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.

The problem of conventional, low-temperature superconductivity has been regarded as solved since the seminal work of Bardeen, Cooper, and Schrieffer (BCS) more than 50 years ago. However, the theory does not allow accurate predictions of some of the most fundamental properties of a superconductor, including the superconducting energy gap on the Fermi surface. This thesis describes the development and scientific implementation of a new experimental method that puts this old problem into an entirely new light. The nominee has made major contributions to the development and implementation of a new experimental method that enhances the resolution of spectroscopic experiments on dispersive lattice-vibrational excitations (the "glue" responsible for Cooper pairing of electrons in conventional superconductors) by more than two orders of magnitude. Using this method,he has discovered an unexpected relationship between the superconducting energy gap and the geometry of the Fermi surface in the normal state, both of which leave subtle imprints in the lattice vibrations that could not be resolved by conventional spectroscopic methods. He has confirmed this relationship on two elemental superconductors and on a series of metallic alloys. This indicates that a mechanism qualitatively beyond the standard BCS theory determines the magnitude and anisotropy of the superconducting gap.

The Sixth International Cryogenic Materials Conference (ICMC) was held on the campus of Massachusetts Institute of Technology in Cambridge in col laboration with the Cryogenic Engineering Conference (CEC) on August 12-16, 1985. The complementary program and the interdependence of these two dis ciplines foster the conference. Its manifest purpose is sharing the latest advances in low temperature materials science and technology. Equally im portant, areas of needed research are identified, prioriti-es for new research are set, and an increased appreciation of interdisciplinary, interlaboratory, and international cooperation ensues. The success of the conference is the result of the. able leadership and hard work of many people: S. Foner of M.I.T. coordinated ICMC efforts as its Conference Chairman. A. I. Braginski of Westinghouse R&D Center planned the program with the assistance of Cochairmen E. N. C. Dalder of Lawrence Livermore National Laboratory, T. P. Orlando of M.I.T., D. O. Welch of Brookhaven National Laboratory, and numerous other committee members. A. M. Dawson of M.I.T., Chairman of Local Arrangements, and G. M. Fitzgerald, Chairman of Special Events, skillfully managed the joint conference. The contributions of the CEC Board, and particularly its conference chairman, J. L. Smith, Jr. of M.I.T., to the organization of the joint conference are also gratefully acknm.ledged.

Ultra-cold atomic ensembles have emerged in recent years as a powerful tool in many-body physics research, quantum information science and metrology. This thesis presents an experimental and theoretical study of the coherent properties of trapped atomic ensembles at high densities, which are essential to many of the aforementioned applications. The study focuses on how inter-particle interactions modify the ensemble coherence dynamics, and whether it is possible to extend the coherence time by means of external control. The thesis presents a theoretical model which explains the effect of elastic collision of the coherence dynamics and then reports on experiments which test this model successfully in the lab. Furthermore, the work includes the first implementation of dynamical decoupling with ultra-cold atomic ensembles. It is demonstrated experimentally that by using dynamical decoupling the coherence time can be extended 20-fold. This has a great potential to increase the usefulness of these ensembles for quantum computation.

High-Temperature Cuprate Superconductors provides an up-to-date and comprehensive review of the properties of these fascinating materials. The essential properties of high-temperature cuprate superconductors are reviewed on the background of their theoretical interpretation. The experimental results for structural, magnetic, thermal, electric, optical and lattice properties of various cuprate superconductors are presented with respect to relevant theoretical models. A critical comparison of various theoretical models involving strong electron correlations, antiferromagnetic spin fluctuations, phonons and excitons provides a background for understanding of the mechanism of high-temperature superconductivity. Recent achievements in their applications are also reviewed. A large number of illustrations and tables gives valuable information for specialists. A text-book level presentation with formulation of a general theory of strong-coupling superconductivity will help students and researches to consolidate their knowledge of this remarkable class of materials.

Modern techniques from quantum field theory are applied in this work to the description of ultracold quantum gases. This leads to a unified description of many phenomena including superfluidity for bosons and fermions, classical and quantum phase transitions, different dimensions, thermodynamic properties and few-body phenomena as bound state formation or the Efimov effect. The non-perturbative treatment with renormalization group flow equations can account for all known limiting cases by solving one single equation. It improves previous results quantitatively and brings qualitatively new insights. As an example, new quantum phase transitions are found for fermions with three spin states. Ultracold atomic gases can be seen as an interesting model for features of high energy physics and for condensed matter theory. The research reported in this thesis helps to solve the difficult complexity problem in modern theoretical physics.

