Topological quantum numbers are distinguished from quantum numbers based on symmetry because they are insensitive to the imperfections of the systems in which they are observed. They have become very important in precision measurements in recent years, and provide the best measurements of voltage and electrical resistance. This book describes the theory of such quantum numbers, starting with Dirac's argument for the quantization of electric charge, and continuing with discussions on the helium superfluids, flux quantization and the Josephson effect in superconductors, the quantum Hall effect, solids and liquid crystals, and topological phase transitions. The accompanying reprints include some of the classic experimental and theoretical papers in this area.Physicists — both experimental and theoretical — who are interested in the topic will find this book an invaluable reference.

A wide range of progress in materials development [single crystals, ceramics, thin films, wire and tapes] is reported in the 169 papers in this volume. The main focus of the papers is in attaining a better understanding of the relationship between microstructure and electrical properties. Invited papers cover topics such as the effects of substitution and doping; multilayers; nanostructure characterisation; electric field effects in High Tc Superconductors [HTS]; surface stability; critical currents; flux pinning and magnetooptic imaging of flux patterns; effects of irradiation induced defects; properties and preparation of materials; microwave properties and electronic devices. A clearly broadened basis for understanding processes and mechanisms in [HTS] is portrayed. Appreciable progress has been achieved in the reproducible manufacturing of high quality materials supported by very efficient methods in microstructural analysis. This essential improvement is reflected in the increased number of practical devices encouraging the use of HTS in applications for electronics and power engineering, all of which are reviewed in depth in this work.

Unconventional superconductivity (or superconductivity with a nontrivial Cooper pairing) is believed to exist in many heavy-fermion materials as well as in high temperature superconductors, and is a subject of great theoretical and experimental interest. The remarkable progress achieved in this field has not been reflected in published monographs and textbooks, and there is a gap between current research and the standard education of solid state physicists in the theory of superconductivity. This book is intended to meet this information need and includes the authors' original results.