During the last decade there has been an increasing interest in clusters and small particles because of the peculiar proper ties induced by their large area to volume ratio. For that reason small particles are often considered as an intermediate state of matter at the border between atomic (or molecular) chemistry, and physics of the condensed matter. The importance of the surface effect can explain the anomalous properties, for example the exis tence of the five fold symmetry observed in different circumstan ces '(beams of rare gas clusters, gold particles deposited on a substrate). However the question of the critical size at which the transition to bulk properties occurs cannot be simply answered, since the reply depends on the peculiar property which is studied. The importance of the size effect was emphasized in the last International Meetings. However the situation remains confused in most cases since the exact role of the cluster environment cannot be clearly elucidated and is a main difficulty, except in cluster beam experiments. In fact ideally free clusters constitute a labo ratory exception. In most applications small particles must be supported on a surface or embedded in a matrix, in order to be stabilized, which obviously shows the role of the environment."

Although it has long been possible to make organic materials emit light, it has only recently become possible to do so at the level and with the efficiency and control necessary to make the materials a useful basis for illumination in any but the most specialized uses. This book surveys the current status of the field.

One of the main goals of investigations of shock-wave phenomena in condensed matter is to develop methods for predicting effects of explosions, high-velocity collisions, and other kinds of intense dynamic loading of materials and structures. Based on the results of international research conducted over the past 30 years, this book is addressed not only to experts in shock-wave physics, but also to interested representatives from adjacent fields of activity and to students who seek an introduction to the current issues. With that goal in mind, the book opens with a brief account of the theoretical background and a short description of experimental techniques. The authors then progress to a systematic treatment of special topics, some of which have not been fully addressed in the literature to date.

The Institut Max-von-Laue-Paul Langevin (ILL) in Grenoble regularly organ ises workshops that deal with the various applications of neutrons in physics, chemistry, biology and also in nuclear physics. The workshop" Atomic Trans port and Defects in Metals by Neutron Scattering," jointly organised by the Institut Laue-Langevin and the Institut fiir Festkorperforschung of the KFA Jiilich, was held in October 1985 in Jiilich. The study of problems in metal physics and in physical metallurgy is a traditional field of neutron scattering. The most commonly used methods are diffuse elastic, small-angle and inelastic scattering of neutrons. A number of problems can be identified where neutrons yield information that is supple mentary to that from other methods such as x-ray diffraction, synchrotron radiation or electron microscopy. In certain fields, for example spectroscopy for the investigation of atomic motions or for the investigation of magnetic properties, neutron scattering is a unique method. The facilities at the High Flux Reactor of the ILL, and also at the Jiilich and at other medium flux research reactors, have contributed numerous re sults in these fields. It was the aim of this workshop to give a survey of the present state of neutron scattering in metal physics."

In interaction the between the leads to a quantum liquids particles variety of and unusual states of condensed matter interesting systems, super e.g. and the fractional in electron Hall effect conductivity quantum (FQHE) sys tems. In this book for we investigate quantum field theoretical approaches fermion the is interacting systems. Originally, quantum fieldtheory designed describe as a to perturbation theory weakly interacting many particle sys tems. For treatment of interaction and correlation effects a proper beyond the the series of must beresummed perturbation theory, Feynmandiagrams severalresummationschemeswhich the We on partially. present depend par ticular effect considered.We start with ofthe a physical compactdescription self consistent and the quantum fieldtheory approximations. conserving the of in fermion is caused two Superconductivity systems by interplay formation ofbound attractive interaction between the phenomena: pairsby fermions condensation ofthe low to and at temperatures leading long pairs order and We consider three dimensional of a range superfluidity. system fermionswith attractiveinteractionwhichshowsacrossoverfrom short range BCS to Bose Einstein condensation ofbound ifthe superconductivity pairs interaction is tuned fromweak to While the self coupling. strength strong consistent version ofthe is well suited to describe con quantum field theory densation of and a second resummation to the pairs superfluidity, leading the ofbound Bethe Salpeter equation describes formation pairs.

