This collection of recent results reports transport-property measurements on high-Tc superconductors and investigations by means of microwave conductivity, optical spectroscopy, high-energy spectroscopy, and nuclear magnetic resonance. Further contributions consider problems related to structure, doping, the electron-phonon interaction, electron correlation, and mechanisms of high-Tc superconductivity. Reviews providing introductions for nonspecialists to particular areas are followed by research reports detailing our current understanding.

This volume contains papers presented at the Thirteenth Taniguchi Symposium on the Theory of Condensed Matter, which was held at Kashikojima (in Ise Shima National Park), Japan, from 6th to 9th November, 1990. The topic of the symposium was Molecular Dynamics Simulations. The general objective of this series of the Taniguchi Symposia is to encour age developing fields of great promise in condensed matter physics. Our theme, molecular dynamics (MD) simulations, certainly fulfills this requirement, be cause the field is developing at a remarkable pace and its future is considered almost...

Advances through carefully conducted quantitative work on well designed, high quality materials characterize the present state of high-temperature superconductivity research. The contributions to this volume present a theoretical and experimental overview of electronic structure and physical properties, including anisotropic features, of high-temperative materials, with a focus on cuprates. In order to enhance the understanding of the mechanisms of superconductivity at high temperatures, this volume is divided into theoretical and experimental parts. The contributions to the two parts...

The motion of electrons in mesoscopic systems such as Aharonov-Bohm rings, small Josephson and tunnel junctions, quantum wires dots, and point contracts is presented in this volume in terms of a fully quantum mechanicaldescription of electronic states and current flows in solids. The comprehensive reviews by leading scientists in the field on the present understanding of mesoscopic systems will serve as a good basis for further development of the science and technology of quantum devices.

Owing to new physical, technological, and device concepts of low-dimensionalelectronic systems, the physics and fabrication of quasi-zero, one- and two-dimensional systems are rapidly growing fields. The contributions presented in this volume cover results of nanostructure fabrication including recently developed techniques, for example, tunneling probe techniques and molecular beam epitaxy, quantum transport including the integer and fractional quantum Hall effect, optical and transport studies of the two-dimensional Wigner solid, phonon studies of low-dimensional systems, and Si/SiGe...

At the present moment, after the success of the renormalization group in providing a conceptual framework for studying second-order phase tran sitions, we have a nearly satisfactory understanding of the statistical me chanics of classical systems with a non-random Hamiltonian. The situation is completely different if we consider the theory of systems with a random Hamiltonian or of chaotic dynamical systems. The two fields are connected; in fact, in the latter the effects of deterministic chaos can be modelled by an appropriate stochastic process. Although many interesting results have been...

Structural stability is of fundamental importance in materials science. Up-to-date information on the theoretical aspects of phase stability of materials is contained in this volume. Most of the first-principles calculations are based on the local-density approximation (LDA). In contrast, this volume contains very recent results of "going beyond LDA," such as the density gradient expansion and the quantum Monte-Carlomethod. Following the recently introduced theoretical methods for the calculation of interatomic potentials, forces acting on atoms and total energies such as the Car-Parrinello,...

Correlation Effects in Low-Dimensional Electron Systems describes recent developments in theoretical condensed-matter physics, emphasizing exact solutions in one dimension including conformal-field theoretical approaches, the application of quantum groups, and numerical diagonalization techniques. Various key properties are presented for two-dimensional, highly correlated electron systems.

The experimental discovery of the fractional quantum Hall effect (FQHE) at the end of 1981 by Tsui, Stormer and Gossard was absolutely unexpected since, at this time, no theoretical work existed that could predict new struc tures in the magnetotransport coefficients under conditions representing the extreme quantum limit. It is more than thirty years since investigations of bulk semiconductors in very strong magnetic fields were begun. Under these conditions, only the lowest Landau level is occupied and the theory predicted a monotonic variation of the resistivity with increasing magnetic...