This book presents the anisotropy and multiband effects in newly discovered unconventional superconductors: cuprate superconductors, borocarbides, magnezium-diboride and oxypnictides. The physical properties of these unconventional superconductors and the application of the two-band Ginzburg-Landau theory to these superconducting compounds are explained. Temperature dependencies of fundamental superconducting parameters are calculated using the GL theory taking into account multiband-and anisotropy effects. A comparision of theoretical results and experimental data is conducted. Additionally, the analytical solution of the microscopical Eliashberg theory and of the BCS theory is developed for two-band and anisotropic superconductors. Fluctuation effects in newly discovered superconductors are also discussed.

This book is intended to provide a clear and unified introduction to the physics of matter at low temperatures, and to do so at a level accessible to researchers new to the field and to graduate and senior undergraduate students. Rapid scientific progress made over the last seven years in a number of specific areas-for example, high-Tc superconductivity and the quantum Hall effect-has inevitably rendered our earlier Matter at Low Temperatures somewhat out of date. We have therefore taken the opportunity to revise and amend the text in its entirety and, at the same time, to furnish it with what we believe to be a more apt title, emphasizing that it is with the physics of low temperatures that we are particularly concerned. Like its predecessor, Low-Temperature Physics is devoted to the fascinating and diverse phenomena that occur under conditions of extreme cold, many of which have no analogue at all in the everyday world at room temperature.

Stuart Wolf This book originated as a series of lectures that were given as part of a Summer School on Spintronics in the end of August, 1998 at Lake Tahoe, Nevada. It has taken some time to get these lectures in a form suitable for this book and so the process has been an iterative one to provide current information on the topics that are covered. There are some topics that have developed in the intervening years and we have tried to at least alert the readers to them in the Introduction where a rather complete set of references is provided to the current state of the art. The field of magnetism, once thought to be dead or dying, has seen a remarkable rebirth in the last decade and promises to get even more important as we enter the new millennium. This rebirth is due to some very new insight into how the spin degree of freedom of both electrons and nucleons can play a role in a new type of electronics that utilizes the spin in addition to or in place of the charge. For this new field to mature and prosper, it is important that students and postdoctoral fellows have access to the appropriate literature that can give them a sound basis in the funda mentals of this new field and I hope that this book is a very good start in this direction.

71 For a given value of I the field is independent of the geometrical composition of the coil inside the winding space. The actual number of turns and the cross section of the conductors is entirely determined by the impedance of the power supply to which the magnet should be adapted. In the case of low impedance (high current and low voltage) few turns of thick metal should be used. In the case of high impedance (low current and high voltage) many turns of thin material are needed. High impedance coils are made of square wire or flat strip wound into layers or "pancakes" 1. A nice system for low impedance coils was deve loped by BITTER. The turns of his magnets consist of flat copper discs separated by thin insulating sheets and joined together at their edges. In this type of coil the current density is higher near the axis than at the exterior, resulting into a higher value for G (see above). For the details of the construction we refer to the original papers 2, 3. If the power is dissipated at a low voltage the cooling may be achieved with the help of water. Distilled water should be preferred over mains' water in order to prevent the magnet from corrosion. In the case of a high voltage coil some non-inflammable organic fluid should be used. A low viscosity and a large specific heat are advantageous."

This Volume 5 in a continuing series represents the compilation of papers presented at the International Symposium on Analytical Calorimetry as part of the 185th National Meeting of the American Chemical Society, Seattle, Washington, March 20-25th. 1983. A much broader variety of topics are covered than in pre vious volumes, due to the growth in the field of Thermal Analysis. Specific topics covering such techniques as differential scanning calorimetry, combined thermogravimetric procedures, dynamic mechan ical analysis and a variety of novel kinetic analyses are covered. A wide range of material types are included in this volume such as polymers (alloys, blends and composites), fossil fuels, biological products, liquid crystals and inorganic materials. The co-editors of this volume would like to thank all the contributors for their efforts in conforming to the manuscript requirements, and for being prompt in the preparation. We would also like to thank those who presided over sessions during the course of the symposium; Professor Anselm C. Griffin, Professor Roger S. Porter and Dr. Edith A. Turi."

