This book, edited by M. A. Ramos and contributed by several reputed physicists in the field, presents a timely review on low-temperature thermal and vibrational properties of glasses, and of disordered solids in general. In 1971, the seminal work of Zeller and Pohl was published, which triggered this relevant research field in condensed matter physics. Hence, this book also commemorates about 50 years of that highlight with a comprehensive, updated review. In brief, glasses (firstly genuine amorphous solids but later on followed by different disordered crystals) were found to universally exhibit low-temperature properties (specific heat, thermal conductivity, acoustic and dielectric attenuation, etc.) unexpectedly very similar among them — and very different from those of their crystalline counterparts. These universal "anomalies" of glasses and other disordered solids remain very controversial topics in condensed matter physics. They have been addressed exhaustively in this book, through many updated experimental data, a survey of most relevant models and theories, as well as by computational simulations.
Author(s): Miguel A. Ramos
Publisher: World Scientific Publishing
Year: 2022
Language: English
Pages: 504
City: London
Contents
Preface
Chapter 1. Introduction: About 50 Years of Two-Level Systems and Boson Peak
1. Introduction
2. How Universal Are “Universal Anomalies” of Glasses?
3. Aim and Contents of this Book
References
Chapter 2. Low-Temperature Specific Heat of Glasses and Disordered Crystals
1. Introduction
2. The Specific Heat of Glasses vs Crystals
2.1. The specific heat below 1 K
2.2. The specific heat above 1 K
3. Glassy Features in Disordered Crystals
3.1. Mixed crystals
3.2. Orientationally-disordered crystals (“glassy crystals”)
3.3. Other disordered crystals with glassy behavior
4. Low-temperature Specific Heat of Highly-stable Glasses
5. Theories and Models
5.1. Tunneling Model
5.2. The maximum in Cp/T3 in glasses and in crystals
5.3. Soft potential model
5.4. Other theories and approaches
6. Discussion: How Universal is the Linear Term in the Specific Heat of Glassy Materials
7. Conclusion and Outlook
References
Chapter 3. Thermal Conductivity of Glasses and Disordered Crystals
1. Introduction
2. Low-Temperature Thermal Conductivity Data
2.1. Studies in the decade 1971–1980
2.2. Studies in the decade 1981–1990
2.3. Studies in the decade 1991–2000
2.4. Studies in the decade 2001–2010
2.5. Studies in the decade 2011–2020
3. Theoretical Descriptions
3.1. Standard Tunneling Model
3.2. Soft-potential model
4. Recapitulation
Acknowledgments
References
Chapter 4. Two-Level Systems and the Tunneling Model: A Critical View
1. Introduction
1.1. Standard model of two-level systems
1.2. Crossover region
2. Beyond the Standard Model of Two-Level Systems
2.1. Interacting two-level systems
2.2. Universally small phonon scattering
2.3. Exceptions to the rule
3. Mysteries about Glasses at Low Temperatures: Open Questions for the Future
4. Future Outlook
Acknowledgments
References
Chapter 5. Exceptions Leading to a New Theory of Universality: Amorphous Solids without Glassy Properties
1. Introduction
1.1. Fragile and strong glasses
2. Anomalous Properties of Glasses at Low Temperatures
2.1. Random first-order transition theory
2.2. The standard tunneling model
3. Amorphous Solids without Glassy Properties
3.1. Connection between TLS and structure
4. Universal and Non-universal Values of TLSs
4.1. Interaction of TLSs with elastic fields: The coupling constant
4.2. Interaction of TLSs with elastic and electric fields
5. Conclusions and Perspectives
References
Chapter 6. Vibrational Dynamics of Non-Crystalline Solids
1. Introduction
2. Vibrational Density of States
2.1. Boson peak shape and intensity
2.2. Boson peak dependence on external parameters
2.3. Boson peak as a broadened van-Hove singularity
3. Dispersion and Scattering of Vibrational Modes
3.1. Dynamic structure factor
3.2. Single damped harmonic oscillator analysis
3.2.1. Dispersion of the inelastic peak position
3.2.2. Peak broadening and the Ioffe-Regel limit
3.2.3. Rayleigh-like scattering and negative dispersion
3.2.4. Sound attenuation in glasses
3.3. Evidences of two excitations
