This book aims at providing graduate students and researchers with funda mental knowledge indispensable for entering the new field of "microclus 3 ters." Microclusters consisting of 10 to 10 atoms exhibit neither the pro perties of the corresponding bulk nor those of the corresponding molecule of a few atoms. The microclusters may be considered to form a new phase of materials lying between macroscopic solids and microscopic particles such as atoms and molecules, showing both macroscopic and microscopic features. However, research into such"a riew phase has been left untouched until recent years by the development of the quantum theory of matter. The microscopic features of microclusters were first revealed by ob serving anomalies of the mass spectrum of a Na cluster beam at specific sizes, called magic numbers. Then it was experimentally confirmed that the magic numbers come from the shell structure of valence electrons. Being stimulated by these epoch-making findings in metal microclusters and aided by progress of the experimental techniques producing relatively dense, non interacting micro clusters of various sizes in the form of micro cluster beams, the research field of microclusters has developed rapidly in these 5 to 7 years. The progress is also due to the improvement of computers and com putational techniques, which have made it possible to perform ab initio cal culations of the atomic and electronic structure of smaller microclusters, as well as to carry out computer simulations of their dynamics."

The state-of-the-art in the theoretical statistical physics treatment of the Janus fluid is reported with a bridge between new research results published in journal articles and a contextual literature review. Recent Monte Carlo simulations on the Kern and Frenkel model of the Janus fluid have revealed that in the vapor phase, below the critical point, there is the formation of preferred inert clusters made up of a well-defined number of particles: the micelles and the vesicles. This is responsible for a re-entrant gas branch of the gas-liquid binodal. Detailed account of this findings are given in the first chapter where the Janus fluid is introduced as a product of new sophisticated synthesis laboratory techniques. In the second chapter a cluster theory is developed to approximate the exact clustering properties stemming from the simulations. It is shown that the theory is able to reproduce semi-quantitatively the micellization phenomenon.

An exciton is an electronic excitation wave consisting of an electron-hole pair which propagates in a nonmetallic solid. Since the pioneering research of Fren kel, Wannier and the Pohl group in the 1930s, a large number of experimental and theoretical studies have been made. Due to these investigations the exciton is now a well-established concept and the electronic structure has been clarified in great detail. The next subjects for investigation are, naturally, dynamical processes of excitons such as excitation, relaxation, annihilation and molecule formation and, in fact, many interesting phenomena have been disclosed by recent works. These excitonic processes have been recognized to be quite important in solid-state physics because they involve a number of basic interactions between excitons and other elementary excitations. It is the aim of this quasi monograph to describe these excitonic processes from both theoretical and experimental points of view. we take a few To discuss and illustrate the excitonic processes in solids, important and well-investigated insulating crystals as playgrounds for excitons on which they play in a manner characteristic of each material. The selection of the materials is made in such a way that they possess some unique properties of excitonic processes and are adequate to cover important interactions in which excitons are involved. In each material, excitonic processes are described in detail from the experimental side in order to show the whole story of excitons in a particular material."

Trends in Computational Nanomechanics reviews recent advances in analytical and computational modeling frameworks to describe the mechanics of materials on scales ranging from the atomistic, through the microstructure or transitional, and up to the continuum. The book presents new approaches in the theory of nanosystems, recent developments in theoretical and computational methods for studying problems in which multiple length and/or time scales must be simultaneously resolved, as well as example applications in nanomechanics.

This title will be a useful tool of reference for professionals, graduates and undergraduates interested in Computational Chemistry and Physics, Materials Science, Nanotechnology.

Computer Simulation Studies in Condensed-Matter Physics VIII covers recent developments in this field presented at the 1995 workshop, such as new algorithms, methods of analysis, and conceptual developments. This volume is composed of three parts. The first part contains invited papers that deal with simulational studies of classical systems. The second part is devoted to invited papers on quantum systems, including new results for strongly correlated electron and quantum spin models. The final part comprises contributed presentations.