Springer-Verlag, Berlin Heidelberg, in conjunction with Springer-Verlag New York, is pleased to announce a new series: CRYSTALS Growth, Properties, and Applications The series presents critical reviews of recent developments in the field of crystal growth, properties, and applications. A substantial portion of the new series will be devoted to the theory, mechanisms, and techniques of crystal growth. Occasionally, clear, concise, complete, and tested instructions for growing crystals will be published, particularly in the case of methods and procedures that promise to have general applicability. Responding to the ever-increasing need for crystal substances in research and industry, appropriate space will be devoted to methods of crystal characterization and analysis in the broadest sense, even though reproducible results may be expected only when structures, microstructures, and composition are really known. Relations among procedures, properties, and the morphology of crystals will also be treated with reference to specific aspects of their practical application. In this way the series will bridge the gaps between the needs of research and industry, the pos sibilities and limitations of crystal growth, and the properties of crystals. Reports on the broad spectrum of new applications - in electronics, laser tech nology, and nonlinear optics, to name only a few - will be of interest not only to industry and technology, but to wider areas of applied physics as well and to solid state physics in particular. In response to the growing interest in and importance of organic crystals and polymers, they will also be treated."

Powders have been studied extensively because they arise in a wide variety of fields, ranging from soil mechanics to manufacture of pharmaceuticals. Only recently, however, with the deepening understanding of fractals, chaos, 1/f noise, and self-organization, has it been useful to study the mechanical properties of powders from a fundamental physical perspective. This book collects articles by some of the foremost researchers in the field, including chapters on: the role of entropy in the specification of a powder, by S.F. Edwards (Cambridge); discrete mechanics, by P.K. Haff (Duke); computer simulations of granular materials, by G.C. Barker (Norwich); pattern formation and complexity in granular flow, by R.P. Behringer and G.W. Baxter (Duke); avalanches in real sand piles, by A. Mehta (Birmingham); micromechanical models of failure, by M.J. Adams (Unilever) and B.J. Briscoe (Imperial College); mixing and segregation in particle flows, by J. Bridgwater (Birmingham); and hard-sphere colloidal suspensions, by P. Bartlett (Bristol) and W. van Megen (Melbourne).

The history of low dimensional conductors goes back to the prediction, more than forty years ago, by Peierls, of the instability of a one dimensional metallic chain, leading to what is known now as the charge density wave state. At the same time, Frohlich suggested that an "ideal" conductivity could be associated to the sliding of this charge density wave. Since then, several classes of compounds, including layered transition metal dichalcogenides, quasi one-dimensional organic conduc tors and transition metal tri- and tretrachalcogenides have been extensively studied. The molybdenum bronzes or oxides have been discovered or rediscovered as low dimensional conductors in this last decade. A considerable amount of work has now been performed on this subject and it was time to collect some review papers in a single book. Although this book is focused on the molybdenum bronzes and oxides, it has a far more general interest in the field of low dimensional conductors, since several of the molybdenum compounds provide, from our point of view, model systems. This is the case for the quasi one-dimensional blue bronze, especially due to the availability of good quality large single crystals. This book is intended for scientists belonging to the fields of solid state physics and chemistry as well as materials science. It should especially be useful to many graduate students involved in low dimensional oxides. It has been written by recognized specialists of low dimensional systems."

This book represents a collection of lectures presented at the NATO Advanced study Institute(ASI) on "Chemistry & Physics of the Molecular Processes in Energetic Materials," held at Hotel Torre Normanna, Altavilla Milicia, Sicily, Italy, September 3 to 15, 1989. The institute was attended by seventy participants including twenty lecturers, drawn from thirteen countries. The purpose of the institute was to review the major ad vances made in recent years in the theoretical and experi mental aspects of explosives and propellants. In accordance with the format of the NATO ASI, it was arranged to have a relatively small number of speakers to present in depth, re view type lectures emphasizing the basic research aspects of the subject, over a two week period. Most of the speakers gave two lectures, each in excess of one hour with addition al time for discussions. The scope of the meeting was limit ed to molecular and spectroscopic studies since the hydro dynamic aspects of detonation and various performance crite ria of energetic materials are often covered adequately in other international meetings. An attempt was made to have a coherent presentation of various theoretical, computational and spectroscopic approaches to help a better understanding of energetic materials from a molecular point of view. The progress already made in these areas is such that structure property (e. g."

