Experimental Studies Of Boson Fields In Solids

by Ulrich Kobler, Andreas Hoser

Overview

This book provides a new understanding of the large amount of experimental results gained in solid state physics during the last seven decades. For more than 160 different materials, data analyses shown in terms of atomistic models (Hamiltonians) have not provided a quantitatively satisfactory description of either excitation spectra or dynamic properties. Instead, the experimental evidences have elaborated that field theories are necessary. However, most experimentalists are not familiar with field theories, and realistic field theories of magnetism are absent.The book illustrates in an empirical way the elements of future field theories of solid state physics with special emphasis on magnetic materials. In contrast to the many available textbooks on quantum field theories that emphasize more on algorithmic formalities rather than referring to the experimental facts, the approach in this book is pragmatic instead of abstract theoretic. This methodical concept considerably facilitates experimentalists to get acquainted with the basic ideas of field theories, even if a ready field theory is not provided by this experimental study.

Product Details

ISBN-13:	9789813235489
Publisher:	World Scientific Publishing Company, Incorporated
Publication date:	11/07/2018
Pages:	964
Product dimensions:	6.69(w) x 9.61(h) x 2.00(d)

Table of Contents

Preface v

1 Introduction 1

2 History of Conventional Spin Wave Theory 71

2.1 Theoretical and Experimental Confusions 71

2.2 Problems with the Macroscopic Magnetization 81

3 Basic Issues of Renormalization Group (RG) Theory 100

3.1 Boson Fields in Non-Magnetic Insulators 100

3.2 Boson fields in Ordered Magnets 128

4 Universality 140

4.1 Non-Magnetic Solids 140

4.2 Ordered Magnets 149

4.3 Non-Universal Behavior 164

4.4 Coexistence of Universality Classes 182

5 Microscopic Processes 219

6 Relevant and Non-Relevant Magnons 230

6.1 Non-Relevant Magnons 230

6.2 Relevant Magnons 289

7 Crossover Phenomena 295

7.1 Amplitude Crossover (AC) 295

7.2 Quantum State Crossover (QS) 309

7.3 Crossover Between Critical Points (CP) 324

7.4 Symmetry Crossover (SC) 332

7.5 Dimensionality Crossover (DC) 340

8 Metastability of Universality Classes 349

9 Relevant and Non-Relevant Interactions 380

10 Temperature Dependence of the Magnon Excitation Spectra 418

11 Magnetic Heat Capacity 435

11.1 Non-Relevant Magnetic Heat Capacity for T→0 435

11.2 Relevant Magnetic Heat Capacity for T→0 445

12 Experimental Verification of GSW Bosons 475

13 Magnets With and Without Magnon Gap 508

13.1 Isotropic Magnets with Half-Integer Spin (T² Universality Class) 513

13.2 Isotropic Magnets with Integer Spin (T^9/2 Universality Class) 517

13.3 Two-Dimensional Magnets with Half-Integer Spin (T^3/2 Universality Class) 520

13.4 Two-Dimensional Magnets with Integer Spin (T² Universality Class) 525

13.5 One-Dimensional Magnets with Half-Integer Spin (T^5/2 Universality Class) 526

13.6 One-Dimensional Magnets with Integer Spin (T³ Universality Class) 527

13.7 Field Dependence of the Classical Magnon Spectrum 542

13.8 Interactions Between Magnons and GSW Bosons 549

14 Microscopic Details: Spin Structure, Site Disorder, Two Order Parameters 594

15 Boson Fields at the Magnetic Ordering Transition 621

15.1 Isotropic 3D Magnets with Half-Integer Spin (T² Universality Class) 667

15.2 Isotropic 3D Magnets with Integer Spin (T^9/2 Universality Class) 682

15.3 Two-Dimensional Magnets with Integer Spin (T² Universality Class) 701

15.4 Two-Dimensional Magnets with Half-Integer Spin (T^3/2 Universality Class) 707

15.5 One-Dimensional Magnets with Integer Spin (T³ Universality Class) 713

15.6 One-Dimensional Magnets with Half-Integer Spin (T^5/2 Universality Class) 729

16 Thermal Lattice Expansion and Magnetostriction 742

16.1 Spontaneous Magnetostriction 744

16.2 Thermal Lattice Expansion of Non-Magnetic Solids 768

16.3 Interactions Between Phonons and Debye Bosons 781

16.4 Thermal Conductivity of Insulators 807

16.5 Thermal Conductivity of Metals 826

17 Boson Fields Near Melting Transition 840

18 Boson Fields in Conventional Superconductors 860

18.1 Superconducting Heat Capacity 871

18.2 Superconducting Excitation Gap 894

19 Summary 905

Bibliography 921

Substance Index 945