The Gap Symmetry and Fluctuations in High-Tc Superconductors

Since the discovery in 1986 of high temperature superconductors by J. G. Bednorz and K. A. Müller, a considerable progress has been made and several important scientific problems have emerged. Within this NATO Advanced Study Institute our intention was to focus mainly on the controversial topic of the symmetry of the superconducting gap and given the very short coherence length, the role of fluctuations. The Institute on 'The Gap Symmetry and Fluctuations in High- Superconductors' took place in the "Institut d'Etudes Scientifiques de Cargèse" in Corsica, France, between 1 - 13 September 1997. The 110 participantsfrom 18 countries (yet 30 nationalities) including 23 full time lecturers, have spent two memorable weeks in this charming Mediterranean resort. All lecturers were asked to prepare pedagogical papers to clearly present the central physical idea behind specific model or experiment. The better understanding of physics of high temperature superconductivity is certainly needed to guide the development of applications of these materials in high and weak current devices.

to High Temperature Superconducting Oxides.- Status of High Tc.- Theories and Models.- Superconductivity in Cuprates, The Van Hove Scenario: A Review.- High Tc Oxides: Two Order Parameters, Magnetic Scattering and Upper Limit of Tc, Novel Isotope Effects, and the Phonon-Plasmon Mechanism.- Mott Metal-Insulator Transition in Oxides.- Scaling Behavior of the Normal State Properties and the Superfluid Density in Metallic YBa2Cu3Ox Cuprates.- The Spin Fluctuation Model for High Temperature Superconductivity: Progress and Prospects.- A Theory of the Non-Fermi-Liquid Properties and Superconductivity in Copper-Oxides.- Materials and Applications.- Current Research Issues for the Electron-Doped Cuprates.- Superconductivity of Heavy-Electron Compounds - Comparison with Cuprates.- The Inhomogeneity of High-Tc Superconductors.- Applications of HTS to Space and Electronics.- Optical Spectroscopies.- Photoemission as a Probe of Superconductivity.- Electronic Structure and Doping in Cuprate Superconductors.- The Electronic Structure of the HighTc Superconductors Obtained by Angle-Resolved Photoemission.- Light Scattering from Charge and Spin Excitations in Cuprate Systems.- Analysis of the Superconducting Gap by Electronic Raman Scattering in HgBa2Ca2Cu3O8+? Single Crystals.- Magnetic Properties.- Evidence for Gap Asymmetry and Spin Fluctuations from Nuclear Magnetic Resonance (NMR).- NMR in the Normal State of Cuprates.- From Magnons to the Resonance Peak: Spin Dynamics in High-TC Superconducting Cuprates by Inelastic Neutron Scattering.- Thermodynamic Properties and Fluctuations.- Magnetic Penetration Depths in Cuprates: A short Review of Measurement Techniques and Results.- Specific Heat Experiments in High Magnetic Fields: D-Wave Symmetry, Fluctuations, Vortex Melting.- TheSpectrum of Thermodynamic Fluctuations in Short Coherence Length Superconductors.- Multilayering Effects on the Thermal Fluctuations of Cooper Pairs Around the Superconducting Transition in Cuprates.- C-Axis Conductivity and the Role of D-Wave Superconductivity and Fluctuations on Anisotropic High Temperature Superconductors.- Tunneling Experiments.- Scanning Tunneling Spectroscopy on High Temperature Superconductors.- From the Andreev Reflection to the Sharvin Contact Conductance.- Tunneling in High Tc Superconducting Cuprates.- Flux Quantization Experiments in Cuprate Superconductors.