The application of the Monte Carlo method to the simulation of semiconductor devices is presented. A review of the physics of transport in semiconductors is given, followed by an introduction to the physics of semiconductor devices. The Monte Carlo algorithm is discussed in great details, and specific applications to the modelling of semiconductor devices are given. A comparison with traditional simulators is also presented.

One of the ultimate goals of materials research is to develop a fun damental and predictive understanding of the physical and metallurgical properties of metals and alloys. Such an understanding can then be used in the design of materials having novel properties or combinations of proper ties designed to meet specific engineering applications. The development of new and useful alloy systems and the elucidation of their properties are the domain of metallurgy. Traditionally, the search for new alloy systems has been conducted largely on a trial and error basis, guided by the skill and intuition of the metallurgist, large volumes of experimental data, the principles of 19th century thermodynamics and ad hoc semi-phenomenological models. Recently, the situation has begun to change. For the first time, it is possible to understand the underlying mechanisms that control the formation of alloys and determine their properties. Today theory can begin to offer guidance in predicting the properties of alloys and in developing new alloy systems. Historically, attempts directed toward understanding phase stability and phase transitions have proceeded along distinct and seemingly diverse lines. Roughly, we can divide these approaches into the following broad categories. 1. Experimental determination of phase diagrams and related properties, 2. Thermodynamic/statistical mechanical approaches based on semi phenomenological models, and 3. Ab initio quantum mechanical methods. Metallurgists have traditionally concentrated their efforts in cate gories 1 and 2, while theoretical physicists have been preoccupied with 2 and 3."

This volume collects the contributions to the NATO Advanced Study Institute (ASI); "Computer Simulation in Materials Science -NanolMesolMacroscopic Space and Time Scales", held on lIe d'OIeron (France) June 6-16, 1995.1his event was intended to present the state of the art in simulation techniques in Materials Science. For decades to come the limits of computing power will not allow for atomistic simulations of macroscopic specimens. Simulations can only be performed on various scales (nano, meso, micro, macro) with the constitutive input provided by simulations (or data) on the next smaller scale. The resulting hierarchy has been the main topic of many of lectures and seminars. Necessarily, special emphasis was placed on mesoscopic simulations bridging the gaps between nano (atomic) and micro space and time scales. During the ASI, lecturers and participants did not only consider fundamental problems, but also applications. Papers on the evolution of morphological patterns in phase transformations and plastic deformation, irradiation effects, mass transport and mechanical properties of materials in general, highlighted what has already been achieved. It was concluded that computer simulations must be based on realistic and efficient models, the fundamental equations controlling the dynamical evolution of microstructures, stochastic field kinetic models being a case in point.

Relaxation phenomena of excited molecular states are abundant in all nature. They mediate such key processes as photochemical reactions or even the pathways of ordinary chemical reactions. However, for a long time the main research in electronic relaxation processes was concerned with anorganic solids, in part because of their great technological importance (photography, semiconductors ... ) in part also because these compounds were the "workhorses" of the solid state physicists. In the last 30 years, there was a steadily increasing interest in organic molecular systems, first in molecular crystals and later in all forms of molecular solids (glasses, polymers, membranes, ... ). The present volume combines papers on quite different types of relaxation phenomena: the type of solid studied, the electronic states involved, the physical processes responsible for the relaxations are all different. Nevertheless, after reading this book, a more clear and complete picture of the phenomenon "relaxa tion" emerges that proves that this volume is more than just a collection of individual articles. The volume starts with the paper "Spin-lattice and spin-spin relaxation in photo-excited triplet states in molecular crystals" by Jan Schmidt. Even in these seemingly simple systems of isolated guest molecules in a single crystal host, the relaxation phenomena are quite involved and a very thorough investigation is necessary to find the key relaxation processes. The end of the article provides a bridge to the following paper: it treats interactions of two molecules (dimers), where resonant interactions become important and lead to new, characteristic relaxation processes."