We are pleased to present the ?fth volume of Progress in Ultrafast Intense LaserScience.Asthefrontiersofultrafastintenselasersciencerapidlyexpand ever outward, there continues to be a growing demand for an introduction to this interdisciplinary research ?eld that is at once widely accessible and ca- ble of delivering cutting-edge developments. Our series aims to respond to this call by providing a compilation of concise review-style articles written by researchers at the forefront of this research ?eld, so that researchers with d- ferent backgrounds as well as graduate students can easily grasp the essential aspects. As in the previous volumes of PUILS, each chapter of this book begins with an introductory part, in which a clear and concise overview of the topic and its signi?cance is given, and moves onto a description of the authors' most recent research results. All the chapters are peer-reviewed. The articles ofthis?fth volumecovera diverserangeofthe interdisciplinaryresearch?eld, and the topics may be grouped into three categories: coherent responses of gaseousand condensed matter to ultrashortintense laser pulses (Chaps. 1-4), propagationof intense laser pulses (Chaps. 5, 6), and laser-plasma interaction and its applications (Chaps. 7-10). From the third volume, the PUILS series has been edited in liaison with the activities of Center for Ultrafast Intense Laser Science in The University of Tokyo, and JILS (Japan Intense Light Field Science Society), the latter of which has also been responsible for sponsoring the series and making the regularpublicationofitsvolumespossible.Fromthe presentvolume,the C- sortiumonEducationandResearchonAdvancedLaserScience,theUniversity of Tokyo, joins this publication activity as one of the sponsoring programs.

The Fourth USA-USSR Symposium. on The Physics of Optical Phenomena and Their Use as Probes of Matter, was held in Irvine, California, January 23-27, 1990. Participating in the Symposium were 22 scientists from the USSR and 29 from the USA. In addition, to provide an international dimension to this Symposium without, however, compromising significantly its essentially binational character, 7 non-US and non-USSR scientists were invited to take part in it. The present volume is the proceedings of that Symposium, and contains all manuscripts received prior to August 1, 1990, representing. scientific contributions presented. A few manuscripts were not received, but for completeness the corresponding abstract is printed.. Three previous USA/USSR Binational Symposia on related topics have been held, viz. "Theory of Light Scattering in Condensed Matter" (Moscow, 1975), "Light Scattering in Solids" (New York, 1979), and "Laser Optics of Condensed Matter" (Leningrad, 1987). These meetings were evaluated by the participants as highly successful and provided invaluable oppor tunities for researchers to exchange information and to initiate colla borative work which led to research visits by US physicist to Soviet laboratories, and vice versa, and which continue to the present day.

This is the first volume of a series of books that will describe current advances and past accompli shments of mathemat i ca 1 aspects of nonlinear sCience taken in the broadest contexts. This subject has been studied for hundreds of years, yet it is the topic in whi ch a number of outstandi ng di scoveri es have been made in the past two decades. Clearly, this trend will continue. In fact, we believe some of the great scientific problems in this area will be clarified and perhaps resolved. One of the reasons for this development is the emerging new mathematical ideas of nonlinear science. It is clear that by looking at the mathematical structures themselves that underlie experiment and observation that new vistas of conceptual thinking lie at the foundation of the unexplored area in this field. To speak of specific examples, one notes that the whole area of bifurcation was rarely talked about in the early parts of this century, even though it was discussed mathematically by Poi ncare at the end of the ni neteenth century. I n another di rect ion, turbulence has been a key observation in fluid dynamics, yet it was only recently, in the past decade, that simple computer studies brought to light simple dynamical models in which chaotic dynamics, hopefully closely related to turbulence, can be observed.

Strutural Analysis of Point Defects in Solids introduces the principles and techniques of modern electron paramagnetic resonance (EPR) spectroscopy essentialfor applications to the determination of microscopic defect structures. Investigations of the microscopic and electronic structure, and also correlations with the magnetic propertiesof solids, require various multiple magnetic resonance methods, such as ENDOR and optically detected EPR or ENDOR. This book discusses experimental, technological and theoretical aspects of these techniques comprehensively, from a practical viewpoint, with many illustrative examples taken from semiconductors and other solids. The nonspecialist is informed about the potential of the different methods, while the researcher faced with the task of determining defect structures isprovided with the necessary tools, together with much information on computer-aided methods of data analysis and the principles of modern spectrometer design.

Interacting many-body systems are the main subjects of research in theoretical condensed matter physics, and they are the source of both the interest and the difficulty in this field. In order to understand the macroscopic properties of matter in terms of macroscopic knowledge, many analytic and approximate methods have been introduced. The contributions to this proceedings volume focus on the most recent developments of computational approaches in condensed matter physics. Monte Carlo methods and molecular dynamics simulations applied to strongly correlated classical and quantum systems such as electron systems, quantum spin systems, spin glassss, coupled map systems, polymers and other random and comlex systems are reviewed. Comprising easy to follow introductions to each field covered and also more specialized contributions, this proceedings volume explains why computational approaches are necessary and how different fields are related to each other.

