Nanoscale Science and Technology summarizes six years of active research sponsored by NATO with the participation of the leading experts. The book provides an interdisciplinary view of several aspects of physics at the atomic scale. It contains an overview of the latest findings on the transport of electrons in nanowires and nanoconstrictions, the role of forces in probe microscopy, the control of structures and properties in the nanometer range, aspects of magnetization in nanometric structures, and local probes for nondestructive measurement as provided by light and metal clusters near atomic scales.

Deng Feng Wang was born February 8, 1965 in Chongqing City, China and died August 15, 1999 while swimming with friends in the Atlantic Ocean off Island Beach State Park, New Jersey. In his brief life, he was to have an influence far beyond his years. On August 12th 2000, The Deng Feng Wang Memorial Conference was held at his alma mater, Princeton University, during which Deng Feng's mentors, collaborators and friends presented scientific talks in a testimonial to his tremendous influence on their work and careers. The first part of this volume contains proceedings contributions from the conference, with plenary talks by Nobel Laureate Professor Phil Anderson of Princeton University and leading Condensed Matter Theorists Professor Piers Coleman of Rutgers University and Professor Christian Gruber of the University of Lausanne. Other talks, given by collaborators, friends and classmates testify to the great breadth of Deng Feng Wang's influence, with remarkable connections shown between seemingly unrelated areas in physics such as Condensed Matter Physics, Superconductivity, One-Dimensional Models, Statistical Physics, Mathematical Physics, Quantum Field Theory, High Energy Theory, Nuclear Magnetic Resonance, Supersymmetry, M-Theory and String Theory, in addition to such varied fields outside of physics such as Oil Drilling, Mixed Signal Circuits and Neurology. The second part of the volume consists of reprints of some of Deng Feng Wang's most important papers in the areas of Condensed Matter Physics, Statistical Physics, Magnetism, Mathematical Physics and Mathematical Finance. This volume represents a fascinating synthesis of a wide variety of topics, and ultimately points to the universality of physics and of science as a whole. As such, it represents a fitting tribute to a remarkable individual, whose tragic death will never erase his enduring influence.

I am very pleased that my book The Geomagnetic Field and Life is being published in English in the United States. Thanks to the initiative of Plenum Press, a publishing hause that is widely known in all countries, I have a great new opportunity to make direct contact with friends throughout the world. My book on the geomagnetic field can be regarded as an abstraction, whose purpose is to provide a better picture and understanding of the world araund us, its main driving forces, and factors, to help us to know ourselves, and to proceed further. The essence of the abstraction is that in treating the problern I have deliberately ignored the diverse effects of various extemal factors on living organisms and have confined myself to an analysis of the effect of the GMF. This approach allows me to go one step further-to draw various conclusions and propose theories that rnight bring us closer to a proper understanding of the true nature of the phenomena. Philosophers have long been aware that by such abstract thinking we can deterrnine the nature of phenomena more reliably, completely, and comprehensively, penetrate to the very core of the observed effects, and perceive the depth of their interrelations.

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.

During the last twenty years the lifestyle of a large portion of the inhabitants of our planet has changed dramatically. This would never have been possible without the massive use of electronic and photonic technology, telecommuni cations, and computers. These disciplines are designed to code, transmit, detect, decode, and process signals and related information, and can be broadly addressed as information science and technology. In the sophisticated society in which we live and operate, this science is diffused transversely and plays a major role in almost every human activity. Information science and technology is the basis of a powerful industry that does not suffer the shortcomings of more traditional human enterprises. Information is a renewable source and its control and processing rely on software codes, which are a creation of the mind, and on related hardware, incredibly sophisticated but made out of simple, abundant materials. The rate of change and transformation of this industry is the highest mankind has ever experienced, and it requires not only the replacement of technologies but also a continuous updating of expertise to keep up with the rapid transformation. There is no doubt that this calls for a change in university training, to avoid students graduating at an already obsolete level.