This book is the third volume in an approximately annual series which comprises the proceedings of the International Workshops on Condensed Matter Theories. The first of these meetings took place in 1977 in Sao Paulo, Brazil, and successive workshops have been held in Trieste, Italy (1978), Buenos Aires, Argentina (1979), Caracas, Venezuela (1980), Mexico City, Mexico (1981), St. Louis, USA (1982), Altenberg, Federal Republic of Germany (1983), Granada, Spain (1984), San Francisco, USA (1985), and Argonne, USA (1986). The present volume contains the proceedings of the Eleventh Workshop which took place in Qulu, Finland during the period 27 July - 1 August, 1987. The original motivation and the historical evolution of the series of Workshops have been amply described in the preface to the first volume in the present series. An important objective throughout has been to work against the ever-present trend for physics to fragment into increasingly narrow fields of specialisation, between which communication is difficult. The Workshops have traditionally sought to emphasise the unity of physics. By bringing together scientists working in many different areas of condensed matter theory, for the dual purpose of fostering collaborations between them and promoting the exchange of ideas between various disciplines, a common language has been exposed and developed. The Editor of the first volume in the series, F. B.

This book contains the proceedings of the International "Workshop on 3D Process Simulation which was held at the Campus of the University Erlangen-Nuremberg in Erlangen on September 5, 1995, in conjunction with the 6th International Conference on "Simulation of Semiconductor Devices and Processes (SISDEP 95). Whereas two-dimensional semiconductor process simulation has achieved a certain degree of maturity, three-dimensional process simulation is a newly emerging field in which most efforts are dedicated to necessary basic developments. Research in this area is promoted by the growing demand to obtain reliable information on device geometries and dopant distributions needed for three-dimensional device simulation, and challenged by the great algorithmic problems caused by moving interfaces and by the requirement to limit computation times and memory requirements. This workshop provided a forum to discuss the industrial needs, technical problems, and solutions being developed in the field of three-dimensional semiconductor process simulation. Invited presentations from leading semiconductor companies and research Centers of Excellence from Japan, the USA, and Europe outlined novel numerical algorithms, physical models, and applications in this rapidly emerging field.

The control of optical modes in microcavities or in photonic bandgap (PBG) materials is coming of age! Although these ideas could have been developed some time ago, it is only recently that they have emerged, due to advances in both atomic physics and in fabrication techniques, be it on the high-quality dielectric mirrors required for high-finesse Fabry Perot resonators or in semiconductor multilayer deposition methods. Initially the principles of quantum electro-dynamics (QED) were demonstrated in elegant atomic physics experiments. Now solid-state implementations are being investigated, with several subtle differences from the atomic case such as those due to their continuum of electronic states or the near Boson nature of their elementary excitations, the exciton. Research into quantum optics brings us ever newer concepts with potential to improve system performance such as photon squeezing, quantum cryptography, reversible taps, photonic de Broglie waves and quantum computers. The possibility of implementing these ideas with solid-state systems gives us hope that some could indeed find their way to the market, demonstrating the continuing importance of basic research for applications, be it in a somewhat more focused way than in earlier times for funding.

This book gives an account of a number of recent developments in two different subfields of research, optics and micro--electronics. The leading principle in presenting them together in one book is the striking similarity between a variety of notions in these two research areas. We mention in this respect tunneling, quantum interference and localization, which are important concepts in quantummechanics and more specifically in condensed matter physics. Miniaturization in solid state engineering has led to new phenomena in which these concepts play their significant roles. As it is the wave character of electrons which is strongly emphasized in these phenomena one's attention is quite naturally directed to the field of optics in which the above quantum-mechanical notions all seem to have their direct classical wavemechanical counterparts. Both micro--electronics and optics have been and still are in a mode of intensifying activity. The possibilities to technically "translate" devices developed within one research field to similar devices in the other field are strongly increasing. This opens, among other things, a door leading to "quantummechanics" on a macroscopic scale with visible light under relatively easily accessible experimental conditions, or to "wave optics II in the domain of solid state physics. Thinking in terms of analogies is important anyhow, but it is especially the cross-fertilization between optics and micro--electronics which according to the editors will lead to deepened insights and a new type of technology.