Both an introductory course to broadband dielectric spectroscopy and a monograph describing recent dielectric contributions to current topics, this book is the first to cover the topic and has been hotly awaited by the scientific community.

In view of its extreme complexity the mathematical description of the mechanical behaviour of granular materials is an extremely difficult task. Today many different models compete with each other. However, the complexity of the models hinders their comparison, and the potential users are confused and, often, disencouraged. This book is expected to serve as a milestone in the present situation, to evaluate the present methodes, to clear up the situation, to focus and encourage for further research activities.

Over the past ten years liquid crystals have attracted much interest and considerable progress has been made with respect to our knowledge in this field. The recent development was initiated mainly by the work of J. L. Fergason and G. H. Heilmeier, who pointed out the importance of liquid crystals for thermographic and electro optic applications. The first part of this book is a brief introduction to the physics of liquid crystals. The structures and properties of the three basic types of liquid crystals are discussed. A special paragraph is devoted to electric-field effects, which are important in display applications. The chapter on Scientific Applications gives an insight into the potential applications of liquid crystals in fundamental research, with special emphasis on explaining the principles involved. Two groups of potential applications are discussed in detail: 1. the use of liquid crystals as anisotropic solvent for the determination of molecular properties by means of spectroscopy, and 2. their use in analytical chemistry, particularly in gas chromatography. The reverse process involves the use of the dissolved molecules as microscopic probes in the investigation of the dynamical molecular structure of anisotropic fluid systems (e.g. biological membranes). This extremely important technique is also described."

At the present moment, after the success of the renormalization group in providing a conceptual framework for studying second-order phase tran sitions, we have a nearly satisfactory understanding of the statistical me chanics of classical systems with a non-random Hamiltonian. The situation is completely different if we consider the theory of systems with a random Hamiltonian or of chaotic dynamical systems. The two fields are connected; in fact, in the latter the effects of deterministic chaos can be modelled by an appropriate stochastic process. Although many interesting results have been obtained in recent years and much progress has been made, we still lack a satisfactory understanding of the extremely wide variety of phenomena which are present in these fields. The study of disordered or chaotic systems is the new frontier where new ideas and techniques are being developed. More interesting and deep results are expected to come in future years. The properties of random matrices and their products form a basic tool, whose importance cannot be underestimated. They playa role as important as Fourier transforms for differential equations. This book is extremely interesting as far as it presents a unified approach for the main results which have been obtained in the study of random ma trices. It will become a reference book for people working in the subject. The book is written by physicists, uses the language of physics and I am sure that many physicists will read it with great pleasure."

Mixed valency is one of various names used to describe compounds which contain ions of the same element in two different formal states of oxidation. The existence of mixed valency systems goes far back into the geological evolutionary history of the earth and other planets, while a plethora of mixed valency minerals has attracted attention since antiquity. Indeed, control of the oxidation states of Fe in its oxides (FeO, Fe304' Fe203) was elegantly used in vase painting by the ancient Greeks to produce the characteristic black and red Attic ceramics (Z. Goffer, "Archaeological Chemistry," Wiley, New York, 1980). It was, however, only 25 years ago that two reviews of mixed valency appeared in the literature almost simultaneously, signalling the first attempt to treat mixed valency systems as a separate class of compounds whose properties can be correlated with the molecular and the electronic structure of their members. Then mixed valency phenomena attracted the interest of disparate classes of scientists, ranging from synthetic chemists to solid state physicists and from biologists to geologists. This activity culminated with the NATO ASI meeting in Oxford in 1979. The 1980's saw again a continuing upsurge of interest in mixed valency. Its presence is a necessary factor in the search for highly conducting materials, including molecular metals and superconductors. The highly celebrated high T c ceramic superconducting oxides are indeed mixed valency compounds.

