Dynamics of Magnetic Fluctuations in High-Temperature Superconductors

ISBN-13: 9781468474923 / Angielski / Miękka / 2012 / 368 str.

George Reiter; Peter Horsch;Gregory C. Psaltakis

Opis

This NATO Advanced Research Workshop was held at a time when there was little consensus as to the mechanism for high temperature superconductivity, in the context of a world undergoing major changes in its political alignments and sense of the possibility for the future. It was characterized by generosity in the sharing of our uncertainties and speculations, as was appropriate for both the subject matter and the context. The workshop was organized, of necessity around the experimental work, as is this volume. Where the theoretical work is directly relevant to particular experiments, it is included in the appropriate sections with them. Most of the participants felt strongly that magnetic fluctuations played an important role in the mechanism for high T c, although with the exception of the IlS R work reported by Luke showing results inconsistent with the anyon picture, and the work on flux phases by Lederer, the mechanism remained an issue in the background. A major focus was the phenomenological interpretation of the NMR data.

Spis treści

A. Neutron Scattering.- Antiferromagnetic Spin Fluctuations in Cuprate Superconductors.- Neutron Scattering Measurements of the Magnetic Excitations of High-Temperature Superconducting Materials.- Neutron Scattering Study of the Spin Dynamics in YBa2Cu3O6+x.- Disordered Low Energy Component of the Magnetic Response in Both Antiferromagnetic and Superconducting Y-Ba-Cu-O Samples.- B. NMR.- Copper and Oxygen NMR Studies On The Magnetic Properties of YBa2CuO7-y.- 17O and 63Cu NMR Investigation of Spin Fluctuations in High Tc Superconducting Oxides.- Local Hyperfine Interactions of Delocalized Electron Spins: 205TI Investigations in Tl Containing High Tc Superconductors.- Weak Coupling Analysis of Spin Fluctuations In Layered Cuprates.- Influence of the Antiferromagnetic Fluctuations On The Nuclear Magnetic Resonance In The Cu-O High Temperature Superconductors.- Microscopic Models for Spin Dynamics in the CuO2 Planes with Application to NMR.- C. µSR.- Recent Topics OF µSR Studies Of High-Tc Systems.- Recent Results In The Application Of µSR To The Study Of Magnetic Properties Of High-Tc Oxides.- On the phase diagram of bismuth based Superconductors.- D. Raman Scattering.- Raman scattering from spin fluctuations in cuprates.- E. Photoemission.- Electronic structure of Bi2Sr2CaCu2O8 single crystals at the fermi level.- Calculation of the photoemission spectra for the t-J model and the extended hubbard model.- F. Macroscopic Fluctuations.- Microwave absorbtion of superconductors in low magnetic fields.- Magnetic properties of a granular superconductor.- G. Transport Properties.- Thermodynamic fluctuations and their dimensionality in ceramic superconductors out of transport properties measurements.- H. General Theory.- Models Of High Temperature Superconductors.- BSC Theory Extended To Anisotropic And Layered High-Temperature Superconductors.- Correlated Electron Motion, Flux States And Superconductivity.- Orbital Dynamics And Spin Fluctuations In Cuprates.- Magnetic Frustration Model And Superconductivity On Doped Lamellar CuO2 Systems.- I. One Band Hubbard Models.- Strong Coupling Regime In The Hubbard Model At Low Densities.- How Good Is The Strong Coupling Expansion Of The Two Dimensional Hubbard Model.- The Hubbard Model For n ? 1.0: New Preliminary Results.- J. Heisenberg Model Dynamics.- Exact Microscopic Calculation Of Spin Wave Frequencies And Linewidths In The Two Dimensional Heisenberg Antiferromagnet At Low Temperature.- Magnetic Excitations In The Disordered Phase Of The 2-D Heisenberg Antiferromagnet.- K. Quasiparticles and Magnetic Fluctuations.- Exact Diagonalization Studies Of Quasiparticles In Doped Quantum Antiferromagnets.- Copper Spin Correlations Induced By Oxygen Hole Motion.- Spin Polarons In The t-J Model.- Analytic Evaluation Of The 1-Hole Spectral Function For The 1-D t-J Model In The Limit J ?.- Doping Effects On The Spin-Density-Wave Background.- L. Magnetic phases.- Phase Separation In A t-J Model.- Spiral Magnetic Phases As A Result Of Doping In High Tc Compounds.