Cold and ultracold collisions occupy a strategic position at the intersection of several powerful themes of current research in chemical physics, in atomic, molecular and optical physics, and even in condensed matter. The nature of these collisions has important consequences for optical manipulation of inelastic and reactive processes, precision measurement of molecular and atomic properties, matter-wave coherences and quantum-statistical condensates of dilute, weakly interacting atoms. This crucial position explains the wide interest and explosive growth of the field since its inception in 1987. The author reviews elements of the quantum theory of scattering theory, collisions taking place in the presence of one or more light fields, and collisions in the dark, below the photon recoil limit imposed by the presence of any light field. Finally, it reviews the essential properties of these mesoscopic quantum systems and describes the key importance of the scattering length to condensate stability.

Recent experimental and theoretical progress has elucidated the tunable crossover, in ultracold Fermi gases, from BCS-type superconductors to BEC-type superfluids.

"The BCS-BEC Crossover and the Unitary Fermi Gas" is a collaborative effort by leading international experts to provide an up-to-date introduction and a comprehensive overview of current research in this fast-moving field.

It is now understood that the unitary regime that lies right in the middle of the crossover has remarkable universal properties, arising from scale invariance, and has connections with fields as diverse as nuclear physics and string theory.

This volume will serve as a first point of reference for active researchers in the field, and will benefit the many non-specialists and graduate students who require a self-contained, approachable exposition of the subject matter.

"

Electrons and ions have been used for over 40 years as probes to investigate the fascinating properties of helium liquids. The study of the transport properties of microscopic charge carriers sheds light on superfluidity, on quantum hydrodynamics, and on the interactions with collective excitations in quantum liquids. The structure of the probes themselves depends on their coupling with the liquid environment in a way that gives further insight into the microscopic behavior of the liquid in different thermodynamic conditions, such as in the superfluid phase, in the normal phase, or near the liquid-vapor critical point. This book provides a comprehensive review of the experiments and theories of transport properties of charge carriers in liquid helium. It is a subject about which no other monograph exists to date. The book is intended for graduate and postgraduate students and for condensed matter physicists who will benefit from its completeness and accuracy.

New Trends in Superconductivity contains up-to-date papers covering the most exciting current topics in superconductivity research. The main areas include cuprate superconductivity, covering mechanisms, pairing symmetry, pseudogap, stripes, growth and synthesis; novel superconductors, including MgB2, Sr2RuO4, borocarbides and C60-based systems; and mesoscopic superconductors and vortex matter, including vortex structure, type II superconductors, macroscopic quantum coherence and qubit devices and multilayer systems.

A useful, up-to-date reference of current research in all of these rapidly developing fields of superconductivity.

A broad introduction to high Tc superconductors, their parent compounds and related novel materials, covering both fundamental questions of modern solid state physics (such as correlation effects, fluctuations, unconventional symmetry of superconducting order parameter) and applied problems related to short coherence length, grain boundaries and thin films. The information that can be derived from electron spectroscopy and optical measurements is illustrated and explained in detail. Descriptions widely employ the clear, relatively simple, phenomenological Ginzburg-Landau model of complex phenomena, such as vortex physics, vortex charge determination, plasmons in superconductors, Cooper pair mass, and wetting of surfaces. The first comprehensive reviews of several novel classes of materials are presented, including borocarbides and chain cuprates.

A summary of recent developments in theoretical and experimental studies of fluctuation effects in itinerant electron magnets, focusing on novel physical phenomena: soft-mode spin fluctuations and zero-point effects, strong spin anharmonicity, magnetic frustrations in metals, fluctuation effects in Invar alloys and low-dimensional systems. All of these may be important for novel high-technology applications.

