1D quasi Bose-Einstein condensates of 87Rb, magnetically trapped on an atom chip. Using radio-frequency dressing, the author deforms a single harmonic trap, in which the atoms are initially condensed, into a double-well potential and realizes a splitting of the wave function. A large spatial separation and a tilt of the double-well enable the preparation of a broad variety of initial states by precisely adjusting the initial population and relative phase of the two wave packets, while preserving the phase coherence. By re-coupling the two wave packets, the author investigates tunneling regimes such as Josephson (plasma) oscillations and macroscopic quantum self-trapping. In both regimes, the tunneling dynamics exhibits a relaxation to a phase-locked equilibrium state contradicting theoretical predictions. The experimental results are supported with an empirical model that allows quantitative discussions according to various experimental parameters. These results illustrate how strongly the non-equilibrium dynamics differ from the equilibrium one, which is well described by thermodynamics and statistical physics.

This thesis focuses on searches for squarks with the ATLAS detector in "compressed" scenarios where the scalar top is very close in mass to the lightest supersymmetric particle. These models are theoretically appealing because the presence of a quasi-degenerate scalar top enhances the self-annihilation cross-section of the lightest supersymmetric particle, acting therefore as a regulator of the dark matter relic density. Two main analyses are presented: the first is a search for scalar tops decaying to charm quarks. The identification of jets originating from the charm quark is very challenging due to its short lifetime. The calibration of tools for charm-tagging has paved the way to measuring the decay of the Higgs boson to pairs of charm quarks. The second analysis presented is the development of a novel technique for reconstructing low momentum b-hadrons. This tool has enabled the ATLAS collaboration to explore topologies that were previously inaccessible.

This thesis presents a revolutionary technique for modelling the dynamics of a quantum system that is strongly coupled to its immediate environment. This is a challenging but timely problem. In particular it is relevant for modelling decoherence in devices such as quantum information processors, and how quantum information moves between spatially separated parts of a quantum system. The key feature of this work is a novel way to represent the dynamics of general open quantum systems as tensor networks, a result which has connections with the Feynman operator calculus and process tensor approaches to quantum mechanics. The tensor network methodology developed here has proven to be extremely powerful: For many situations it may be the most efficient way of calculating open quantum dynamics. This work is abounds with new ideas and invention, and is likely to have a very significant impact on future generations of physicists.