This book is intended for postgraduate students as well as researchers in various areas of physics such as statistical physics, magnetism and materials sciences. The content of the book covers mainly frustrated spin systems with possible applications in domains where physical systems can be mapped into the spin language. Pedagogical effort has been made to make each chapter to be self-contained, comprehensible for researchers who are not really involved in the field. Basic methods are given in detail.

Systems displaying competing interactions of some kind are widespread - much more, in fact, as commonly anticipated (magnetic and Ising-type interactions or the dynamics of DNA molecules being only two popular examples). Written for researchers in the field with different professional backgrounds, this volume classifies phenomena not by system but rather by the type of competing interactions involved. This allows for a straightforward presentation of the underlying principles and the universal laws governing the behaviour of different systems. Starting with a historical overview, the author proceeds by describing self-competitions of various types of interactions (such as diploar or multipolar interactions), competitions between a short-range and a long-range interaction (as in Ising systems or DNA models) or between a long-range interaction and an anisotropy (as in ultrathin magnetic films or magnetic nanoparticles) and finally competitions between interactions of the same range (as in spin glasses). Each chapter contains a few problems with solutions which provide suitable material for lecturers of mathematics and physics as well as biology courses. A vast body of references to the original literature make the volume self-contained and ideally suited to master this interdisciplinary field.

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.

Many macroscopic properties of materials are determined primarily by inhomogeneous structures and textures. These intermediate-scale structures often arise from competing interactions operating on different length scales within the material. Our understanding of such phenomena has increased substantially with the identification and theoretical description of solid-state materials with incommensurate and long-period modulated phases, such as ferroelectrics, charge-density-wave compounds, epitaxial layers and polytypes. Experimental diagnosis of inhomogeneous ground states and metastable phases has advanced so far that these are now well-accepted phenomena. These proceedings bring together the work of physicists and materials scientists to review developments in this area and to examine possible future directions, such as how the microscopic understanding emerging in bench-top solid-state systems can be applied in materials science.

An understanding of the quantum mechanical nature of magnetism has led to the development of new magnetic materials which are used as permanent magnets, sensors, and information storage. Behind these practical applications lie a range of fundamental ideas, including symmetry breaking, order parameters, excitations, frustration, and reduced dimensionality. This superb new textbook presents a logical account of these ideas, staring from basic concepts in electromagnetsim and quantum mechanics. It outlines the origin of magnetic moments in atoms and how these moments can be affected by their local environment inside a crystal. The different types of interactions which can be present between magnetic moments are described. The final chapters of the book are devoted to the magnetic properties of metals, and to the complex behaviour which can occur when competing magnetic interactions are present and/or the system has a reduced dimensionality. Throughout the text, the theorectical principles are applied to real systems. There is substantial discussion of experimental techniques and current reserach topics. The book is copiously illustrated and contains detailed appendices which cover the fundamental principles.

Modern Techniques for Characterizing Magnetic Materials provides an extensive overview of novel characterization tools for magnetic materials including neutron, photon and electron scatterings and other microscopy techniques by world-renowned scientists. This interdisciplinary reference describes all available techniques to characterize and to understand magnetic materials, techniques that cover a wide range of length scales and belong to different scientific communities. The diverse contributions enhance cross-discipline communication, while also identifying both the drawbacks and advantages of different techniques, which can result in deriving effective combinations of techniques that are especially fruitful at nanometer scales. It will be a valuable resource for all graduate students, researchers, engineers and scientists who are interested in magnetic materials including their crystal structure, electronic structure, magnetization dynamics and their associated magnetic properties and underlying magnetism.

In this thesis, novel Monte Carlo methods for precisely calculating the critical phenomena of the effectively frustrated quantum spin system are developed and applied to the critical phenomena of the spin-Peierls systems. Three significant methods are introduced for the first time: a new optimization algorithm of the Markov chain transition kernel based on the geometric weight-allocation approach, the extension of the worm (directed-loop) algorithm to nonconserved particles, and the combination with the level spectroscopy. Utilizing these methods, the phase diagram of the one-dimensional XXZ spin-Peierls system is elucidated. Furthermore, the multi-chain and two-dimensional spin-Peierls systems with interchain lattice interaction are investigated. The unbiased simulation shows that the interesting quantum phase transition between the 1D-like liquid phase and the macroscopically-degenerated dimer phase occurs on the fully-frustrated parameter line that separates the doubly-degenerated dimer phases in the two-dimensional phase diagram. The spin-phonon interaction in the spin-Peierls system introduces the spin frustration, which usually hinders the quantum Monte Carlo analysis, owing to the notorious negative sign problem. In this thesis, the author has succeeded in precisely calculating the critical phenomena of the effectively frustrated quantum spin system by means of the quantum Monte Carlo method without the negative sign.

This book covers all principal aspects of currently investigated frustrated systems, from exactly solved frustrated models to real experimental frustrated systems, going through renormalization group treatment, Monte Carlo investigation of frustrated classical Ising and vector spin models, low-dimensional systems, spin ice and quantum spin glass. The reader can OCo within a single book OCo obtain a global view of the current research development in the field of frustrated systems.This new edition is updated with recent theoretical, numerical and experimental developments in the field of frustrated spin systems. The first edition of the book appeared in 2005. In this edition, more recent works until 2012 are reviewed. It contains nine chapters written by researchers who have actively contributed to the field. Many results are from recent works of the authors.The book is intended for postgraduate students as well as researchers in statistical physics, magnetism, materials science and various domains where real systems can be described with the spin language. Explicit demonstrations of formulas and full arguments leading to important results are given where it is possible to do so."

Neutron spin echo (NSE) spectroscopy is the highest energy resolution neutron scattering technique available for examining a large area (in time and space) in condensed matter physics. This broad dynamic and spatial range is extensively exploited in the study of a wide range of scientific problems ranging from the dynamics of glasses, polymer melts, complex fluids and microemulsions to the elementary excitations in superfluid 4He and to ferromagnets and spin glasses. This book reviews the current status and future prospects in NSE spectroscopy describing the method, latest instrumentation and also the use of NSE in fundamental, hard- and soft-matter science. It provides first-hand information for researchers working in the fields touched by NSE. In addition, young researchers, PhD students and graduates interested in the method will obtain a comprehensive overview and guidelines to implementing the NSE technique.

The last few years have seen many developments in the study of ?frustrated? systems, such as spin glasses and random fields. In addition, the application of the idea of spin glasses to other branches of physics, such as vortex lines in high temperature superconductors, protein folding, structural glasses, and the vulcanization of rubber, has been flourishing. The earlier reviews are several years old, so now is an appropriate time to summarize the recent developments. The articles in this book have been written by leading researchers and include theoretical and experimental studies, and large-scale numerical work (using state-of-the-art algorithms designed specifically for spin-glass-type problems), as well as analytical studies.