This book is a thoroughly modern and highly pedagogical graduate-level introduction to quantum optics, a subject which has witnessed stunning developments in recent years and has come to occupy a central role in the 'second quantum revolution'. The reader is invited to explore the fundamental role that quantum optics plays in the control and manipulation of quantum systems, leading to ultracold atoms, circuit QED, quantum information science, quantum optomechanics, and quantum metrology. The building blocks of the subject are presented in a sequential fashion, starting from the simplest physical situations before moving to increasingly complicated ones. This pedagogically appealing approach leads to quantum entanglement and measurement theory being introduced early on and before more specialized topics such as cavity QED or laser cooling. The final chapter illustrates the power of scientific cross-fertilization by surveying cutting-edge applications of quantum optics and optomechanics in gravitational wave detection, tests of fundamental physics, searches for dark matter, geophysical monitoring, and ultraprecise clocks. Complete with worked examples and exercises, this book provides the reader with enough background knowledge and understanding to follow the current journal literature and begin producing their own original research.

This thesis presents the first ever measurement of the noise emitted by magnetic monopoles and the development of an exquisitely sensitive magnetic-field-noise spectrometer based on a superconducting quantum interference device (SQUID) that enabled it. Magnetic monopoles are highly elusive elementary particles exhibiting quantized magnetic charge. The prospects for studying them brightened recently with the theoretical discovery that the thermally excited states in certain classes of magnetic insulators exhibit all the characteristics of magnetic monopoles. Furthermore, in 2018, it was predicted that the random motion of magnetic monopoles inside would generate a very specific kind of magnetization noise. In this thesis, the author describes a new experimental technique, so-called spin noise spectroscopy, and the subsequent discovery of virtually all of the predicted features of the magnetic noise expected from a dense fluid of magnetic monopoles in crystals of Dy2Ti2O7. Remarkably, because this magnetic monopole noise occurs in the frequency range below 20kHz, when amplified by the SQUID it is actually audible to humans.

This book presents the basics of superconductivity and applications of superconducting magnets. It explains the phenomenon of superconductivity, describes theories of superconductivity, and discusses type II and high-temperature cuprate superconductors. The main focus of the book is the application of superconducting magnets in accelerators, fusion reactors and other advanced applications such as nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), high-gradient magnetic separation (HGMS), and superconducting magnetic energy storage (SMES). This new and significantly extended second edition covers the state of the art in the development of novel superconductors for advanced magnet applications, as well as the production of practical superconducting wires, tapes, and ultra high current cables used for high-field magnets. It includes two new chapters each devoted to MgB2 and Fe-based superconductors, and discusses the recently developed and world record-setting 45.5-Tesla magnetic field generated by a combination of conventional and high-temperature cuprate superconducting magnets. In addition, it discusses the status and outlook of all current and future nuclear fusion reactors worldwide. The chapter on accelerators includes the ongoing efforts to build high luminosity LHC (HL-LHC), the high-energy 28 TeV LHC (HE-LHC), the future circular collider (FCC) at CERN, and the just launched electro-ion collider (EIC) at Brookhaven National Laboratory. The book is based on the long-standing experience of the author in studying superconducting materials, building magnets and delivering numerous lectures to research scholars and students. The book provides comprehensive and fundamental knowledge in the field of applied superconductivity, greatly benefiting researchers and graduate students wishing to learn more about the various aspects of superconductivity and advanced magnet applications.

This book offers a practical introduction to helium refrigeration engineering, taking a logical and structured approach to the design, building, commissioning, operation and maintenance of refrigeration systems. It begins with a short refresher of cryogenic principles, and a review of the theory of heat exchangers, allowing the reader to understand the importance of the heat exchanger role in the various thermodynamic cycle structures. The cycles are considered from the simplest (Joule Thomson) to the most complicated ones for the very large refrigeration plants and, finally, those operating at temperatures lower than 4.5 K. The focus then turns to the operation, ability and limitations of the main components, including room temperature cycle screw compressors, heat exchangers, cryogenic expansion turbines, cryogenic centrifugal compressors and circulators. The book also describes the basic principles of process control and studies the operating situations of helium plants, with emphasis on high level efficiency. A major issue is helium purity, and the book explains why helium is polluted, how to purify it and then how to check its purity, to ensure that all components are filled with pure helium prior to starting. Although the intention of the book is not to design thermodynamic cycles, it is of interest to a designer or operator of a cryogenic system to perform some simplified calculations to get an idea of how components or systems are behaving. Throughout the book, such calculations are generally performed using Microsoft (R) Excel and the Gaspak (R) or Hepak (R) software.

