Novel Superconductivity

ISBN-13: 9781461290766 / Angielski / Miękka / 2011 / 1134 str.

Stuart A. Wolf; Vladimir Z. Kresin

Opis

The Novel Mechanisms of Superconductivity Conference was initially conceived in the early part of 1986 as a small, 2-1/2 day workshop of 40-70 scientists, both theorists and experimentalists interested in exploring the possible evidence for exotic, non phononic superconductivity. Of course, the historic discoveries of high temperature oxide superconductors by Bednorz and Mftller and the subsequent enhancements by the Houston/Alabama groups made such a small conference impractical. The conference necessarily had to expand, 2-1/2 days became 4-1/2 days and superconductivity in the high Tc oxides became the largest single topic in the workshop. In fact, this conference became the first major conference on this topic and thus, these proceedings are also the first maj or publication. However, heavy fermion, organic and low carrier concentration superconductors remained a very important part of this workshop and articles by the leaders in these fields are included in these proceedings. Ultimately the workshop hosted rearly 400 scientists, students and media including representatives from the maj or research groups in the U.S., Europe, Japan and the Soviet Union.

Spis treści

The Rocky Road to High Temperature Superconductivity.- I. Conventional Systems.- Electric Field Modulation of Low Electron Density Thin Film Superconductors.- Superconductivity at Contact of Ultrathin Gold Films with Amorphous Germanium.- Superconductivity in Thin Films of Au/Si by Ion Implantation.- Test of the Tc-Predictions Using the Rigid Band Model for Refractory Compounds.- Superconductivity and Metal Clusters.- Proximity Effect and Anderson Localization.- Superconductivity and Disorder in Low Carrier Density La-S.- Bounds on Superconducting Properties in Eliashberg Theory.- Disorder-Induced Pair Breaking in Superconductors.- Flux Lattice Melting in Amorphous Composite In/InOx Thin Film Superconductors.- Evidence for Non-Phonic Superconductivity in Nb3Ge.- II. Organic Superconductors.- One-Dimensional Correlations in Organic Superconductors: Magnetism and Superconductivity.- Anisotropic Superconductivity and NMR Relaxation Rate in Organic Superconductors.- Nuclear Magnetic Relaxation in the Organic Superconductor (TMTSF)2ClO4.- Electronic Band Structure and Point-Contact Spectroscopy of the Organic Superconductor ?-(BEDT-TTF)2I3.- The Origin of Pairing Interaction in Organic Superconductors.- Synthesis and Structure, Properties of BEDT-TTF Derivatives.- On the Possibility of High-Temperature Superconductivity in Organic Materials.- III. Heavy Fermions.- Heavy Electron Superconductivity.- Heavy Electron Superconductivity: From 1K to 90K to ?.- Critical Fields of UBe13 Films.- Kondo Lattices: Possible Mechanism for a Non-Phonon Superconductivity and Magnetic-Field-Induced Superconductivity.- Heavy Fermion Properties and their Relation to Electron Band Theory.- Ultrasonic Invatigation of Novel Superconducting Systems.- Phenomenology of Superconductivity and Magnetic Order in Heavy Fermi Liquids and Narrow-Band Metals.- Proximity Effects Between Conventional and Unconventional Superconductors.- Charge Imbalance Relaxation as a Probe of Anisotropic Heavy Fermion Superconductors.- Effects of Mass Enchantment on Cooper Pairing in Heavy-Fermion Superconductors.- IV. High Tc Oxides: General Properties.- Parameters, Exotic Properties of High Tc Superconductors.- The Ginzburg Criterion in the High Tc Oxides.- V. Theories of High Tc.- RVB Theory of High Tc Superconductivity.- Electronic Fluctuation, Pairing.- Non-Phonon Mechanisms of Superconductivity in High Tc Superconducting Oxides and Other Materials and their Manifestation.- Interactions and Interfaces in Layered Systems.- Excitonic Superconductivity in Layer Structures.- The Exciton Interaction: Its Possible Role in High Temperature Superconductivity.