3.4. Dynamics of glasses and corresponding polycrystals
4. Conclusions
References
Chapter 7. Low-frequency Vibrational Spectroscopy of Glasses
1. Introduction
1.1. Thermal properties
1.1.1. Heat capacity
1.1.2. Thermal conductivity
1.2. Vibrations in glasses
2. Inelastic Spectroscopy
2.1. Dispersion diagram and experimental techniques
2.2. Inelastic scattering intensity
2.3. Coherent and incoherent scattering
3. Spectroscopy of Acoustic Phonons
3.1. Attenuation and sound velocity in dielectric crystals
3.2. Attenuation and sound velocity in glasses
3.2.1. Ultrasonics and mechanical techniques
3.2.2. Brillouin light scattering
3.2.3. Inelastic scattering of UV radiation
3.2.4. Picosecond ultrasonics
3.2.5. Inelastic neutron and X-ray scattering
4. Spectroscopy of the Low-frequency Region of the vDOS
4.1. Inelastic neutron scattering
4.2. Inelastic spectroscopies of light
4.3. Nuclear inelastic scattering
4.4. Inelastic X-ray scattering
References
Chapter 8. The Soft-Potential Model and Its Extensions
1. Introduction
2. The Soft-Potential Model
2.1. The anharmonic quartic potential
2.2. Assumptions
2.3. The nature of the soft modes
3. Achievements of the Soft-Potential Model
3.1. Tunneling states below 1 K
3.2. Vibrational soft modes above 1 K
3.3. Plateau in the thermal conductivity
3.4. Sound absorption at low frequency
3.5. Sound absorption at high frequency
4. Limitations and Extensions
4.1. Boson peak
4.2. Thermally activated relaxation
References
Chapter 9. Heterogeneous Elasticity: The Tale of the Boson Peak
1. Introduction
2. “Scalar Elasticity” and Diffusion-vibration Analogy
2.1. Diffusion-vibration analogy
2.2. Low-frequency limit: Born approximation, Rayleigh scattering, and long-time tails
2.3. Weak disorder and the SCBA
2.4. Strong disorder and the CPA
3. Heterogeneous Elasticity Theory
3.1. Model
3.2. SCBA
3.3. General features of the disorder-induced vibrational anomalies: Comparison of the SCBA version of heterogeneous elasticity theory with a simulation
3.4. CPA
4. Discussion and Conclusions
References
Chapter 10. Computational Simulations of the Vibrational Properties of Glasses
1. Introduction
2. Simulation Models
2.1. Molecular Dynamics (MD) simulations
2.2. Glass and inherent structure
3. Vibrational Eigenmodes
3.1. General description
3.2. Vibrational eigenmodes in elastic media (elastic waves)
3.3. Vibrational eigenmodes in crystals (phonons)
3.4. Vibrational eigenmodes in glasses
3.5. Vibrational density of states
3.6. Characterization of vibrational eigenmodes
3.6.1. Participation ratio
3.6.2. Phonon order parameter
4. Phonon Transport
4.1. Dynamic structure factor
4.2. Propagation frequency and attenuation rate
4.3. Ioffe-Regel (IR) frequency
4.4. Zero-temperature measurement
4.4.1. Dynamic structure factor in the zero-temperature limit
4.4.2. Direct measurement at zero temperature
5. Elastic Deformation
5.1. General description
5.1.1. Elastic modulus tensor
5.1.2. Bulk, pure shear, and simple shear elastic moduli
5.1.3. Affine and non-affine elastic moduli
5.2. Fluctuation formulation
5.2.1. Finite temperature T > 0
5.2.2. Zero-temperature limit T → 0
5.3. Direct measurement
6. Recent Advances in the Vibrational Properties of Glasses
6.1. Vibrational eigenmodes in glasses
6.2. Phonon transport in glasses
References
Chapter 11. Topological Phases of Amorphous Matter
1. Introduction
2. A Primer on Topological Matter: The Role of Symmetry
2.1. Basic properties of topological states: Atomic obstructions and quantized observables
2.2. Strong topological insulators, gapless surface states, and symmetry classifications
2.3. Topological metals
2.4. Topological phases in non-electronic systems
3. Topological Phases Beyond Crystalline Solids
3.1. Half a step towards amorphous topological matter: Disorder, quasi-crystals, and Moiré lattices
3.2. Modeling amorphous topological matter
3.3. Physical properties and theoretical characterization of amorphous topological matter
3.3.1. Local markers
3.3.2. Responses to external fields
3.3.3. Symmetry indicators and effective Hamiltonians
3.3.4. Other probes
3.4. Experimental realizations and promising platforms
3.4.1. Condensed matter systems
3.4.2. Synthetic systems
4. Conclusions and Outlook
Acknowledgments
References
Index