This book introduces readers to the characteristic features of electromagnetic phenomena in superconductivity. It first demonstrates not only that the diamagnetism in the superconductivity complies with Maxwell's theory, which was formulated before the discovery of superconductivity, but also that the dominant E-B analogy in the electromagnetism loses perfection without the superconductivity. The book then explores flux pinning, which is responsible for the non-dissipative current in DC, leading to irreversibility in AC. Drawing on Maxwell's work, it also proves theoretically that if there is no energy dissipation in the superconductivity caused by the break in time reversal symmetry, it contradicts the thermodynamic principle of energy conservation - something that had previously only been proved experimentally. Lastly, the book addresses the longitudinal magnetic field effect, and explains how this phenomenon leads to a new development of Maxwell's theory. Featuring numerous appendices to help readers understand the methods of derivation of equations, this book offers students and young scientists an introduction to applied superconductivity, especially in the context of power applications. Presenting the characteristic features of electromagnetic phenomena in superconductivity from basic to advanced topics for applications, the book offers a valuable resource for graduate students and researchers studying superconductivity as well as engineers working in electric utility industry.

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.

This book offers a comprehensive overview of thermodynamics. It is divided into four parts, the first of which equips readers with a deeper understanding of the fundamental principles of thermodynamics of equilibrium states and of their evolution. The second part applies these principles to a series of generalized situations, presenting applications that are of interest both in their own right and in terms of demonstrating how thermodynamics, as a theory of principle, relates to different fields. In turn, the third part focuses on non-equilibrium configurations and the dynamics of natural processes. It discusses both discontinuous and continuous systems, highlighting the interference among non-equilibrium processes, and the nature of stationary states and of fluctuations in isolated systems. Lastly, part four introduces the relation between physics and information theory, which constitutes a new frontier in fundamental research. The book includes step-by-step exercises, with solutions, to help readers to gain a fuller understanding of the subjects, and also features a series of appendices providing useful mathematical formulae. Reflecting the content of modern university courses on thermodynamics, it is a valuable resource for students and young scientists in the fields of physics, chemistry, and engineering.

The nature of dark matter remains one of the preeminent mysteries in physics and cosmology. It appears to require the existence of new particles whose interactions with ordinary matter are extraordinarily feeble. One well-motivated candidate is the axion, an extraordinarily light neutral particle that may possibly be detected by looking for their conversion to detectable microwaves in the presence of a strong magnetic field. This has led to a number of experimental searches that are beginning to probe plausible axion model space and may reveal the axion in the near future. These proceedings discuss the challenges of designing and operating tunable resonant cavities and detectors at ultralow temperatures. The topics discussed here have potential application far beyond the field of dark matter detection and may be applied to resonant cavities for accelerators as well as designing superconducting detectors for quantum information and computing applications. This work is intended for graduate students and researchers interested in learning the unique requirements for designing and operating microwave cavities and detectors for direct axion searches and to introduce several proposed experimental concepts that are still in the prototype stage.

This thesis explores several fundamental topics in mesoscopic circuitries that incorporate few electronic conduction channels. It reports a series of long-awaited experiments that establish a new state of the art. The first experiments address the quantized character of charge in circuits. We demonstrate the charge quantization criterion, observe the predicted charge quantization scaling and a crossover toward a universal behavior as temperature is increased. The second set of experiments addresses the unconventional quantum critical physics that arises in the multichannel Kondo model. We observe the predicted universal Kondo fixed points and validate the numerical renormalization group scaling curves. Away from the quantum critical point, we obtain a direct visualization of the development of a second-order quantum phase transition.

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.