- Charge Transfer Resonances and Superconductive Pairing in the New Oxide Metals.- Bonds, Bands, Charge Transfer Excitations and Superconductivity: YBa2Cu3O7-? vs. YBa2Cu3O6.- Possible Role of Oxygen Vacancies, Excitonic Mechanism in High Tc Superconducting Oxides.- An Excitonic Model for the New High Temperature Superconductors.- Excitonic Theory of High Temperature Oxide Superconductors.- Superexchange Mediated Superconductivity in the Single Band Hubbard Model.- On Spin-Density Wave State in (La1-xMx)2 CuO4-?.- Critical Temperature of Superconductivty Caused by Strong Correlations.- Superconducting Energy Gap and Pairing Interaction in High Tc Oxides.- Are Spin Density Waves Involved in High Temperature Superconductivity?.- The Effect of Structural and Antiferromagnetic Phase Transitions on Superconductivity.- Effects of Coulomb Interaction on Superconductivity.- The Importance of Different Two Dimensional Plasmon Branches for High Tc Superconductors.- Basis and Consequences of the Two-Band Model for High Tc Oxide Superconductors.- Spectra of Plamons in Superconducting Cuprates.- The Role of Spatial Separation in Pairing Induced by Electronic Modes.- Elementary Remarks on High Temperature Superconductors.- Polaron Effects in High Tc Perovskite Superconductors.- Superconductivity Due to Negative-U Impurities.- Prediction of Anisotropic Thermopower of La2-xMxCuO4.- Band Structure, Electron-Phonon Interaction Calculations for Proposed High-Tc Superconducting Oxides: MCuO3 (M = La, Ba, Cs, Y) in the Perovskite Structure.- Character of States Near the Fermi Level in YBa2Cu3O7.- Elementary Theories of the Properties of the Cuprates.- Mean Field Approach to Double-Occupancy Induced Pairing in Oxide Superconductors.- Theoretical Model for Oxygen Vacancy Dependence of Tcin the YBa2Cu3Ox System (6 ? x ? 8).- Complex Hamiltonians: Common Features of Mechanisms for High-Tc and Slow Relaxation.- Superconductivity Due to Localized Bipolarons in Metal-Oxide Compounds.- Dilute Fermi Liquid of Heavy Polarons in Copper Oxide Superconductors.- Molecular Orbital Basis for Superconductivity with Applications to High-Tc Materials.- Supression of High Temperature Superconductivty by Disorder in the Resonant Valence Bond Model.- VI. Research on High Tc Superconductivity.- Discovery and Physics of Superconductivity Above 90K.- Mixed Valence Copper Oxides, High Tc Superconductors: Structural Study and Electron Transport Properties.- Tunneling Spectroscopy of Novel Superconductors.- Thermodynamic Critical Field of Y1Ba2Cu3O7.- Microstructure and Superconductivty in High Tc Materials.- Copper Oxidation States, Vacancy Ordering, Their Effect on High Temperature Superconductivty.- Bulk Superconductivity at 60K in Oxygen-Deficient Ba2YCu3O7-? and Oxygen Isotope Effect in La1.85Sr0.15CuO4.- Bulk Modulus Anomalies at the Superconducting Transitions of Single Phase YBa2Cu3O7 and La1.85Sr .15CuO4.- Absence of Resistivity Saturation, its Implications for the High Tc Superconductors.- EPR, Magnetization, Resistivity Studies in Doped (4f, 3d ions), Undoped R (or Y) Ba2Cu3O9-x High Tc Superconductors.- Upper Critical Field Measurements for RBa2Cu3O7 (R = Y, Eu.9Y.1, Sm).- Cu-O Superconductors: Through a Lens, but Darkly.- Single Crystal Superconducting Y1Ba2Cu3O7-? Oxide Films by Molecular Beam Epitaxy.- Chemical Doping and Physical Properties of the New High Temperature Superconducting Perovskites.- Properties of Oriented Oxide Superconductor Thin Films Prepared by Pulse Laser Evaporation from High-Tc Bulk Material.- Oxygen Isotope Effect in the High Temperature Superconductors YBa2Cu3O7-? and La1.85Sr0.15CuO4 with O 18 Substituted by Diffusion.- Magnetic Field Dependence of the Specific Heat of Some High-Tc Superconductors.- A Summary on Some Work on High Temperature Superconductors at Brookhaven National Laboratory.- A Neutron Powder Diffraction Study of Ba2YCu3O7.- Structural Phase Transformations and High Tc Superconductivity.