We present here the transcripts of lectures and talks which were delivered at the NATO ADVANCED STUDY INSTITUTE "Electronic Structure of Complex Systems" held at the State University of Ghent, Belgium during the period July 12-23, 1982. The aim of these lectures was to highlight some of the current progress in our understanding of the electronic structure of com plex systems. A massive leap forward is obtained in bandstructure calculations with the advent of linear methods. The bandtheory also profitted tremendously from the recent developments in the density functional theories for the properties of the interacting electron gas in the presence of an external field of ions. The means of per forming fast bandstructure calculations and the confidence in the underlying potential functions have led in the past five years or so to a wealth of investigations into the electronic properties of elemental solids and compounds. The study of the trends of the electronic structure through families of materials provided invalu able insights for the prediction of new materials. The detailed study of the electronic structure of specific solids was not neglected and our present knowledge of d- and f-metals and metal hydrides was reviewed. For those systems we also investi gated the accuracy of the one electron potentials in fine detail and we complemented this with the study of small clusters of atoms where our calculations are amenable to comparison with the frontiers of quantum chemistry calculations."

I would like to present to a wide circle of the readers working in quantum chem- istry and solid-state physics, as ,,*ell as in other fields of many-body physics and its interfaces, this book deyoted to density functional theory written by my colleagues Eugene S. Kryachko and Eduardo Y. Ludena. Their ways to this theory are rather different although basically both of them are quantum chemical. Eugene S. Kryachko came to energy density functional theory from the theory of reduced density matrices, and Eduardo \'. Ludena dewloped earlier the concept of loges in quantum chemistry. Neyertheless, their earlier interests giw the possibility to consolidate and formulate energy density functional theory in a unified and consistent way, in my opinion. Raymond Daudel Paris ACKNOWLEDGMENTS The authors are indebted to Carl Almbladh, Victor Va. Antonchenko, John Avery, Richard F. W. Bader, Ulf \'on Barth, Jean-Louis Calais, A. John Coleman, Jens P. Dahl, Robert Donnelly, Harold Englisch, Robert 1\1. Erdahl, Oswaldo Goscinski, John E. Harriman, Gintas Kamuntavichius, Illja G. Kaplan, Jaime Keller, \'alentin Khart- siev, Toshikatsu Koga, Per-Olov Lo\ydin, T. Tung Nguyen-Dang, Ivan Zh. Petkov, Jerome K. Percus, l\lary Beth Ruskai, John R. Sabin, Zdenek Slanina, \'ladimir Shi- rokov, l\lario V. Stoitsov, Yoram Tal, and \Vaitao Yang, who in one way or another, either through their kind support, help, discussions or valuable comments created the human and intellectual background which made this book possible.

The 6th course of the futernational School of Solid State Physics was held in Erice, Sicily, at the Ettore Majorana Centre for Scientific Culture, 19-29 June, 1995. The course was organized as a NATO Advanced Study Institute and received generous support from NATO's Nanoscale Science Program. This volume is based on the lectures presented during the course. fudispensable for the planning of the summer school was the support of the Director of the Ettore Majorana Centre, Professor A. Zichichi. We wish to express our sincere appreciation to the center staff, Dr. Maria Zaini, Dr. Alberto Gabriele, Dr. Pinola Savalli and Dr. Jerry Pilarski for their expert assistance in all organizational matters. A special word of thanks must go to the director of the International School of Solid State Physics, Professor Giorgio Benedek, not only for his valuable advice in the planning stage, but also for his active participation in the program itself. I would like to thank my coworkers, Stefan Frank, Nikola Malinowski, Renee Stotz, Frank Tast and Kristin Wirth for their valuable assistance in preparing these proceedings of the meeting. The success of a school is, in the last analysis, determined by the inter- est and commitment of the lecturers and participants. I am very grateful to the lecturers for their carefully prepared formal presentations, to the par- ticipants for their contributions to the spontaneous evening "workshops", and to all for their inexhaustible enthusiasm.