In this thesis, ultimate sensitive measurement for weak force imposed on a suspended mirror is performed with the help of a laser and an optical cavity for the development of gravitational-wave detectors. According to the Heisenberg uncertainty principle, such measurements are subject to a fundamental noise called quantum noise, which arises from the quantum nature of a probe (light) and a measured object (mirror). One of the sources of quantum noise is the quantum back-action, which arises from the vacuum fluctuation of the light. It sways the mirror via the momentum transferred to the mirror upon its reflection for the measurement. The author discusses a fundamental trade-off between sensitivity and stability in the macroscopic system, and suggests using a triangular cavity that can avoid this trade-off. The development of an optical triangular cavity is described and its characterization of the optomechanical effect in the triangular cavity is demonstrated. As a result, for the first time in the world the quantum back-action imposed on the 5-mg suspended mirror is significantly evaluated. This work contributes to overcoming the standard quantum limit in the future.

In this thesis, the author investigates hidden-order phase transition at" T"0 = 17.5 K in the heavy-fermion URu2Si2. The four-fold rotational symmetry breaking in the hidden order phase, which imposes a strong constraint on the theoretical model, is observed through the magnetic torque measurement. The translationally invariant phase with broken rotational symmetry is interpreted as meaning that the hidden-order phase is an electronic "nematic" phase. The observation of such nematicity in URu2Si2 indicates a ubiquitous nature among the strongly correlated electron systems.

The author also studies the superconducting state of URu2Si2 below" T"c = 1.4 K, which coexists with the hidden-order phase. A peculiar vortex penetration in the superconducting state is found, which may be related to the rotational symmetry breaking in the hidden-order phase. The author also identifies a vortex lattice melting transition. This transport study provides essential clues to the underlying issue of quasiparticle dynamics as to whether a quasiparticle Bloch state is realized in the periodic vortex lattice.

This thesis represents a decisive breakthrough in our understanding of the physics of universal quantum-mechanical three-body systems. The Efimov scenario is a prime example of how fundamental few-body physics features universally across seemingly disparate fields of modern quantum physics. Initially postulated for nuclear physics more than 40 years ago, the Efimov effect has now become a new research paradigm not only in ultracold atomic gases but also in molecular, biological and condensed matter systems. Despite a lot of effort since its first observations, the scaling behavior, which is a hallmark property and often referred to as the "holy grail" of Efimov physics, remained hidden until recently. In this work, the author demonstrates this behavior for the first time for a heteronuclear mixture of ultracold Li and Cs atoms, and pioneers the experimental understanding of microscopic, non-universal properties in such systems. Based on the application of Born-Oppenheimer approximation, well known from molecular physics textbooks, an exceptionally clear and intuitive picture of heteronuclear Efimov physics is revealed.

This highly interdisciplinary thesis covers a wide range of topics relating to the interface of cold atoms, quantum simulation, quantum magnetism and disorder. With a self-contained presentation, it provides a broad overview of the rapidly evolving area of cold atoms and is of interest to both undergraduates and researchers working in the field. Starting with a general introduction to the physics of cold atoms and optical lattices, it extends the theory to that of systems with different multispecies atoms. It advances the theory of many-body quantum systems in excited bands (of optical lattices) through an extensive study of the properties of both the mean-field and strongly correlated regimes. Particular emphasis is given to the context of quantum simulation, where as shown here, the orbital degree of freedom in excited bands allows the study of exotic models of magnetism not easily achievable with the previous alternative systems. In addition, it proposes a new model Hamiltonian that serves as a quantum simulator of various disordered systems in different symmetry classes that can easily be reproduced experimentally. This is of great interest, especially for the study of disorder in 2D quantum systems.

In the past decade, there has been a burst of new and fascinating physics associated to the unique properties of two-dimensional exciton polaritons, their recent demonstration of condensation under non-equilibrium conditions and all the related quantum phenomena, which have stimulated extensive research work. This monograph summarizes the current state of the art of research on exciton polaritons in microcavities: their interactions, fast dynamics, spin-dependent phenomena, temporal and spatial coherence, condensation under non-equilibrium conditions, related collective quantum phenomena and most advanced applications. The monograph is written by the most active authors who have strongly contributed to the advances in this area. It is of great interests to both physicists approaching this subject for the first time, as well as a wide audience of experts in other disciplines who want to be updated on this fast moving field.