The magnetism of iron and other transition metals had been a subject of inten sive research for a long time, but the understanding of the microscopic origin of "metallic magnetism" was quite limited until the early 1970's. During the last 10 to 15 years both theory and experiment contributed towards signif icant progress in this field, such that today a qualitative understanding has been achieved. The word "qualitative" indicates that the knowledge is still not complete; although many properties, the ground state as well as the finite temperature behaviour and the phase transition from magnetic order at low temperatures to the paramagnetic state at high temperatures, can be explained in a coherent way, a quantitative description still is not fully achieved. It is certainly appropriate to summarize the developments of the last 15 years and the present-day understanding of the field, this is the aim of this Topics volume. The form chosen is a collection of reviews, written by prominent scientists who themselves contributed decisively to the progress. Scientists with a general interest in the field as well as specialists and active researchers in metallic magnetism should be able to profit from the two-volume treatment. The subjects not covered extensively in the present first volume (in particular neutron scattering and electronic structure properties) will make up the second volume."

In this book, the fundamentals of magnetism are treated, starting at an introductory level. The origin of magnetic moments, the response to an applied magnetic field, and the various interactions giving rise to different types of magnetic ordering in solids are presented and many examples are given. Crystalline-electric-field effects are treated at a level that is sufficient to provide the basic knowledge necessary in understanding the properties of materials in which these effects play a role. Itinerant-electron magnetism is presented on a similar basis. Particular attention has been given to magnetocrystalline magnetic anisotropy and the magnetocaloric effect. Also, the usual techniques for magnetic measurements are presented. About half of the book is devoted to magnetic materials and the properties that make them suitable for numerous applications. The state of the art is presented of permanent magnets, high-density recording materials, soft-magnetic materials, Invar alloys and magnetostrictive materials. Many references are given.

In the past two decades a succession of direct observations by satellites, and of extensive computer simulations, has led to the realization that the polar ionosphere plays a principal role in large-scale magnetospheric processes - a manifestation of the physics linkage involved in solar-terrestrial interactions. Spatial/temporal variations in high-latitude electromagnetic phenomena, such as dynamic aurorae, electric fields and currents, have proved to be extremely complex. Now the challenge is to comprehend the vast amount of complicated measurements made in this magnetosphere-ionosphere sysstem of the Earth. This book addresses the electrical coupling between the hot, but dilute, magnetospheric plasma and the cold, but dense, plasma in the ionosphere. In five major chapters, this book presents: - basic properties of magnetosphere-ionosphere coupling; - morphology of electric fields and currents at high latitudes; - global modeling of magnetosphere-ionosphere coupling; - modeling of ionospheric electrodynamics; - current issues, such as auroral particle acceleration, substorms, penetration of high-latitude fields into low latitudes.

Advances in the synthesis of new materials with often complex, nano-scaled structures require increasingly sophisticated experimental techniques that can probe the electronic states, the atomic magnetic moments and the magnetic microstructures responsible for the properties of these materials. At the same time, progress in synchrotron radiation techniques has ensured that these light sources remain a key tool of investigation, e.g. synchrotron radiation sources of the third generation are able to support magnetic imaging on a sub-micrometer scale. With the Fifth Mittelwihr School on Magnetism and Synchrotron Radiation the tradition of teaching the state-of-the-art on modern research developments continues and is expressed through the present set of extensive lectures provided in this volume. While primarily aimed at postgraduate students and newcomers to the field, this volume will also benefit researchers and lecturers actively working in the field.