- Neutron Scattering Studies of La2CuO4-?.- X-Ray Absorption Studies of La2-x(Ba,Sr)xCuO4 Superconductors.- Photoemission Studies of the High Tc Superconductor YBa2Cu3O9-?.- Muon Spin Relaxation Studies on High-Tc Superconductors.- Inductive Transition of YBa2Cu3O7-x in the 4 MHz Frequency Range.- Intrinsic Critical Current and Magnetization of YBa2Cu3O7.- The Effect of Anisotropy in Hc2 on the Breadth of the Resistive Transition of Polycrystalline YBa2Cu3O7-? in a Magnetic Field.- Superconducting Properties and Structural Characterization of High Tc Oxides.- The Variation of Tc with Hole Concentration in La2-xSrxCuO4-? Superconductors, Comparison with YBa2Cu3O7-?.- Anisotropy in Single-Crystal Y1Ba2Cu3O7-?.- Present Status of High Tc Oxide Superconductivty Studies at Tohoku University.- Current Carrying Properties in High Tc Y-Ba-Cu-O System.- Preparation, Structure and Magnetic Field Studies of High Tc Superconductors.- Magnetic Behavior of YBaCuO.- A Coupled Structure, Electrical Transition in La2Cu04 Near 30 K..- A Photoemission Study of High Tc Oxides.- Experiments on Heavy Electron and High Tc Oxide Superconductors.- Electronic States in High Tc Oxide Superconductors.- Flux-Quantum, Tunnel Characteristics of La2-xSrxCuO4 (x = 0.05 ? 0.2), MBa2Cu3O7 (M-Lu,Y) Ceramics.- Effect of Disordering on the Properties of High Temperature Ceramic Superconductors.- Anomalous Behavior of Elastic Characteristics YBa2Cu3O7 Near Tc.- Point Contact Study of Metal Oxide Superconductor Y-Ba-Cu-O.- Infared Reflectivity, Inelastic Light Scattering, Energy Gap in Y-Ba-Cu-O Superconductors.- Specific Features of Microwave Absorption of Superconducting Ceramics in a Magnetic Field.- Low Temperature X-Ray Analysis and Electron Microscopy of a New Family of Superconducting Materials.- Microwave Response of the Superconducting YBa2Cu3O9-x Ceramics.- Crystal Preparation of (La1-xMx)2CuO4 (M=Sr and Ba) and Discovery of Magnetic Superconductors Ln-Ba-Cu-O Systems (Ln=Lanthanide Atoms).- Optical-Reflectance Study of the Single-Crystal Superconductor (La1-xSrx)2CuO4.- Single X-ray Diffraction Study of (La1-xMx)2CuO4-? (M=Sr and Ba), La2CuO4-? and LnBa2Cu3O7-? (Ln=Y, Dy and Ho) Systems.- Single Crystal Studies, Electron Tunneling of (La1-xMx)2CuO4-? (M=Ba and Sr).- Study of Superconducting Oxides at Westinghouse.- Study of the Preparations and Properties of YBaCuO Films.- Some Physical Properties of High Temperature Superconductors.- Resistance Dependence, Thermogravimetric Analysis of the Er1Ba2 Cu3O9-? Superconductor Above Room Temperature.- Anomolous Resistive Behavior in Er1Ba2Cu3O9-? at 290 K.- Structure and the (014)/(005) X-ray Line Intensity in 1-2-3 Superconductors.- Measurement of Fluctuation-Enhanced Conductivity Above Tc in Y-Ba-Cu-O.- Grain Decoupling at Low Magnetic Fields in Ceramic YBa2Cu3O7-?.- Magnetization of Superconducting Ba(Y, Nd, Sm, Gd, Dy, Er, Yb) CuO Systems.- Josephson Effect, Energy Gap Measurements from Nb/YBCO Point Contact Structures.- Evidence of High Energy Excitations in High Tc Superconductors.- Structural, Charge-Transfer Description of High-Tc Superconductivity in Y1Ba2Cu3O7-?.- Tunneling Spectroscopy of High Tc Oxide Superconductors with a Scanning Tunneling Microscope.- Oxygen Ordering, Interfacial Superconductivity at Twin Boundaries in Landau-Ginzburg Superconductor Oxide Metal.- Superconductivty in YBa2-xSrxCu3O7-y and Y1-xSrxCuO3.- Cu Substitution into the La/Y Site in La1.8Sr.2CuO4, YBa2Cu3O7: Determination by X-ray Absorption Spectropscopy.- Hall Effect in YBa2Cu3O7-x vs Oxygen Content x: Observation of a Sharp Transition in RH vs. x.- Oxygen Stoichiomerty of YBa2Cu3O7-x.- Substitution for Copper in High-Tc Oxides.- Superconductivity in Pure La2CuO4.- Oxygen-Intercalation Effect upon Tetragonal-LaBa2Cu3-xOy Compound Samples.- Summary.- Trends and Future: Theory.- Trends and Future: As Seen at the Berkeley Workshop.- Concluding Remarks.- Participants.