This volume contains a collection of review articles that are extended versions of invited lectures given at the First Pamporovo Winter Workshop on Cooperative Phe nomena in Condensed Matter held in villa "Orlitza" (7th-15th March 1998, Pamporovo Ski Resort, Bulgaria). Selected research works reported at the Workshop have been published in the Journal of Physical Studies - a new International Journal for research papers in experimental and theoretical physics (Lviv University, Lviv, Ukraine). These reviews are supposed to be status reports and present new insights gained from the rapidly developing research of outstanding problems in condensed matter physics such as structural properties and phase transitions in fullerene crystals, super conductivity ofstrongly interacting electrons in copper oxides, spin polarized Fermi liq uids, chaotic vortex filaments in superfluid turbulent Helium-II, desorption induced by electronic transitions in ionic compounds, fluctuation phenomena in superconductors, and quantum critical phenomena in low dimensional magnets and quantum liquids. We have set the material according to the alphabetic order of authors' names although the high temperature superconductivity seems to be the hard kernel in condensed matter physics. The authors have taken care to present the recent advances in their research in a form which is readable and useful not only to experts in the respective field, but also to young scientists. That is why the lectures include a comprehensive introduction to the matter and also an extended discussion of methodical details.

The International Workshop on Coherent Control of Carrier Dynamics in Semiconductors was held May 19 to 22, 1998 at the University of Illinois at Chicago. Its intent was to bring together an international and interdisciplinary group of scientists to discuss recent progress, pertinent problems, and open questions in the field of coherent control in atoms, molecules, and semiconductors, in particular. Twenty-seven scientists from the physical chemistry, quantum optics, semiconductor, electrical engineering, and laser communities accepted our invitation and made this event a meeting of exciting presentations and vivid discussions. This volume contains the proceedings of this workshop. Most speakers accepted our invitation to provide a manuscript either on specific aspects of their work or a brief review of their area of research. All manuscripts were reviewed. It is hoped that they provide not merely an overview of most of the issues covered during the workshop, but also represent an account of the current state of coherent control in general. Hence, it is hoped that they are also of interest to a large number of scientists active in one of the areas listed above. The organizers of this workshop would like to thank all the participants for making this meeting a complete success. We are particularly indebted to Dr. Larry R. Cooper at the U.S. Office of Naval Research and Dr.

The International Winter School on Electronic Properties of Polymers and Re- lated Compounds, held March 11-18, 1989, in Kirchberg (Austria), was a sequel to two meetings on similar subjects held there two and four years be- fore. The 1989 winter school was again organized in cooperation with the "Bundesministerium flir Wissenschaft und Forschung" in Austria, and with the "Bundesministerium fUr Forschung und Technologie" in the Federal Republic of Germany. The basic idea of the meeting was to provide an opportunity for experienced scientists from universities and industry to discuss their most recent results and for students and young scientists to become familiar with the present status of research and applications in the field. Like the previous winter schools, this one concentrated on the electronic structure and application potentialities of polymers. A purely tutorial contribu- tion on high-temperature supercondutors was included. Special attention was paid this time to our present theoretical understanding of the electronic struc- ture of polymers in general, the role of disorder and the nature of the doping process in particular. Accordingly, two discussion meetings were held on the stability of quasiparticles in conjugated polymers and on the thermochromic phase transition in alkylated thiophenes. As a general result, disorder and con- jugation length were recognized as fundamental properties, not only for the stability of the quasiparticles but also for linear and nonlinear optics, transport, phototransport, magnetic properties, lattice dynamics, etc.

Real problems concerning vibrations of elastic structures are among the most fascinating topics in mathematical and physical research as well as in applications in the engineering sciences. This book addresses the student familiar with the elementary mechanics of continua along with specialists. The authors start with an outline of the basic methods and lead the reader to research problems of current interest. An exposition of the method of spectra, asymptotic methods and perturbation is followed by applications to linear problems where elastic structures are coupled to fluids in bounded and unbounded domains, to radiation of immersed bodies, to local vibrations, to thermal effects and many more.

Crystal pulling is an industrial process and provides the bulk of semiconductor crystals for the semiconductor industry. Initially a purely empirical process, the increase in importance and size of the industry has led to basic research into the fundamentals of the process - particularly the modelling of heat and mass transfer. The book has been written by the recognized authority on Czochralski crystal-growth techniques. It is an attempt to strengthen the interface between the practical crystal grower and the applied mathematician involved in analytical and computer modelling. Its focus is on the physics, chemistry and metallurgy of the process. From reviews: "... There is a need for a modern, non-trivial text on Czochralski growth ... and Dr. Hurle is eminently suited to write such a text."; "Dr. Hurle is probably uniquely qualified to write a book on ... (the Czochralski) growth process. ... He has published a great deal of very substantial as well as innovative work in this area."

