Condensed-Matter physics

Condensed-Matter Physics 1
Copyright 2
Preface 7
Contents 11
I Highlights, Opportunities, and Needs 19
CONDENSED-MATTER PHYSICS AND ITS IMPORTANCE 21
DISCOVERY 24
Artificially Structured Materials 24
The Quantized Hall Effect 25
Effects of Reduced Dimensionality 26
Charge-Density Waves 26
Disorder 27
Mixed Valence and Heavy Fermions 28
The Superfluid Phases of 3He 28
The Renormalization Group Methods 29
Chaotic Phenomena in Time and Space 30
Widespread Use of Synchrotron Radiation 30
Atomic Resolution Experimental Probes 31
RESEARCH OPPORTUNITIES IN CONDENSED-MATTER PHYSICS IN THE NEXT DECADE 32
NEEDS OF CONDENSED-MATTER PHYSICS IN THE NEXT DECADE 37
Support for Individual Researchers 39
MANPOWER 39
INSTRUMENTATION 41
COMPUTATION 43
FUNDING 44
Support for National Facilities 45
NEUTRON FACILITIES 46
SYNCHROTRON RADIATION SOURCES RECOMMENDATIONS 47
HIGH-MAGNETIC-FIELD FACILITIES RECOMMENDATIONS 49
ELECTRON-MICROSCOPE FACILITIES RECOMMENDATIONS 49
GENERAL RECOMMENDATIONS CONCERNING NATIONAL FACILITIES 50
University-Industry-Government Relations 51
II A Decade of Condensed-Matter Physics 55
1 Electronic Structure and Properties of Matter 57
INTRODUCTION 57
ADVANCES IN ELECTRONIC STRUCTURE DETERMINATIONS 58
MANY-ELECTRON EFFECTS 59
QUANTIZED HALL EFFECT 60
ELECTRON-HOLE DROPLETS 63
ELECTRONICALLY ORDERED STATES 63
DISORDERED SYSTEMS 65
MIXED MEDIA 71
CONDENSED MATTER AT HIGH PRESSURE 71
OPPORTUNITIES 73
2 Structures and Vibrational Properties of Solids 76
INTRODUCTION 76
THEORETICAL CALCULATIONS 77
MEASUREMENTS OF STRUCTURES AND PHONON SPECTRA 79
PHONON TRANSPORT 82
ELECTRON-PHONON INTERACTIONS 83
DISORDERED SOLIDS AND INCOMMENSURATE PHASES 87
PHASE TRANSITIONS AND NONLINEAR EXCITATIONS 89
OPPORTUNITIES 90
3 Critical Phenomena and Phase Transitions 93
INTRODUCTION 93
WHAT ARE CRITICAL PHENOMENA, AND WHY ARE THEY INTERESTING TO PHYSICISTS? 93
EXAMPLES OF PHASE TRANSITIONS AND CRITICAL POINTS 95
HISTORY 96
WHAT DOES ONE MEASURE? 98
WHAT DETERMINES THE UNIVERSALITY CLASS? 102
EXPERIMENTAL REALIZATIONS OF LOW-DIMENSIONAL SYSTEMS 105
MULTICRITICAL POINTS 106
SYSTEMS WITH ALMOST-BROKEN SYMMETRY 106
Two-Dimensional Superfluid and XY Model 107
Melting of a Two-Dimensional Crystal 107
Smectic A-to-Nematic Transition 108
QUENCHED DISORDER 109
PERCOLATION AND THE METAL-INSULATOR TRANSITION IN DISORDERED SYSTEMS 110
NONEQUILIBRIUM SYSTEMS 110
FIRST-ORDER TRANSITIONS 110
OUTLOOK 111
4 Magnetism 113
INTRODUCTION 113
MAGNETIC INSULATORS 115
Low-Dimensional Systems 115
Critical Phenomena 118
METALLIC MAGNETS 118
Transition-Metal Ferromagnets 118
Rare-Earth and Actinide Magnets 121
DISORDERED SYSTEMS 123
Introduction 123
Disordered Ferromagnets, Antiferromagnets, and Paramagnets 124
Spin Glasses 126
COMPUTER SIMULATIONS IN MAGNETISM 128
FUTURE DEVELOPMENTS 130
5 Semiconductors 131
INTRODUCTION 131