When I started in magnetic recording nearly fifty years ago, it was easy to perceive the common sense of it. There was very little mathematics and every new finding was a source of wonder. I have tried to recapture this spirit with simple explanations, while maintaining a high density of infonnation and cov- ering the entire field. This book introduces a novice to magnetic recording and its many branches. It includes reference data for designers and users. Each chapter stands by itself; no prerequisites are essential. For a quick survey, the equations and worked- out examples can be disregarded. The magnetic recording art is changing so rapidly that new advances are announced almost every month. These are properly covered by journal articles and manufacturers' catalogs. This book will fulfil its purpose if it gives a back- ground for easily comprehending the new advances. I have included subjects and devices not found elsewhere, and some unconventional viewpoints. I would welcome comments from readers. To Jay McKnight I am deeply grateful for important suggestions and helpful comments. I appreciate also the help of BASF, John Boyers, Joseph Dundovic, Charles Ginsburg, Peter Hammar, Yasuo Imaoka, Hal Kaitchuk, Otto Kornei, Harold Miller, Jack Mullin, Jim Novak, Lenard Perlman, Carl Powell, Sidney Rubens, John Shennan, Shigeo Shima, Heinz Thiele, Yoshimi Watanabe and many others; and to my daughter Ruth for typing.

The field of highly frustrated magnetism has developed considerably and expanded over the last 15 years. Issuing from canonical geometric frustration of interactions, it now extends over other aspects with many degrees of freedom such as magneto-elastic couplings, orbital degrees of freedom, dilution effects, and electron doping. Its is thus shown here that the concept of frustration impacts on many other fields in physics than magnetism. This book represents a state-of-the-art review aimed at a broad audience with tutorial chapters and more topical ones, encompassing solid-state chemistry, experimental and theoretical physics.

Diluted magnetic semiconductors, or semimagnetic semiconductors, seemed for a while to be one of those research topics whose glory (i. e. , the period of most ext- sive research) belongedalready to the past. This particularlyapplied to "traditional" diluted magnetic semiconductors, i. e. , substitutional alloys of either II-VI or IV-VI semiconductors with transition metal ions. Fortunately, a discovery, in the beg- ning of the nineties [1,2], of ferromagnetic ordering in III-V DMSs with critical temperatures reaching 170 K has renewed and greatly intensi ed an interest in those materials. This was, at least partially, related to expectations that their Curie temperatures can be relatively easily brought to room temperature range through a clearly delineatedpath and,partially,due to the great successes, also commercial,of metallic version of spintronics, which earned its founders the Nobel Prize in 2007. The semiconductor version of spintronics has attracted researchers also because of hopes to engage it in efforts to construct quantum information processing devices. While these hopes and expectations are not fully realized yet, the effort is going on. As a goodexampleof recentachievements,new resultson quantumdotsconta- ing a single magnetic ion should be mentioned. A great progress has been achieved in studies of excitonic states in such quantum dots, so far limited to InAs/GaAs [3,4] and CdTe/ZnTe [5,6] material systems and to Manganese as the magnetic ion. Furthermore, in the II-VI QDs, rst results on the optical control of the Mn spin states havebeenexperimentallydemonstrated[7-9]andtheoreticallyanalyzed[10]; the studies of Mn spin dynamics and control in III-V QDs will certainly follow.

The general theory of magnetism and the vast range of individual phe nomena it embraces have already been examined in many volumes. Spe cialists hardly need help in charting their way through the maze of pub lished information. At the same time, a nonspecialist might easily be discouraged by this abundance. Most texts are restricted in their coverage, and their concepts may well appear to be disorganized when the uninitiated attempt to consider them in their totality. Since the subject is already thoroughly researched with very little new information added year by year, this is hardly a satisfactory state of affairs. By now, it should be possible for anyone with even a minimum of technical competence to feel com pletely at home with all of the basic magnetic principles. The present volume addresses this issue by stressing simplicity-sim plicity of order and simplicity of range as well as simplicity of detail. It proposes a pattern of logical classification based on the electronic con sequences that result whenever any form of matter interacts with any kind of energy. An attempt has been made to present each phenomenon of interest in its most visually graphic form while reducing the verbal de scription to the minimum needed to back up the illustrations. This might be called a Life magazine type of approach, in which each point is prin cipally supported by a picture. The illustrations make use of two (perhaps unique) conventions."

