Magnetism encompasses a wide range of systems and physical phenomena, and its study has posed and exposed both important fundamental problems and many practical applications. Recently, several entirely new phenomena have thus been discovered, generated through cooperative behaviour which could not have been predicted from a knowledge of `one-spin' states. At the same time, advances in sample preparation, experimental technique, apparatus and radiation sources, have led to increasing precision in the investigation and exposure of greater subtleties in magnetic thin films, multilayers and other systems. Examples of unexpected and conceptually new phenomena occur in strongly correlated and fluctuating quantum systems, producing effects such as Haldane and spin-Peierls gaps, solitons, quantum spin glasses and spin liquids. The discovery and elucidation of these `emerging properties' is a central theme in modern condensed matter physics. The present book comprises a series of chapters by world experts, covering both theoretical and experimental aspects. The approach is pedagogical and tutorial, but fully up to date, covering the latest research. The level is appropriate to graduate researchers who may either be just moving into the field or who are already active in condensed matter physics.

This volume comprises the proceedings of a NATO Advanced Study Institute held at Geilo, Norway, 24 March - 3 April 2003, the seventeenth ASI in a series held every two years since 1971. The objective of this ASI was to identify and discuss areas where synergism between modern physics, soft condensed matter and biology might be most fruitful. The main pedagogical approach was to have lecturers focussing on basic understanding of important aspects of the relative role of the various interaction- electrostatic, hydrophobic, steric, conformational, van der Waals etc. Soft condensed matter and the connection between physics and biology have been the themes of several earlier Geilo Schools. A return to these subjects thus allowed a fresh look and a possibility for defining new directions for research. Examples of soft materials, which were discussed at this ASI, included colloidal dispersions, gels, biopolymers and charged polymer solutions, polyelectrolytes, protein/membrane complexes, nucleic acids and their complexes. Indeed, most forms of condensed matter are soft and these substances are composed of aggregates and macromolecules, with interactions that are too weak and complex to form crystals spontaneously. A characteristic feature is that small external forces, slight perturbations in temperature, pressure or concentration, can all be enough to induce significant structural changes. Thermal fluctuations are almost by definition strong in soft materials and entropy is a predominant determinant of structure, so that disorder, slow dynamics and plastic deformation are the rule. Hence the phrase 'soft condensed matter' has been coined.

This volume comprises the proceedings of a NATO Advanced Study Institute held at Geilo, Norway, 24 March - 3 April 2003, the seventeenth ASI in a series held every two years since 1971. The objective of this ASI was to identify and discuss areas where synergism between modern physics, soft condensed matter and biology might be most fruitful. The main pedagogical approach was to have lecturers focussing on basic understanding of important aspects of the relative role of the various interaction- electrostatic, hydrophobic, steric, conformational, van der Waals etc. Soft condensed matter and the connection between physics and biology have been the themes of several earlier Geilo Schools. A return to these subjects thus allowed a fresh look and a possibility for defining new directions for research. Examples of soft materials, which were discussed at this ASI, included colloidal dispersions, gels, biopolymers and charged polymer solutions, polyelectrolytes, protein/membrane complexes, nucleic acids and their complexes. Indeed, most forms of condensed matter are soft and these substances are composed of aggregates and macromolecules, with interactions that are too weak and complex to form crystals spontaneously. A characteristic feature is that small external forces, slight perturbations in temperature, pressure or concentration, can all be enough to induce significant structural changes. Thermal fluctuations are almost by definition strong in soft materials and entropy is a predominant determinant of structure, so that disorder, slow dynamics and plastic deformation are the rule. Hence the phrase 'soft condensed matter' has been coined.

This volume comprises the proceedings of a NATO Advanced Study In stitute held at Geilo, Norway, April 6 -16 1999. The ASI was the fifteenth in a series held biannually on topics related to cooperative phenomena and phase transitions, in this case applied to soft condensed matter and its configurations, dynamics and functionality. It addressed the current experimental and theoretical knowledge of the physical properties of soft condensed matter such as polymers, gels, complex fluids, colloids, granular materials and biomaterials. The main purpose of the lectures was to obtain basic understanding of important aspects in relating molecular configurations and dynamics to macroscopic properties and biological functionality. To our knowledge, the term Soft Condensed Matter was actually coined and used for the first time in 1989 at Geilo and some selected topics of soft matter were also given at Geilo in 1991, 1993 and 1995. A return to this subject 10 years after its instigation thus allowed a fresh look and a possibility for defining new directions for research.

This volume comprises the proceedings of a NATO Advanced Study In stitute held at Geilo, Norway, April 6 -16 1999. The ASI was the fifteenth in a series held biannually on topics related to cooperative phenomena and phase transitions, in this case applied to soft condensed matter and its configurations, dynamics and functionality. It addressed the current experimental and theoretical knowledge of the physical properties of soft condensed matter such as polymers, gels, complex fluids, colloids, granular materials and biomaterials. The main purpose of the lectures was to obtain basic understanding of important aspects in relating molecular configurations and dynamics to macroscopic properties and biological functionality. To our knowledge, the term Soft Condensed Matter was actually coined and used for the first time in 1989 at Geilo and some selected topics of soft matter were also given at Geilo in 1991, 1993 and 1995. A return to this subject 10 years after its instigation thus allowed a fresh look and a possibility for defining new directions for research."

Magnetism encompasses a wide range of systems and physical phenomena, and its study has posed and exposed both important fundamental problems and many practical applications. Recently, several entirely new phenomena have thus been discovered, generated through cooperative behaviour which could not have been predicted from a knowledge of one-spin' states. At the same time, advances in sample preparation, experimental technique, apparatus and radiation sources, have led to increasing precision in the investigation and exposure of greater subtleties in magnetic thin films, multilayers and other systems. Examples of unexpected and conceptually new phenomena occur in strongly correlated and fluctuating quantum systems, producing effects such as Haldane and spin-Peierls gaps, solitons, quantum spin glasses and spin liquids. The discovery and elucidation of these emerging properties' is a central theme in modern condensed matter physics. The present book comprises a series of chapters by world experts, covering both theoretical and experimental aspects. The approach is pedagogical and tutorial, but fully up to date, covering the latest research. The level is appropriate to graduate researchers who may either be just moving into the field or who are already active in condensed matter physics.

Many mesoscopic systems display adaptive' behaviour - changes in some physical property that results from a small change in an internal or external driving force. There is a kind of progression in adaptive phenomena, from quantum mesoscopics to complex, evolved cooperative systems and large scale events like turbulence. The field of mesoscopic magnetism, especially quantum coherence and quantum tunnelling in spin systems, and the coupling between mesoscopic magnetism and mesoscopic transport is currently a very active area of solid state physics. Dephasing' is an important concept in mesoscopic systems like these. A basic question is the limit at which quantum mechanics breaks down and what it can be replaced with. Another interesting crossover is that between complexity and large excursions or events, with turbulence as a prototype example. The book also contains a discussion of finance. Qualitatively speaking, turbulence and financial markets are apparently similar, so our understanding of turbulence may be relevant to understanding price fluctuations.