Collective Excitations in Solids

Spectroscopies of Plasmons.- References.- From Magnons to Solitons.- Abstract.- I. Introduction.- II. Magnons.- III. MagnonMagnon Forces.- IV. TwoMagnon Bound States.- V. ManyBody Scattering Theory.- VI. XY Model: A Model Antiferromagnet.- VII. Heisenberg Antiferromagnet: Ground State.- VIII. Some Consequences.- IX. Effects of Surfaces on Magnons.- X. Magnons vs. Solitons.- XI. Soliton Solutions.- References.- Quasiparticles in Magnetic Metals.- Abstract.- I. Introduction.- II. Low Density Electron Gas.- III. Criterion for Magnetic Ground State.- IV. Quasiparticles.- V. Nearly HalfFilled Band: Nagaoka's Theory.- VI. Two or More Magnetic SubBands.- VII. Magnons in Metals.- VIII. Antiferromagnetism in Metals.- Polaritons.- Abstract.- I. Introduction.- II. Bulk Polariton Linear Response.- III. Experiments on Bulk Polaritons.- IV. Surface Polariton Linear Response.- V. Experiments on Surface Polaritons.- VI. Conclusion.- References 49.- Polarons.- Abstract.- I. Introduction.- II. The LandauPekar StrongCoupling Theory.- III. FieldTheory Formalism, Fröhlich's Hamiltonian and WeakCoupling Theory.- IV. Other Methods for Large (Fröhlich) Polarons.- V. Small Polarons and SelfTrapping.- References.- Long Seminars.- Surface Collective Excitations.- Collective Excitations in Concentrated Mn2+ Systems: Spectral Properties.- Optical Dynamics in Concentrated Mn2+ Systems.- Spectroscopy of Stoichiometric Laser Materials: Excitons or Incoherent Transfers?.- Exciton-Hole Droplets in Semiconductors.- Excitons and Plasmons: Collective Excitations in Semiconductors.- Picosecond ExcitonPhenomena in Chlorophyll Complexes (Abstract only).- Bose-Einstein Statics in Exciton Systems.- Small Polarons in Biological Systems (Abstract only).- Short Seminars (Abstracts).- Perspectives of Free Electron Lasers in Solids.- The Dispersion Curves of Excitonic Polaritons and Their Distortion with Increasing Density.- Motion of a Magnon Soliton About a Phonon Soliton in a Onedimensional Ferromagnet.- Interconfiguration Fluctuations.- Luminescence of Mn2+ IN RbMnxMg1xF3.- Effect of Hydrostatic Pressure on the Luminescence Spectra of the S2 Centre and the EPR of This S2 Centre for the Crystal Scapolite.- On the Calculation of Polaron Wavefunction in the Static Electronlattice Coupling.- Semiconductor Surface Inversion Layers and Their Collective Modes.- Concluding Article.- Present Trends in Collective Excitations in Solids.- Contributors.