1. Lyotropic Liquid Crystals The class of compounds known as thermotropic liquid crystals has been widely utilized in basic research and industry during recent years. The properties of these materials are such that on heating from the solid to the isotropic liquid state, phase transitions occur with the formation of one or more intermediate anisotropic liquids. The unique and sometimes startling properties of these liquid crystals are the properties of pure compounds. However, there exists a second class of substances known as lyotropic liquid crystals which obtain their anisotropic properties from the mixing of two or more components. One of the components is amphiphilic, containing a polar head group (generally ionic or zwitterionic) attached to one or more long-chain hydrocarbons; the second component is usually water. Lyotropic liquid crystals occur abundantly in nature, particularly in all living systems. As a consequence, a bright future seems assured for studies on such systems. Even now, many of the properties of these systems are poorly understood. It is the purpose of this review to consolidate the results obtained from nuclear magnetic resonance studies of such systems and to provide a coherent picture of the field. Probably the most familiar example of a lyotropic liquid crystal is soap in water. A common soap is sodium dodecylsulphate where an ionic group (sulphate) is attached to a hydrocarbon chain containing twelve carbons.

This textbook sets out to enable readers to understand fundamental aspects underlying quantum macroscopic phenomena in solids, primarily through the modern experimental techniques and results. The classic independent-electrons approach for describing the electronic structure in terms of energy bands helps explain the occurrence of metals, insulators and semiconductors.It is underlined thatsuperconductivity and magnetism can only be understood by taking into account the interactions between electrons. The text recounts the experimental observations that have revealed the main properties of the superconductors and were essential to track its physical origin. While fundamental concepts are underlined, those which are required to describe the high technology applications, present or future, are emphasized as well. Problem sets involve experimental approaches and tools which support a practical understanding of the materials and their behaviour.

Solid state magnetism is important and attempts to understand magnetic properties have led to an increasingly deep insight into the fundamental make up of solids. Both experimental and theoretical research into magnetism continue to be very active, yet there is still much ground to cover before there can be a full understanding. There is a strong interplay between the developments of materials science and of magnetism. Hundreds of new materials have been dis covered, often with previously unobserved and puzzling magnetic prop erties. A large and growing technology exists that is based on the magnetic properties of materials. Very many devices used in everyday life involve magnetism and new applications are being invented all the time. Under standing the fundamental background to the applications is vital to using and developing them. The aim of this book is to provide a simple, up-to-date introduction to the study of solid state magnetism, both intrinsic and technical. It is designed to meet the needs and interests of advanced undergraduate students reading physics; of postgraduates in physical and materials sciences and in engineering; and also those of the practising scientist specializing in another area who requires an introduction to magnetism."

Magnetohydrodynamics, or MHD, is a theoretical way of describing the statics and dynamics of electrically conducting uids. The most important of these uids occurring in both nature and the laboratory are ionized gases, called plasmas. These have the simultaneous properties of conducting electricity and being electrically charge neutral on almost all length scales. The study of these gases is called plasma physics. MHD is the poor cousin of plasma physics. It is the simplest theory of plasma dynamics. In most introductory courses, it is usually afforded a short chapter or lecture at most: Alfven waves, the kink mode, and that is it. (Now, on to Landau damping ) In advanced plasma courses, such as those dealing with waves or kinetic theory, it is given an even more cursory treatment, a brief mention on the way to things more profound and interesting. (It is just MHD Besides, real plasma phy- cists do kinetic theory ) Nonetheless, MHD is an indispensable tool in all applications of plasma physics."

