Nonequilibrium Superconductivity Phonons And Kapitza Boundaries

The importance of phonons has long been recognized by research ers in nonequilibrium superconductivity. Similarly, experimentalists studying phonons at low temperatures have relied heavily on supercon ductors as sources and detectors. To a large extent this symbiotic relationship has developed with a general mutual awareness; however, to our knowledge these subjects have never been treated together in conferences or study institutes. It was with the hope of further contributing to the awareness and communication between workers in these areas that this NATO Advanced Study Institute (ASI) has been conceived. A second, but equally important, reason for holding this ASI is to fill a void by providing the first general textbook in this important area of physics. Therefore, there was an emphasis on the tutorial nature of the lectures and written contributions to this textbook. It should not go unnoticed that the experimental and theoretical concepts covered in this textbook are of paramount importance to the various applications of superconductors. Almost by definition, the use of a superconductor implies a nonequilibrium state! For example, phonon conduction to the helium bath is important in devices ranging from microscopic Josephson junctions to large scale magnets and transmission lines. Knowledge of the more fundamental nonequilibrium effects can aid in our understanding of devices as well as provide the potential for entirely new applications.

This book introduces the main concepts of nonequilibrium phenomena in superconductors. The authors cover both experimentally well-understood topics and problems which physicists could challenge more in view of current theoretical understanding. Some of these topics include thermoelectric phenomena, influence of laser radiation as well as fluctuations in superconductors.

Phonons are always present in the solid state even at an absolute temperature of 0 K where zero point vibrations still abound. Moreover, phonons interact with all other excitations of the solid state and, thereby, influence most of its properties. Historically experimental information on phonon transport came from measurements of thermal conductivity. Over the past two decades much more, and much more detailed, information on phonon transport and on many of the inherent phonon interaction processes have come to light from experiments which use nonequilibrium phonons to study their dynamics. The resultant research field has most recently blossomed with the development of ever more sophisticated experimental and theoretical methods which can be applied to it. In fact, the field is moving so rapidly that new members of the research community have difficulties in keeping up to date. This NATO Advanced Study Institute (ASI) was organized with the objective of overcoming the information barrier between those expert in the field and those who are new to it. Thus it was decided to (i) organize a set of tutorially based lectures covering most of the important facets in the field, and (ii) to produce an Institute proceedings which would serve both as the first general textbook, as well as a valuable reference book, for this field of knowledge.

Starting from the early experiments, this detailed presentation, containing more than 500 references, provides a comprehensive review on current-induced nonequilibrium phenomena in quasi-one-dimensional superconductors, leading the reader from the fundamentals to the most recent research results. Experiments on monocrystalline filaments (whiskers) - including those obtained by the author - are compared with results on long thin film microbridges and related species and interpreted within the theoretical framework. Instructions on experimental techniques are given and yet unresolved problems are discussed. The book is well suited as an introduction for the novice and as a handbook for the active researcher.

This workshop is a series of meetings organized by the Institute for Scientific Interchange in Torino, Italy. It focuses on the potential of Superconductivity in the field of radiation detection and is particularly timely and important. The proceedings of the workshop highlights research on Superconducting Detectors for Nuclear Physics, Particle Physics and Astrophysics, Superconducting Tunneling Junctions, Superheated Superconducting Granules among other topics.

Superconducting Devices presents the theory, qualification, and fabrication of superconducting device elements and integrated circuitry. This book discusses the various uses of superconducting devices in many areas where their sensitivity, speed, or other characteristics stemming from the unique nature of superconductivity make them the device of choice. Organized into 10 chapters, this book begins with an overview of superconducting quantum interference devices (SQUIDs), which is the main achievement of superconductor electronics. This text then examines the status of dc and rf SQUIDs. Other chapters consider the progress in the fabrication technology for high-quality junctions and it integration technology, which are developed mainly for digital applications. This book discusses as well the increasing need for compact submillimeter sources for use in such applications as satellite communications and receivers for astronomical observation. The final chapter deals with the thin film tunneling experiments. This book is a valuable resource for physicists, chemists, materials scientists, and electrical engineers.