Ordering in Strongly Fluctuating Condensed Matter Systems

Ordering in Strongly Fluctuating Systems: Introductory Comments.- 1. Introduction.- 2. A Theorist’s Ideal Glass.- 3. Systems Far From Equilibrium.- Phase Transitions in Low-Dimensional Systems and Renormalization Group Theory.- 1. Phase Transitions and Some Simple Spin Models.- 2. Fluctuations and the Lower Critical Dimension.- 3. Values of Lower Critical Dimensionality for Some Spin Models.- 4. Fluctuations.- 5. Introduction to the Renormalization Group.- Real-Space Renormalization-Group Method for Quantum Systems.- Upper Marginal Dimensionality, Concept and Experiment.- 1. Phenomenological Description.- 2. Mean Field Theory.- 3. Ginzburg Criterion.- 4. Experiments on LiTbF4.- 5. Conclusion.- Lower Marginal Dimensionality. X-Ray Scattering from the Smectic-A Phase of Liquid Crystals.- 1. Introduction.- 2. The Nematic and Smectic A Phases of Liquid Crystals.- 3. The Correlation Function in the Harmonic Approximation.- 4. Experiment and Analysis.- 5. Results and Conclusions.- Appendix: Calculation of $$$$ in the SmA Phase.- Critical Fluctuations Under Shear Flow.- 1. Turbidity: TC change.- 2. The scattered light: Anisotropy; mean-field; lowering of UCD?.- 3. Discussion.- 4. “Moralité”.- Lifshitz Points in Ising Systems with Competing Interactions.- 1. Introduction.- 2. One-dimensional Ising Systems with competing Interactions.- 3. Two-dimensional Ising systems.- 4. Conclusions.- Elementary Excitations in Magnetic Chains.- 1. Introduction.- 2. Magnons in XY-like Magnetic Chains.- 3. The Anisotropic, Classical XY Chain.- 3.1 The Model.- 3.2 Intuitive Analysis at Low Temperature for q = 2 and J = 0.- 3.3 Energy of a Wall.- 3.4 Number of Walls.- 3.5 Antiferromagnets in a Magnetic Field.- 4. A Simple Dynamical Model: The Almost — Ising Antiferromagnetic Chain.- 4.1 The Model.- 4.2 Collisions Between Two Solitons.- 5. Propagation of Broad Walls.- Experimental Studies of Linear and Nonlinear Modes in 1-D-Magnets.- 1. Real Systems; Experimental Methods.- 2. Linear Excitations.- 3. Nonlinear Excitations.- Q-Dependence of the Soliton Response in CsNiF3 At.- T = 10K and H =5kG.- Dynamics of the Sine-Gordon Chain: The Kink-Phonon Interaction, Soliton Diffusion and Dynamical Correlations.- 1. Statement of the Problem.- 2. A Kink-Phonon Collision.- 3. Diffusive Motion of the Kink.- 4. Dynamical Correlation Functions.- The Spin-Wave Continuum of the S=1/2 Linear Heisenberg Antiferrornagnet.- Excitations and Phase Transitions in Random Anti-Ferromagnets.- Neutron Scattering.- Critical Phenomena at Phase Transitions.- Percolation.- Excitations of Dilute Magnets Near the Percolation Threshold.- Critical Properties of the Mixed Ising Ferromagnet.- Structure and Phase Transitions in Physisorbed Monolayers.- History and Background.- Statistical Thermodynamics of Physical Adsorption.- Structural Investigations of Monolayers.- Substrate Influences.- Commensurate-Incommensurate Transition and Orientational Epitaxy.- Antiferromagnetism in 0« Films.- Conclusion.- Two-Dimensional Solids and Their Interaction with Substrates.- I. Collective Phenomena and Phase Transitions in Two Dimensions.- 1.1 Early Theoretical Works.- 1.2 Experimental Situation.- II. Effect of Substrate.- II.1 Two-Dimensional Solids and Adsorbed Layers.- II.2 Substrate Distortion and Related Effects.- II.3 Chemical Potential.- II.4 Substrate Potential.- II.5 Conclusion.- III. Walls and Domains.- III.1 A One-Dimensional Model.- III.2 The Theory of Frank and Van der Merwe.