This book is a course of lectures given for senior students at the Moscow Institute of Physics and Technology. For those who have graduated in the USSR this information should beisufficient to give an idea of the level and the manner in which the subject matter is presented. On the other hand, readers outside of this country may never have heard about this well-known Sgviet institution, and so we would like to say few words about it now. The Moscow Institute of Physics and Technology (MFTI or Fiztekh) was founded in 1947 as the result of a special directive of Stalin in order to supply the space and nuclear program with highly educated experts. The best scientists in the country were involved in the foundation process. They invented an effective and flexible educational system that includes basic education accord ing to an university program followed by specialization at lead ing scientific centers. Being organized initially as a department of Moscow State University, MFTI recently separated into an inde pendent institution. In the sixties it lost its mainly top secret and military character and became the most prestigious place in the country for an education in physics. The political changes of the last few years have opened it to contacts with other countries. The course of lectures comprising this book is dedicated to the subject of the intense resonant interaction of laser radiation. with matter and contains a significant part of the Ph. D."

"Granular Gases" are diluted many-particle systems in which the mean free path of the particles is much larger than the typical particle size, and where particle collisions occur dissipatively. The dissipation of kinetic energy can lead to effects such as the formation of clusters, anomalous diffusion and characteristic shock waves to name but a few. The book is organized as follows: Part I comprises the rigorous theoretical results for the dilute limit. The detailed properties of binary collisions are described in Part II. Part III contains experimental investigations of granular gases. Large-scale behaviour as found in astrophysical systems is discussed in Part IV. Part V, finally, deals with possible generalizations for dense granular systems.

Understanding the origin of spatio-temporal order in open systems far from thermal equilibrium and the selection mechanisms of spatial struc tures and their symmetries is a major theme of present day research into the structures of continuous matter. The development of methods for pro ducing spatially ordered microstructures in solids by non-equilibrium methods opens the door to many technological applications. It is also be lieved that the key to laminar/turbulence transitions in fluids lies in the achievement of spatio-temporal order. Let us also emphasize the fact that the idea of self-organization in it self is at the origin of a reconceptualisation of science. Indeed, the appear ance of order which usually has been associated with equilibrium phase transitions appears to be characteristic of systems far from thermal equi librium. This phenomenon which was considered exceptional at first now the rule in driven systems. The chemical oscillations obtained appears to be in the Belousov-Zhabotinskii reaction were initially considered to be ther modynamically impossible and were rejected by a large number of chemists. Now these oscillations and related phenomena (waves, chaos, etc. ) are the subject of intensive research and new classes of chemical oscil lators have been recently discovered. Even living organisms have long been considered as the result of chance rather than necessity. Such points of view are now abandoned under the overwhelming influence of spatio-tem poral organization phenomena in various domains ranging from physics to biology via chemistry, nonlinear optics, and materials science ."

This status report features the most recent developments in the field, spanning a wide range of topical areas in the computer simulation of condensed matter/materials physics. Highlights of this volume include various aspects of non-equilibrium statistical mechanics, studies of properties of real materials using both classical model simulations and electronic structure calculations, and the use of computer simulation in teaching.

Low-dimensional semiconductor quantum structures are a major, high-technological development that has a considerable industrial potential. The field is developing extremely rapidly and the present book represents a timely guide to the latest developments in device technology, fundamental properties, and some remarkable applications. The content is largely tutorial, and the book could be used as a textbook. The book deals with the physics, fabrication, characteristics and performance of devices based on low-dimensional semiconductor structures. It opens with fabrication procedures. The fundamentals of quantum structures and electro-optical devices are dealt with extensively. Nonlinear optical devices are discussed from the point of view of physics and applications of exciton saturation in MQW structures. Waveguide-based devices are also described in terms of linear and nonlinear coupling. The basics of pseudomorphic HEMT technology, device physics and materials layer design are presented. Each aspect is reviewed from the elementary basics up to the latest developments. Audience: Undergraduates in electrical engineering, graduates in physics and engineering schools. Useful for active scientists and engineers wishing to update their knowledge and understanding of recent developments.