In the 1950s the direct observation of dislocations became possible, stimulat ing the interest of many research workers in the dynamics of dislocations. This led to major contributions to the understanding of the plasticity of various crys talline materials. During this time the study of metals and alloys of fcc and hcp structures developed remarkably. In particular, the discovery of the so-called in ertial effect caused by the electron and phonon frictional forces greatly influenced the quantitative understanding of the strength of these metallic materials. Statis tical studies of dislocations moving through random arrays of point obstacles played an important role in the above advances. These topics are described in Chaps. 2-4. Metals and alloys with bcc structure have large Peierls forces compared to those with fcc structure. The reasons for the delay in studying substances with bcc structure were mostly difficulties connected with the purification techniques and with microscopic studies of the dislocation core. In the 1970s, these difficulties were largely overcome by developments in experimental techniques and computer physics. Studies of dislocations in ionic and covalent bonding materials with large Peierls forces provided infonnation about the core structures of dislocations and their electronic interactions with charged particles. These are the main subjects in Chaps. 5-7."

The contribution of computer simulation studies to our understanding of the prop erties of a wide range of condensed matter systems is now weIl established. The Center for Simulational Physics of the University of Georgia has been hosting a series of annual workshops with the intent of bringing together experienced prac titioners in the field, as weIl as relative newcomers, to provide a forum for the exchange of ideas and recent results. This year's workshop, the third in the series, was held February 12-16, 1990. These proceedings are arecord of the workshop and are published with the goal of timely dissemination of the papers to a wider audience. The proceedings are divided into four parts. The first contains invited pa pers dealing with simulational studies of classical systems and also includes an introduction to some new simulation techniques. Aseparate section is devoted to invited papers on quantum systems, including new results for strongly correlated electron and quantum spin models believed to be important for the description of high-Tc superconductors. The third part consists of a single invited paper, which presents a comprehensive treatment of issues associated with high perfor mance computing, including differences in architectures and a discussion of access strategies. The contributed papers constitute the final part.

This book is an introduction to the physics of elementary excitations in condensed matter with emphasis on basic concepts and their mathematical representations. The nature of the book is mainly determined by the fact that it was originally written, in Japanese, as one volume of Iwanami Series of Fundamental Physics supervised by Professor H. Yukawa. Our task was to portray the theory of condensed matter from a unified point of view for the student looking for his own research field and also for more senior readers interested in fundamentals of contemporary physics. As our point of view, we chose the concept of elementary excitation, which we believe to be one of the most fruitful concepts discovered by the quantum theory of matter. The present English edition has been translated by the authors themselves from the second, revised Japanese edition published in 1978, six years after publication of the first edition. In translating, we have introduced no major modifications; only the list of references has been made more suitable to overseas readers. In the English as well as in the Japanese editions, Chaps. 1,4, and part of 6 were written by Nakajima, Chaps. 2, 5, and 7 by Toyozawa, and Chaps. 3 and part of 6 by Abe. Finally we should like to thank Professor P. Fulde for kind help and Dr. H. Lotsch, SpriIiger-Verlag, for patient cooperation in making this English edition a reality.

This book is based on the results of many years of experimental work by the author and his colleagues, dealing with the electronic properties of organic crystals. E. Silinsh has played a leading role in pOinting out the importance of the polarization energy by an excess carrier, in determining not only the character of the carrier mobility in organic crystals, but in determining the band gap and the nature of the all-important trapping site in these crystals. The one-electron model of electronic conductivity that has been so successful in dealing with inorganic semiconductors is singular ly unsuccessful in rationalizing the unusual physical properties of organic crystals. A many-body theory is required, and the experimental manifestation of this is the central role played by the crystal polarization enerqies in transferring the results obtained with the isolated molecule, to the solid. The careful studies of E. Silinsh in this field have shown tn detail how this polarization energy develops around the excess carrier (and also the hole-electron pair) sitting on a molecular site in the crystal. As with all insulators, trapping sites playa dominant role in reducing the magnitude of he current that can theoretically pass through the organic crystal. It is usually the case that these trapping sites are energetically distributed within the forbidden band of the crystal. For many years, an exponential distribution has shown itself to be useful and reasonably correct: However, ' E."