- III.3 Aubry’s Theory.- III.4 Domains and Walls for Dimensions Larger than 1.- IV. The Pokrovskii-Talapov Model.- IV.1 Hypotheses.- IV.2 Solution.- IV.3 Bragg Singularities.- IV.4 The Pinning Transition.- V. Rate Gas Monolayers on Graphite or Lamellar Halides.- V.1 Introduction.- V.2 The Zero Temperature Theory of Bak, Mukamel, Villain and Wentowska.- V.3 Rare Gas Monolayers on Hexagonal Substrates at T i 0.- V.4 Effect of Substrate Distortions.- VI. The Novaco-Mc Tague Orientational Instability.- VI.1 General Argument.- VI.2 Case of Parallel Walls.- VI.3 Case of a Regular Network of Intersecting Walls.- VI.4 Finite Temperatures.- VI.5 Microscopic Theories.- Appendix A. Bragg Singularities of a 2-D, Harmonic Crystal.- Appendix B. Interaction between two Solutions.- Appendix C. Partition function of the Pokrovskii-Talapov Model Near the Commensurable-Incommensurable Transition.- Appendix D. Bragg Singularities of the Pokrovskii-Talapov Model Near the C-I Transition.- Appendix E. The Roughening Transition.- The Dislocation Theory of Melting: History, Status and Prognosis.- 1. Introduction.- 2. History.- 3. Status.- 4. Prognosis.- The Kosterlitz-Thouless Theory of Two-Dimensional Melting.- Phase Transitions and Orientational Order in a Two-Dimensional Lennard-Jones System.- The Roughening Transition.- I. Introduction.- II. The solid-On-Solid Model.- III. The BCF Argument.- IV. Experimental Results.- V. Monte Carlo Calculations: Qualitative Features.- VI. Static Critical Behavior.- VII. Roughening Dynamics and the Kosterlitz Renormalization Group Method.- VIII.The FSOS Model and Mc Calculations.- IX. Final Remarks.- Statics and Dynamics of the Roughening Transition: A Self-Consistent Calculation.- I. Introduction.- II. Roughening Transition.- III. Two-Dimensional Planar Model.- IV. Conclusions.- Fluctuations in Two-Dimensional Six-Vertex Systems.- Light Scattering Studies of the Two-Dimensional Phase Transition in Squaric Acid.- 1. Introduction.- 2. Light Scattering Studies.- 3. Order Parameter.- 4. Order Flucatuations.- 5. Peak Shape and Width.- 6. Disorder Induced Scattering.- 7. Conclusions.- Monte Carlo Simulation of Dilute Systems and of Two-Dimensional Systems.- I. Introduction.- II. Ferromagnets Diluted with Nonmagnetic Impurities and Related Systems.- III. Models for Quasi-Two-Dimensional (2D) Magnets.- IV. Lattice Gas Models for Adsorbed Monolayers at Surfaces.- Order and Fluctuations in Smectic Liquid Crystals.- I. Introduction.- II. The Nematic Phase.- III.The Nematic-Smectic A Transition and The Smectic A Phase.- IV. The Smectic C Phase and Smc-SmA Transition.- v. Liquid Crystals and Lower Dimensional Physics.- Dislocations and Disclinations in Smectic Systems.- Translational Defects.- Orientational Defects.- Non-Elementary Defects.- Observation of Dislocations.- Dislocation Motion.- “Pair Creation” of Disclinations.- Defects and Phase Transitions.- Fluctuations and Freezing in a One-Dimensional Liquid:Hg3-?AsF6.- The Model Hamiltonian.- High Temperature Properties (T > TC).- Long Range Order.- Dynamics.- The Effect of Pressure on the Modulated Phases of TTF-TCNQ.- Spin Glasses A Brief Review of Experiments, Theories, and Computer Simulations.- 1. Spin Glass Materials and Experiments.- 2. Theoretical Models and Concepts.- 3. Spin-Glass Freezing: Phase Transition or Nonequilibrium Effect?.- 4. Conclusions and Outlook.- Random Anisotropy Spin-Glass.- Exact Results for a One-Dimensional Random-Anisotropy Spin Glass.- On Critical Slowing-down in Spin Glasses.- Participants.