Strong Correlation And Superconductivity

This volume contains the proceedings of the ffiM Japan International Sympo sium on Strong Correlation and Superconductivity, which was held in Keidan ren Guest House at the foot of Mt. Fuji, May 21-25, 1989. The purpose of the Symposium was to provide an opportunity for discus sions on the problem of strong correlation of electrons in the context of high-Tc superconductivity. Sixty-eight scientists were invited from seven countries and forty-three papers were presented in the Symposium. Soon after the discovery ofhigh-Tc superconducting oxides, Professor P. W. Anderson proposed that the essence of high-Tc superconductivity lies in the strong correlation among the electrons in these materials. This proposal has stimulated a wide range of theoretical investigations on this profound and dif ficult problem, which are expected to lead eventually to new concepts describ ing strong electron correlation. In the Symposium, Anderson himself started lively discussions by his talk entitled "Myth and Reality in High-Tc Supercon ductivity", which was followed by various reports on theoretical studies and experimental results. Concise and thoughtful summaries of experiment and theory were given by Professors H. R. Ott and P. A. Lee, respectively. It is our hope that this volume reflects the present status of the research activity on this outstanding problem from the viewpoint of the basic physics and that it will further stimulate the effort to understand these fascinating systems, the high-Tc oxides.

This book deals with the study of superconductivity in systems with coexisting wide and narrow bands. It has been previously suggested that superconductivity can be enhanced in systems with coexisting wide and narrow bands when the Fermi level is near the narrow band edge. In this book, the authors study two problems concerning this mechanism in order to: (a) provide a systematic understanding of the role of strong electron correlation effects, and (b) propose a realistic candidate material which meets the ideal criteria for high-Tc superconductivity. Regarding the role of strong correlation effects, the FLEX+DMFT method is adopted. Based on systematic calculations, the pairing mechanism is found to be indeed valid even when the strong correlation effect is considered within the formalism. In the second half of the book, the authors propose a feasible candidate material by introducing the concept of the “hidden ladder” electronic structure, arising from the combination of the bilayer lattice structure and the anisotropic orbitals of the electrons. As such, the book contributes a valuable theoretical guiding principle for seeking unknown high-Tc superconductors.

Contents:The First Five Years of High-Tc Superconductivity (K A Müller)Different Factors which Govern the Optimisation of High-Tc Superconductive Cuprates Involving Bi-, Tl or Pb (B Raveau, M Hervieu, C Michel, J Provost, A Maignan, C Simon & D Groult)Superconductivity in Cuprates and Other Oxides (H R Ott)Organic Superconductors with Tc Higher than 10K (T Ishiguro & Y Nogami)Fundamentals of RVB Theory and Some Applications to High Temperature Superconductors (G Baskaran)Anyons and Superconductivity (S Das Sarma)Mott Transition in the Hubbard Model (B S Shastry)Superconducting Pairing in Layered Superconductors (S S Jha)Breaking the Log-Jam in Many-Body Physics: Fermi Surfaces Without Fermi Liquids (P W Anderson)Superconductivity in High Magnetic Fields from a Microscopic Theory (A K Rajagopal)Nonequilibrium Superconductivity (R Tidecks)Neutron Scattering Study of the High-Tc Superconducting System YBa2Cu3O6+x (J Rossat-Mignod et al.)Crystal-Field Excitations in High-Tc Superconducting Materials (A Furrer)Superconducting Granular Films (S-I Kobayashi)Transport Properties in the Mixed State of High Temperature Superconductors (A Freimuth)Physics of Josephson Effect and Recent Advances (A Barone & S Pagano)Tunneling Spectroscopy of Copper Oxide Superconductors (T Ekino & J Akimitsu)Superconductivity and Magnetism in Heavy-Fermion Compounds (F Steglich, U Ahlheim, C D Bredl, C Geibel, M Lang, A Loidl & G Sparn)Nuclear Magnetic Resonance Studies in Highly Correlated Systems: Heavy Fermion and High-Tc Superconductors (K Asayama)Pulsed Laser and Cylindrical Magnetron Sputter Deposition of Epitaxial Metal Oxide Thin Films (T Venkatesan et al.) Readership: Physicists, chemists and engineers. keywords:

This is the second volume of a comprehensive two-volume treatise on superconductivity that represents the first such publication since the earlier widely acclaimed books by R. Parks. It systematically reviews the basic physics and recent advances in the field. Leading researchers describe the state of the art in conventional phonon-induced superconductivity, high-Tc superconductivity, and in novel superconductivity, including triplet pairing in the ruthenates. The second volume is largely concerned with novel superconductors, such as heavy-fermion metals and organic materials, and also includes granular superconductors. Important new results on current problems are presented in a manner designed to stimulate further research. Numerous illustrations, diagrams and tables make this book especially useful as a reference work for students, teachers and researchers. Volume 1 treats Conventional and High-Tc Superconductors (3-540-43883-1).

"High-Tc Superconductivity" is based on a meeting held in Kiev and contains contributions discussing the most recent achievements in this field. The book includes reviews and original papers covering theoretical and experimental aspects of the subject. Keywords: electronic and magnetic properties, metallization processes, emission and optic spectra, lavitation, pinning, frustration and fluctuations, thin films

Despite ten years of intensive research, many questions remain unanswered concerning the nature of the electronic structure (Fermi vs non-Fermi liquid) and mechanisms of superconductivity. Spectroscopy of High-Tc Superconductors, A Theoretical View provides a current, comprehensive review of the experimental results and theoretical interpre

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.

This book originated from a course given at the Univcrsidad Aut6noma of Madrid in the Spring of 1994 and in the Universidad Complutense of Madrid in 1995. The goal of these courses is to give the non-specialist an introduction to some old and new ideas in the field of strongly correlated systems, in particular the problems posed by the high-1~ superconducting materials. As theoretical physicists, our starting viewpoint to address the problem of strongly correlat ed ferlnion systems and related issues of modern condensed matter physics ·is the renormalization group approach applied both to quantU111 field theory and statistical physics. In recent years this has become not only a powerful tool for retrieving the essential physics of interacting systems but also a link between theoretical physics and modern condensed matter physics. Furthermore, once we have this common background for dealing with apparently different prob lems, we discuss more specific topics and even phenomenological aspects of the field. In doing so we have tried to make the exposition clear and simple, with out entering into technical details but focusing ill the fundamental physics of the phenomena under study. Therefore ,ve expect that our experience ll1ay have some value to other people entering this fascinating field. We have divided these notes into three parts and each part into chapters, which correspond roughly to one or two lectures. Part I, Chaps. 1-2 (A. H. V.