SURFACES AND INTERFACES 133
DEFECTS IN SEMICONDUCTORS 135
REDUCED DIMENSIONALITY IN SEMICONDUCTORS 136
OPTICAL PROPERTIES OF COMPOUND SEMICONDUCTORS 137
AMORPHOUS SEMICONDUCTORS 139
FUTURE PROSPECTS 140
Semiconductor Surfaces and Interfaces 140
SEMICONDUCTOR-SEMICONDUCTOR INTERFACES 141
SEMICONDUCTOR-INSULATOR INTERFACES 141
SEMICONDUCTOR-METAL INTERFACES 142
Defects in Semiconductors 142
Systems of Reduced Dimensionality 143
QUANTIZED HALL EFFECT 143
GROWTH TECHNIQUES AND LITHOGRAPHY 143
SMALL STRUCTURES 143
HETEROSTRUCTURES 144
THE TWO-DIMENSIONAL WIGNER CRYSTAL 144
6 Defects and Diffusion 145
INTRODUCTION 145
NEW FIELDS FROM OLD: AN EXAMPLE 146
Phase Microstructure and Phase Generation in Radiation Fields 147
Surface and Near-Surface Probes 148
Ion-Beam Microfabrication 149
CALCULATIONS OF DEFECT STRUCTURE 150
FUNDAMENTALS OF ATOMIC MOBILITY 152
COMMENTS ON ACTIVE AREAS 155
Point Defects in Simple Solids 155
Surface Diffusion 156
Photochemical Processes 157
Molecular Dynamics 157
Dislocation Motion in Glasses 158
Defect Imaging at Atomic Resolution 159
SOME DIRECTIONS FOR FUTURE RESEARCH 160
7 Surfaces and Interfaces 162
INTRODUCTION 162
THE STRUCTURE OF THE CRYSTAL SURFACE 165
SPECTROSCOPY AND ELEMENTARY EXCITATIONS ON THE SURFACE 169
INTERACTIONS OF ATOMS AND MOLECULES ON THE SURFACE 173
THE INTERFACE BETWEEN SOLIDS AND DENSE MEDIA 175
THEORY 177
OPPORTUNITIES 178
8 Low-Temperature Physics 182
DEFINITION OF SUBFIELD 182
QUANTUM FLUIDS 182
Superfluid 3He 184
NUCLEAR MAGNETIC RESONANCE IN SUPERFLUID 3HE 188
ULTRASOUND 188
OTHER SOUND MODES 189
DEFECTS 189
SUPERFLUID FLOW AND HYDRODYNAMICS 190
Novel Quantum Fluids 190
MIXTURES OF 3HE IN 4HE 191
SPIN-POLARIZED HYDROGEN AND DEUTERIUM 191
LIQUID 4HE IN UNUSUAL GEOMETRIES 192
ELECTRONS ON HELIUM SURFACES 193
SUPERCONDUCTIVITY 194
Nonequilibrium Superconductivity 197
Novel Superconducting Materials 197
Magnetic Superconductors 198
High-Transition-Temperature, High-Magnetic-Field Materials 198
The Josephson Effects 200
QUANTUM CRYSTALS 200
LOW-TEMPERATURE TECHNOLOGY 203
RESEARCH OPPORTUNITIES IN LOW-TEMPERATURE PHYSICS 205
9 Liquid-State Physics 208
CLASSICAL LIQUIDS 208
Introduction 208
Static Properties 209
Dynamical Properties of Classical Liquids 211
Colloidal Systems\u2014Soap Solutions 216
LIQUID CRYSTALS 217
What Are Liquid Crystals? 217
Why Are Liquid Crystals Interesting? 218
Major Advances 220
OPPORTUNITIES FOR FUTURE WORK 221
10 Polymers 224
INTRODUCTION 224
RESEARCH PROBLEMS 225
Amorphous State\u2014Solutions and Melts 225
Glass 227
Elastomers, Gels, Cross-linked Networks 227
Polymer Crystals 228
Electrical Properties 229
Other Polymer Properties 230
OPPORTUNITIES 231
11 Nonlinear Dynamics, Instabilities, and Chaos 233
INTRODUCTION 233
MAJOR ADVANCES 234
A New Paradigm 234
New Experimental Methods 235
Routes to Chaos 235