The work described in this book originates from a major effort to develop a fundamental theory of the glass and the jamming transitions. The first chapters guide the reader through the phenomenology of supercooled liquids and structural glasses and provide the tools to analyze the most frequently used models able to predict the complex behavior of such systems. A fundamental outcome is a detailed theoretical derivation of an effective thermodynamic potential, along with the study of anomalous vibrational properties of sphere systems. The interested reader can find in these pages a clear and deep analysis of mean-field models as well as the description of advanced beyond-mean-field perturbative expansions. To investigate important second-order phase transitions in lattice models, the last part of the book proposes an innovative theoretical approach, based on a multi-layer construction. The different methods developed in this thesis shed new light on important connections among constraint satisfaction problems, jamming and critical phenomena in complex systems, and lay part of the groundwork for a complete theory of amorphous solids.

Starting from first principles, this book introduces the closely related phenomena of Bose condensation and Cooper pairing, in which a very large number of single particles or pairs of particles are forced to behave in exactly the same way, and explores their consequences in condensed matter systems. Eschewing advanced formal methods, the author uses simple concepts and arguments to account for the various qualitatively new phenomena which occur in Bose-condensed and Cooper-paired systems, including but not limited to the spectacular macroscopic phenomena of superconductivity and superfluidity. The physical systems discussed include liquid 4-He, the BEC alkali gases, 'classical' superconductors, superfluid 3-He, 'exotic' superconductors and the recently stabilized Fermi alkali gases. The book should be accessible to beginning graduate students in physics or advanced undergraduates.

In recent years, there has been much synergy between the exciting areas of quantum information science and ultracold atoms. This volume, as part of the proceedings for the XCI session of Les Houches School of Physics (held for the first time outside Europe in Singapore) brings together experts in both fields. The theme of the school focused on two principal topics: quantum information science and ultracold atomic physics. The topics range from Bose Einstein Condensates to Degenerate Fermi Gases to fundamental concepts in Quantum Information Sciences, including some special topics on Quantum Hall Effects, Quantum Phase Transition, Interactions in Quantum Fluids, Disorder and Interference Phenomenoma, Trapped Ions and Atoms, and Quantum Optical Devices.

For hundreds of years, models of magnetism have been pivotal in the understanding and advancement of science and technology, from the Earth's interpretation as a magnetic dipole to quantum mechanics, statistical physics, and modern nanotechnology. This book is the first to envision the field of magnetism in its entirety. It complements a rich literature on specific models of magnetism and provides an introduction to simple models, including some simple limits of complicated models. The book is written in an easily accessible style, with a limited amount of mathematics, and covers a wide range of quantum-mechanical, finite-temperature, micromagnetic and dynamical models. It deals not only with basic magnetic quantities, such as moment, Curie temperature, anisotropy, and coercivity, but also with modern areas such as nanomagnetism and spintronics, and with 'exotic' themes, as exemplified by the polymer analogy of magnetic phase transitions. Throughout the book, a sharp line is drawn between simple and simplistic models, and much space is devoted to discuss the merits and failures of the individual model approaches.

Most previous texts on quantum optics have been written primarily for the graduate student market at PhD level and above. Quantum optics: an introduction aims to introduce a wide range of topics at a lower level suitable for advanced undergraduate and masters level students in physics. The
text is divided into four main parts, covering modern topics in both pure and applied quantum optics: I Introduction and background material. II. Photons. III. Atom-photon interactions. IV. Quantum information processing. The emphasis of the subject development is on intuitive physical
understanding rather than mathematical arguments, although many derivations are included where appropriate. The text includes numerous illustrations, with a particular emphasis on the experimental observations of quantum optical phenomena. Each chapter includes worked examples, together with 10-15
exercises with solutions. Six appendices are included to supplement the main subject material.

Like for its three predecessors, the purpose of this fourth edition is chiefly to help physicists, physical chemists, materials scientists, metallurgists, engineers, and biologists to carry out investigations at low temperatures. This new edition takes into account the major changes in cryogenic technology over the past twenty years. These changes include areas of temperature measurement and control, superconducting magnets, cryocoolers, ultra-low temperatures, technical data on materials, commercially available cryostats for optical, x-ray, thermal and electrical measurements. Less emphasis is now placed on methods of constructing cryostats in the laboratory and more emphasis on commercially available cryostats, temperature controllers, and closed circuit cryocoolers. The book contains comprehensive, up-to-date tables of physical property data on metals, polymers, and ceramics. It will be of value to graduate students as well as to engineers and biologists facing cryogenic problems.

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.