New Topics In Josephson Junction And Superconductivity Research

The Josephson Junction is a type of electronic circuit capable of switching at very high speeds when operated at temperatures approaching absolute zero. It exploits the phenomenon of superconductivity, the ability of certain materials to conduct electric current with practically zero resistance. This book presents new and important research in superconductivity. This includes optical properties, magneto-optics and surface acoustic waves, microwave responses, theories of superconductivity, synthesis in electronic applications and high temperature superconductivity.

A Josephson Junction is a type of electronic circuit capable of switching at very high speeds when operated at temperatures approaching absolute zero. The Josephson Junction exploits the phenomenon of superconductivity, the ability of certain materials to conduct electric current with practically zero resistance. This book presents new and important research in superconductivity. This book presents leading research from around the world in this exciting field. This includes fabrication techniques, unconventional superconductors, Josephson tunnel junctions, Josephson vortex behaviour, thermomagnetic shock waves and finite temperature effects.

In this book new experimental investigations of properties of Josephson junctions and systems are explored with the help of recent developments in superconductivity. The theory of the Josephson effect is presented taking into account the influence of multiband and anisotropy effects in new superconducting compounds. Anharmonicity effects in current-phase relation on Josephson junctions dynamics are discussed. Recent studies in analogue and digital superconductivity electronics are presented. Topics of special interest include resistive single flux quantum logic in digital electronics. Application of Josephson junctions in quantum computing as superconducting quantum bits are analyzed. Particular attention is given to understanding chaotic behaviour of Josephson junctions and systems. The book is written for graduate students and researchers in the field of applied superconductivity.

Superconductivity is the ability of certain materials to conduct electrical current with no resistance and extremely low losses. High temperature superconductors, such as La2-xSrxCuOx (Tc=40K) and YBa2Cu3O7-x (Tc=90K), were discovered in 1987 and have been actively studied since. In spite of an intense, world-wide, research effort during this time, a complete understanding of the copper oxide (cuprate) materials is still lacking. Many fundamental questions are unanswered, particularly the mechanism by which high-Tc superconductivity occurs. More broadly, the cuprates are in a class of solids with strong electron-electron interactions. An understanding of such "strongly correlated" solids is perhaps the major unsolved problem of condensed matter physics with over ten thousand researchers working on this topic. High-Tc superconductors also 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 volume brings together new leading-edge research in the field.

This book provides a comprehensive and up-to-date description of the Josephson effect, a topic of never-ending interest in both fundamental and applied physics. In this volume, world-renowned experts present the unique aspects of the physics of the Josephson effect, resulting from the use of new materials, of hybrid architectures and from the possibility of realizing nanoscale junctions. These new experimental capabilities lead to systems where novel coherent phenomena and transport processes emerge. All this is of great relevance and impact, especially when combined with the didactic approach of the book. The reader will benefit from a general and modern view of coherent phenomena in weakly-coupled superconductors on a macroscopic scale. Topics that have been only recently discussed in specialized papers and in short reviews are described here for the first time and organized in a general framework. An important section of the book is also devoted to applications, with focus on long-term, future applications. In addition to a significant number of illustrations, the book includes numerous tables for comparative studies on technical aspects.

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.

Superconductivity is a phenomenon occurring in certain materials at extremely low temperatures, characterized by exactly zero electrical resistance and the exclusion of the interior magnetic field (the Meissner effect). The electrical resistivity of a metallic conductor decreases gradually as the temperature is lowered. However, in ordinary conductors such as copper and silver, impurities and other defects impose a lower limit. Even near absolute zero a real sample of copper shows a non-zero resistance. The resistance of a superconductor, on the other hand, drops abruptly to zero when the material is cooled below its "critical temperature", typically 20 kelvin or less. An electrical current flowing in a loop of superconducting wire can persist indefinitely with no power source. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It cannot be understood simply as the idealisation of "perfect conductivity" in classical physics. Superconductivity occurs in a wide variety of materials, including simple elements like tin and aluminium, various metallic alloys and some heavily-doped semiconductors. Superconductivity does not occur in noble metals like gold and silver, nor in most ferromagnetic metals. In 1986 the discovery of a family of cuprate-perovskite ceramic materials known as high-temperature superconductors, with critical temperatures in excess of 90 kelvin, spurred renewed interest and research in superconductivity for several reasons. As a topic of pure research, these materials represented a new phenomenon not explained by the current theory. And, because the superconducting state persists up to more manageable temperatures, more commercial applications are feasible, especially if materials with even higher critical temperatures could be discovered. This new book presents leading research from around the world in this dynamic field.

The Advanced Study Institute on "Advances in Superconductivity" was held at the Ettore Majorana Centre for Scientific Culture in Erice, Sicily, during July 3 to July 15, 1982. This Institute was the third course of the International School of Low Tempera ture Physics, which was established at the Centre in 1977 with the guidance and inspiration of T. Regge and A. Zichichi. The 1982 Course was centered on a topic which brought together fundamental basic research and the most recent promising technological applications. Accordingly, the participants represented a wide spectrum of industrial and government laboratories, as well as universities from various countries. The program of topics and speakers was developed with the advice of the Organizing Committee, composed of H. Frohlich, T. Regge, B. Stritzker, and L. Testardi. This Institute emphasized recent developments in the science and technology of superconductivity. A historical perspective was provided by H. Frohlich, whose lectures recall the earliest discoveries and theoretical attempts to understand superconductivity. Ironically, his early suggestion of the electron-phonon coupling as a key to superconductivity was met with initial widespread skepticism. Later, the development of field theory methods for solid state physics problems, and the evolution of the BCS theory has led to a seemingly unanimous concensus regarding the e1ectron phonon mechanism as the predominant source of superconductivity in known materials. Experimental studies of superconductivity exemplify the strong interplay of science and technology in many ways.