Dynamical Systems Theory of the Routes to Turbulence 237
Dynamical Systems Analysis of Experiments 239
Nonlinear Stability Theory 240
Pattern Evolution 241
Instabilities in Other Dissipative Systems 241
Nonlinear Dynamics of Conservative Systems 243
General Remarks 244
CURRENT FRONTIERS 245
Bifurcation Sequences 245
Patterns 246
Numerical Simulations 246
Experimental Methods 247
Transition from Weak to Fully Developed Turbulence 247
Conservative Systems 248
Nonequilibrium Systems 249
New Directions 250
Appendixes 253
B New Experimental Techniques 264
C New Materials 266
INTRODUCTION 266
NEW MATERIALS IN THE LAST DECADE 267
One- and Two-Dimensional Transition-Metal Chalcogenides 267
Materials with Open-Crystal Structures 268
The Magnetic Superconductors 268
Organic Conductors 268
New Superconductors 269
Glasses 269
Artificially Structured Materials 269
IMPACT OF NEW SYNTHESIS TECHNIQUES ON CONDENSED-MATTER PHYSICS 270
Thin Metallic Films 270
Epitaxial Materials 270
Metallic Superlattices 272
Materials Modification 272
Filamentary Materials 273
Metal Clusters 273
MAJOR CONCERNS 274
PROJECTIONS FOR THE FUTURE 274
D Laser Spectroscopy of Condensed Matter 276
INTRODUCTION 276
ACCOMPLISHMENTS OF THE PAST DECADE 277
Nonlinear Optical Spectroscopy 277
TWO-PHOTON SPECTROSCOPY 277
HOLE BURNING IN INHOMOGENEOUSLY BROADENED SPECTRA 277
OTHER NONLINEAR SPECTROSCOPY TECHNIQUES 278
Transient Optical Spectroscopy 278
Ultrafast Laser Spectroscopy 279
PICOSECOND LASER SPECTROSCOPY 279
FEMTOSECOND LASER SPECTROSCOPY 280
SOME DIRECTIONS FOR FUTURE RESEARCH 280
E National Facilities 283
INTRODUCTION 283
SYNCHROTRON RADIATION RESEARCH 285
Introduction 285
Summary of Present Synchrotron Facilities in the United States 285
Cornell High Energy Synchrotron Source (CHESS) 285
National Synchrotron Light Source (NSLS) 286
Stanford Synchrotron Radiation Laboratory (SSRL) 286
Synchrotron Radiation Center (SRC) 287
Synchrotron Ultraviolet Radiation Facility (SURF) 287
Research Highlights of the Past Decade 288
Future Directions in Synchrotron Research 293
NEUTRON-SCATTERING FACILITIES 295
Description of Existing U.S. Facilities 295
Research Highlights of the 1970s 296
Future Directions 300
Epithermal Neutrons 301
Neutron Guides 301
High-Resolution Spectroscopy 302
Interferometry 302
Growth of the Neutron User Community 302
HIGH-MAGNETIC-FIELDS FACILITIES 303
Description of U.S. Facilities 303
Research Highlights of the 1970s 303
Opportunities 304
FACILITIES FOR ELECTRON MICROSCOPY 305
Introduction 305
Description of U.S. Facilities 306
Advances of the Past Decade in Electron Microscopy 307
Outlook for the Future 308
Contributors to This Volume 309
PART I 309
CHAPTER 1 309
CHAPTER 2 310
CHAPTER 3 310
CHAPTER 4 310
CHAPTER 5 311
CHAPTER 6 311
CHAPTER 7 311
CHAPTER 8 311
CHAPTER 9 311
CHAPTER 10 312
CHAPTER 11 312
APPENDIX D 312
APPENDIX E 312
Index 313