Monte Carlo computer simulations are now a standard tool in scientific fields such as condensed-matter physics, including surface-physics and applied-physics problems (metallurgy, diffusion, and segregation, etc. ), chemical physics, including studies of solutions, chemical reactions, polymer statistics, etc., and field theory. With the increasing ability of this method to deal with quantum-mechanical problems such as quantum spin systems or many-fermion problems, it will become useful for other questions in the fields of elementary-particle and nuclear physics as well. The large number of recent publications dealing either with applications or further development of some aspects of this method is a clear indication that the scientific community has realized the power and versatility of Monte Carlo simula tions, as well as of related simulation techniques such as "molecular dynamics" and "Langevin dynamics," which are only briefly mentioned in the present book. With the increasing availability of recent very-high-speed general-purpose computers, many problems become tractable which have so far escaped satisfactory treatment due to prac tical limitations (too small systems had to be chosen, or too short averaging times had to be used). While this approach is admittedly rather expensive, two cheaper alternatives have become available, too: (i) array or vector processors specifical ly suited for wide classes of simulation purposes; (ii) special purpose processors, which are built for a more specific class of problems or, in the extreme case, for the simulation of one single model system."

Physics of New Materials After the discoveries and applications of superconductors, new ceramics, amorphous and nano-materials, shape memory and other intelligent materials, physics became more and more important, comparable with chemistry, in the research and development of advanced materials. In this book, several important fields of physics-oriented new-materials research and physical means of analyses are selected and their fundamental principles and methods are described in a simple and understandable way. It is suitable as a textbook for university materials science courses.

The ?eld of Nanomagnetism is a young branch of the study of magnetic phenomena, phenomena that have been a source of amazement and stimulus for speculation for more than 3,000 years [1]. Nanomagnetism, despite being a young area, has already affected every sphere of human activity, through its fundamental contribution to make the computer an ubiquitous instrument for communication, control of industrial processes, medical diagnosis, scienti?c investigation, or leisure. The studies of particulate and thin ?lm magnetic media and other related questions led to improvements that have mul- plied, in ?ve decades, the amount of data that can be encoded into a unitary area by some 50 million times. The 2007 Nobel Prize in Physics, awarded to Albert Fert and Peter Grunberg, is an important recognition of the extraordinary achievements of the research in Na- magnetism. The unfolding revolution brought about by Spintronics is intimately c- nected, and enhances the relevance of these developments. Nanomagnetism already encompasses a very wide range of remarkable pr- erties and phenomena, as illustrated in the case of thin ?lms, for example, by the volumes of the series on Ultrathin Magnetic Structures [2].

Polarization involves the vectorial nature of light fields. In current applications of optical science, the electromagnetic description of light with its vector features has been shown to be essential: In practice, optical radiation also exhibits randomness and spatial non-uniformity of the polarization state. Moreover, propagation through photonic devices can alter the correlation properties of the light field, resulting in changes in polarization. All these vectorial properties have been gaining importance in recent years, and they are attracting increasing attention in the literature. This is the framework and the scope of the present book, which includes the authors' own contributions to these issues.

The Cargese Summer Institute 1975 on Weak and EZeotromagnetio Interaotions at High Energies was organized by the Universite Pierre et Marie Curie (M. LEVY et J. L. BASDEVANT)~ the KathoZieke Universiteit te Leuven (R. GASTMANS) and the Universite CathoZique de Louvain (D. SPEISER~ J. WEYERS) who made in 1973 the first oon- taots with some Zeoturers~ who~ on the advioe of NATO joined their efforts and worked in oommon. It was the 16th Summer Institute rd heZd at Cargese and the 3 one organized by the two departments of TheoreticaZ Physios at Leuven and Louvain-Za-Neuve. When the two groups decided (independentZy) on the subjeot of the sohooZ~ they oouZd not know how Zuoky their ohoioe eventuaZZy wouZd turn out to be : rareZy has it being possibZe to present an audienoe with suoh a great number of new and deoisive disooveries who are Zikely to stimuZate the imagination of theoreticians and the researoh projeots of experimentaZists aZike. Suoh were the decisive oonfirmation of the neutraZ ourrents~ the di-muon events~ the sZowZy deoaying new partioZes~ eto. The organizers were grate- JUZ indeed that they oouZd find physioists from aZmost alZ great oenters of high energy physios Who had themseZves participated in these disooveries. AZthough the theorists oouZd not matoh during the Zast two years the speotaouZar suooess of their experimentaZ ooZZeagues~ there has been enough important program~ especiaZZy in fieZd theory : renormaZization of gauge theories~ the mechanism disoovered by R. BROUT et aZ. ~ eto.