This thesis demonstrates that an ultralow temperature refrigeration technique called "demagnetisation refrigeration" can be miniaturised and incorporated onto millimeter-sized chips to cool nanoelectronic circuits, devices and materials. Until recently, the lowest temperature ever reached in such systems was around 4 millikelvin. Here, a temperature of 1.2mK is reported in a nanoelectronic device. The thesis introduces the idea that on-chip demagnetization refrigeration can be used to cool a wide variety of nanostructures and devices to microkelvin temperatures. This brings the exciting possibility of discovering new physics, such as exotic electronic phases, in an unexplored regime and the potential to improve the performance of existing applications, including solid-state quantum technologies. Since the first demonstration of on-chip demagnetization refrigeration, described here, the technique has been taken up by other research groups around the world. The lowest on-chip temperature is currently 0.4mK. Work is now underway to adapt the technique to cool other materials and devices, ultimately leading to a platform to study nanoscale materials, devices and circuits at microkelvin temperatures.

The field of superconductivity has tremendous potential for growth and further development in industrial applications. The subject continues to occupy physicists, chemists, and engineers interested in both the phenomena itself and possible financially viable industrial devices utilizing the physical concepts. For the past five years, within the publications of the American Physical Society, for example, 40%-60% of all articles submitted to major journals in the area of Solid State Physics have been on the subject of superconductivity, including the newer, extremely important subfield of high temperature superconductivity (high Tc).
The present volume is the first handbook to address this field. It covers both "classic" superconductivity-related topics and high Tc. Numerous properties, including thermal, electrical, magnetic, mechanical, phase diagrams, and spectroscopic crystallographic structures are presented for many types of superconductors. Critical fields, critical currents, coherence lengths, penetration depths, and transition temperatures are tabulated.
Key Features
* First handbook on Superconductivity
* Coherence lengths and depths are tabulated
* Crystallographic structures of over 100 superconductor types
* Main results of several theories are submitted
* Phase diagrams for synthesizing new
superconductors are included

This book presents the current knowledge about superconductivity in high Tc cuprate superconductors. There is a large scientific interest and great potential for technological applications. The book discusses all the aspects related to all families of cuprate superconductors discovered so far. Beginning with the phenomenon of superconductivity, the book covers: the structure of cuprate HTSCs, critical currents, flux pinning, synthesis of HTSCs, proximity effect and SQUIDs, possible applications of high Tc superconductors and theories of superconductivity. Though a high Tc theory is still awaited, this book describes the present scenario and BCS and RVB theories. The second edition was significantly extended by including film-substrate lattice matching and buffer layer considerations in thin film HTSCs, brick-wall microstructure in the epitaxial films, electronic structure of the CuO2 layer in cuprates, s-wave and d-wave coupling in HTSCs and possible scenarios of theories of high Tc superconductivity.

The study of quantum fluids, stimulated by the discovery of superfluidity in liquid helium, has experienced renewed interest after the observation of Bose-Einstein condensation (BEC) in ultra-cold atomic gases and the observation a new type of quantum fluid with specific characteristics derived from its intrinsic out-of-equilibrium nature. The main objective of this book is to take a snapshot of the state-of-the-art of this fast moving field with a special emphasis on the hot topics and new trends. Bringing together the most active specialists of the two areas (atomic and polaritonic quantum fluids), we expect that this book will facilitate the exchange and the collaboration between these two communities working on subjects with very strong analogies.

This is a comprehensive textbook designed for graduate and advanced undergraduate students. Both authors rely on more than 20 years of teaching experience in renowned Physics Engineering courses to write this book addressing the students' needs. Kinetics and Spectroscopy of Low Temperature Plasmas derives in a full self-consistent way the electron kinetic theory used to describe low temperature plasmas created in the laboratory with an electrical discharge, and presents the main optical spectroscopic diagnostics used to characterize such plasmas. The chapters with the theoretical contents make use of a deductive approach in which the electron kinetic theory applied to plasmas with basis on the electron Boltzmann equation is derived from the basic concepts of Statistical and Plasma Physics. On the other hand, the main optical spectroscopy diagnostics used to characterize experimentally such plasmas are presented and justified from the point of view of the Atomic and Molecular Physics. Low temperature plasmas (LTP) are partially ionized gases with a broad use in many technological applications such as microelectronics, light sources, lasers, biology and medicine. LTPs lead to the production of atomic and molecular excited states, chemically reactive radicals, and activated surface sites, which are in the origin, among others, of the deposition of thin films, advanced nanotechnology products, solar cells, highly efficient combustion motors, and treatment of cancer cells.

