The authors introduce the full content of the Microscopic Theory of Superfluid He II, developed since 1998; also given are brief accounts of the application of one concept from the theory, the QCE1 Superfluidity Mechanism, to superconductors. One peer review report writes: "The authors include more of the underlying physics than some earlier theories, and the comparisons they make with experimental data are satisfactory". The Microscopic Theory of Superfluid He II has several important features, which distinguishes this theory from the previous theories of He II. The immense volume of information the authors have today, especially the pieces of information revealing the microscopic dynamics of the system, was not available to the developers of the previous theories in the 1930s-1940s. This book also demonstrates how the general principles of quantum mechanics and condensed matter physics can be consistently applied to a given system with confidence, once a realistic microscopic model is derived for it. It demonstrates in turn the validity of the general physics principles in such an extreme system as the quantum fluid He II.

High-Tc superconductors have significant potential for applications in technologies ranging from electric power generation and transmission to digital electronics. This ability to carry large amounts of current can be applied to electric power devices such as motors and generators, and to electricity transmission in power lines. For example, superconductors can carry as much as 100 times the amount of electricity of ordinary copper or aluminium wires of the same size. Many universities, research institutes and companies are working to develop high-Tc superconductivity applications and considerable progress has been made. This book presents leading research from around the world in this exciting field.

This book is based on lectures delivered at a meeting organised by the academia Nazionale dei Lincei with contributions from some of the leading research workers in the field. They deal with topics of contemporary interest such as: solitons, hydrodynamic and nonlinear problems in superfluids, turbulence, thermodynamics, first and second sound, and the comparison between superconductivity and superfluidity. Experimental results and theoretical considerations are included. Thus the book will be an invaluable survey for research workers in superfluidity.

Superfluidity and Superconductivity, Third Edition introduces the low-temperature phenomena of superfluidity and superconductivity from a unified viewpoint. The book stresses the existence of a macroscopic wave function as a central principle, presents an extensive discussion of macroscopic theories, and includes full descriptions of relevant experimental results throughout. This edition also features an additional chapter on high-temperature superconductors. With problems at the end of most chapters as well as the careful elaboration of basic principles, this comprehensive survey of experiment and theory provides an accessible and invaluable foundation for graduate students studying low-temperature physics as well as senior undergraduates taking specialized courses.

This book covers main properties of the excitation spectrum in superfluid 4He and the thermodynamics determined by the spectrum. It deals with hydrodynamics and describes that quantitative results should be insignificantly modified with processes of phonon decay taken into account.