Speech by Toyosaburo Taniguchi Welcome my friends to the Third International Symposium, Division on the Theory of Condensed Matter, of the Taniguchi Foundation. The need is now greater than ever for Japan to consider how to strengthen and foster international understanding between nations, peoples and societies, and how to contribute towards the establishment of peace and prosperity in the world. For more than twenty years, I have been supporting a symposium on mathe matics in which distinguished scholars from allover the world have engaged in free discussions. In this symposium, all the participants live together in community style. I have heard from members of some of these study groups that this type of setup has helped to strengthen their ties and relationships with their colleagues on a personal basis. What developed in the mathematics group led me to reorganize and strengthen the Taniguchi Foundation only a few years ago through additional funding. In order to effectively translate the objectives of the Foundation into action with the funds available, it becomes necessary to select those fields which are not necessarily in the limelight of popular interest, which means those fields which, I am afraid, are low in funding. I would rather choose from modest unimpressive academic fields than for the Foundation, projects those that stand out in gaudy, gorgeous popular acclaim."

The advances in the theory of diffraction gratings and the applications of these results certainly determine the progress in several areas of applied science and engineering. The polarization converters, phase shifters and filters, quantum and solid-state oscillators, open quasi optical dispersive resonators and power compressors, slow-wave structures and patter forming systems, accelerators and spectrometer; that is still far from being a complete list of devices exploiting the amazing ability of periodic structures to perform controlled frequency, spatial, and polarization selection of signals.

Diffraction gratings used to be and still are one of the most popular objects of analysis in electromagnetic theory. The further development of the theory of diffraction gratings, in spite of considerable achievements, is still very important presently. The requirements of applied optics and microwave engineering present the theory of diffraction gratings with many new problems which force us to search for new methods and tools for their resolution. Just in such way there appeared recently new fields, connected with the analysis, synthesis and definition of equivalent parameters of artificial materials layers and coatings, having periodic structure and possessing features, which can be found in natural materials only in extraordinary or exceptional situations.

In this book the authors present results of the electromagnetic theory of diffraction gratings that may constitute the base of further development of this theory which can meet the challenges provided by the most recent requirements of fundamental and applied science.

The following issues will be considered in the book

• Authentic methods of analytical regularization, that perfectly match the requirements of analysis of resonant scattering of electromagnetic waves by gratings;
• Spectral theory of gratings, providing a reliable foundation for the analysis of spatial frequency transformations of electromagnetic fields occurring in open periodic resonators and waveguides;
• Parametric Fourier method and C-method, that are oriented towards the efficient numerical analysis of transformation properties of fields in the case of arbitrary profile periodic boundary between dielectric media and multilayered conformal arrays;
• Rigorous methods for analysis of transient processes and time-spatial transformations of electromagnetic waves in resonant situations, based on development and incorporation in standard numerical routines of FDTD of so called explicit absorbing boundary conditions;
• New approaches to the solution of homogenization problems the key problem arising in construction of metamaterials and meta surfaces;
• New physical results about the resonance scattering of pulse and monochromatic waves by periodic structures, including structures with chiral or left-handed materials;
• Methods and the results of the solutions of several actual applied problems of analysis and synthesis of pattern creating gratings, power compressors, resonance radiators of high capacity short radio pulses, open electromagnetic structures for the systems of resonant quasi optics and absorbing coatings.