This thesis describes how to create and probe novel phases of matter and exotic (non-quasiparticle) behavior in cold atomic gases. It focuses on situations whose physics is relevant to condensed matter systems, and where open questions about these latter systems can be addressed. It also attempts to better understand several experimental anomalies in condensed matter systems.

The thesis is divided into five parts. The first section or chapter of each part gives an introduction to the motivation and background for the physics of that part; the last section or chapter gives an outlook for future studies. Parts 1-4 introduce and show different facets of how to learn about novel physics relevant to condensed matter using cold atomic systems. Part 5 constrains explanations of several ill-understood phenomena occurring in low-temperature quantum solids and condensed matter systems and attempts to construct mechanisms for their behavior.

Cold atomic gases trapped and manipulated on atom chips allow the realization of seminal one-dimensional (1d) quantum many-body problems in an isolated and well controlled environment. In this context, this thesis presents an extensive experimental study of non-equilibrium dynamics in 1d Bose gases, with a focus on processes that go beyond simple dephasing dynamics. It reports on the observation of recurrences of coherence in the post-quench dynamics of a pair of 1d Bose gases and presents a detailed study of their decay. The latter represents the first observation of phonon-phonon scattering in these systems. Furthermore, the thesis investigates a novel cooling mechanism occurring in Bose gases subjected to a uniform loss of particles. Together, the results presented show a wide range of non-equilibrium phenomena occurring in 1d Bose gases and establish them as an ideal testbed for many-body physics beyond equilibrium.

This book provides an attempt to convey the colorful facets of condensed matter systems with reduced dimensionality. Some of the specific features predicted for interacting one-dimensional electron systems, such as charge- and spin-density waves, have been observed in many quasi-one-dimensional materials. The two-dimensional world is even richer: besides d-wave superconductivity and the Quantum Hall Effect - perhaps the most spectacular phases explored during the last two decades - many collective charge and spin states have captured the interest of researchers, such as charge stripes or spontaneously generated circulating currents.

Recent years have witnessed important progress in material preparation, measurement techniques and theoretical methods. Today larger and better samples, higher flux for neutron beams, advanced light sources, better resolution in electron spectroscopy, new computational algorithms, and the development of field-theoretical approaches allow an in-depth analysis of the complex many-body behaviour of low-dimensional materials. The epoch when simple mean-field arguments were sufficient for describing the gross features observed experimentally is definitely over.

The Editors' aim is to thoroughly explain a number of selected topics: the application of dynamical probes, such as neutron scattering, optical absorption and photoemission, as well as transport studies, both electrical and thermal. Some of the more theoretical chapters are directly relevant for experiments, such as optical spectroscopy, transport in one-dimensional models, and the phenomenology of charge inhomogeneities in layered materials, while others discuss more general topics and methods, for example the concept of a Luttinger liquid and bosonization, or duality transformations, both promising tools for treating strongly interacting many-body systems.

A number of interrelated areas of low temperature physics are brought together in this volume. The four topics are presented as separate chapters. First is the study of the Kibble-Zurek mechanism for defect formation following quench cooling of superfluid 3He and its relation to quantum field theory. Properties of heavy fermion materials are described next with special attention to the competition between magnetism and superconductivity. Some of the newest correlated electron systems are discussed and the arguments for possible unconventional nature of the superconducting order parameter are presented for these systems, including the novel coexistence of ferromagnetism and superconductivity. Highly polarized degenerate Fermi liquids are of substantial interest in many areas of physics. The most complete description of observations of thermodynamic and transport phenomena are reviewed here for the case of polarized liquid 3He obtained by rapid melting from a polarized solid and subsequent rapid refrigeration. Properties of the melting curve of 3He, and the related technique of melting curve thermometry are described in detail.
- Superfluid 3He and Quantum Field Theory
- Large Scale structure of the Universe
- Unconventional Superconductivity
- Heavy Fermions
- Quantum Phase Transitions
- Polarized Fermi Liquids
- Rapid Melting
- 3He Melting Curve
- Low Temperature Thermometry