This book comprehensively presents an unconventional quantum criticality caused by valence fluctuations, which offers theoretical understanding of unconventional Fermi-liquid properties in cerium- and ytterbium-based heavy fermion metals including CeCu2(Si,Ge)2 and CeRhIn5 under pressure, and quasicrystal β-YbAlB4 and Yb15Al34Au51. The book begins with an introduction to fundamental concepts for heavy fermion systems, valence fluctuation, and quantum phase transition, including self-consistent renormalization group theory. A subsequent chapter is devoted to a comprehensive description of the theory of the unconventional quantum criticality based on a valence transition, featuring explicit temperature dependence of various physical quantities, which allows for comparisons to relevant experiments. Lastly, it discusses how ubiquitous the valence fluctuation is, presenting candidate materials not only in heavy fermions, but also in strongly correlated electrons represented by high-Tc superconductor cuprates. Introductory chapters provide useful materials for learning fundamentals of heavy fermion systems and their theory. Further, experimental topics relevant to valence fluctuations are valuable resources for those who are new to the field to easily catch up with experimental background and facts.

This book comprehensively presents an unconventional quantum criticality caused by valence fluctuations, which offers theoretical understanding of unconventional Fermi-liquid properties in cerium- and ytterbium-based heavy fermion metals including CeCu2(Si,Ge)2 and CeRhIn5 under pressure, and quasicrystal β-YbAlB4 and Yb15Al34Au51. The book begins with an introduction to fundamental concepts for heavy fermion systems, valence fluctuation, and quantum phase transition, including self-consistent renormalization group theory. A subsequent chapter is devoted to a comprehensive description of the theory of the unconventional quantum criticality based on a valence transition, featuring explicit temperature dependence of various physical quantities, which allows for comparisons to relevant experiments. Lastly, it discusses how ubiquitous the valence fluctuation is, presenting candidate materials not only in heavy fermions, but also in strongly correlated electrons represented by high-Tc superconductor cuprates. Introductory chapters provide useful materials for learning fundamentals of heavy fermion systems and their theory. Further, experimental topics relevant to valence fluctuations are valuable resources for those who are new to the field to easily catch up with experimental background and facts.

This unique monograph covers recent theoretical and experimental results on the complex character of f electrons in materials containing lanthanides (rare earths) or actinides, such as alpha-cerium and delta-plutonium. It answers the urgent need for a general presentation of the body of experimental and theoretical results presently available in this challenging domain. Some of the fast developing applications of lanthanide and actinide materials are mentioned. Materials containing atoms with an open f shell have electronic and crystalline properties that are controlled by the localized or delocalized character of the f electrons. This book gives a theoretical discussion of the various spectroscopic methods that shed light on the character of the f electrons and on the connection between their localization and the properties of these materials. Part 1 covers the characteristics of the f electrons in atoms and solids and includes a discussion of the properties of lanthanides and actinides in connection with the f electrons. Part 2 describes the various spectroscopic methods that are used to establish the electronic distributions and energies of the states. Examples involve the determination of f electron distributions by high energy spectroscopy methods with separate treatment of the valence and core electrons. Part 3 concentrates on the theoretical treatment of electronic transitions involving f electrons and simulations of the lanthanide spectra, including comparison with the available experimental data. Part 4 discusses the localized or delocalized character of the f electrons in actinides and their compounds, including comparison (analogies & differences) between the 4f and 5f electron materials. This monograph should be of great value for researchers, academics and engineers working in the fields of high energy spectroscopy, electronic and nuclear science and technology, as well as materials involving rare earths and radio-elements.

Describing the physical properties of quantum materials near critical points with long-range many-body quantum entanglement, this book introduces readers to the basic theory of quantum phases, their phase transitions and their observable properties. This second edition begins with a new section suitable for an introductory course on quantum phase transitions, assuming no prior knowledge of quantum field theory. It also contains several new chapters to cover important recent advances, such as the Fermi gas near unitarity, Dirac fermions, Fermi liquids and their phase transitions, quantum magnetism, and solvable models obtained from string theory. After introducing the basic theory, it moves on to a detailed description of the canonical quantum-critical phase diagram at non-zero temperatures. Finally, a variety of more complex models are explored. This book is ideal for graduate students and researchers in condensed matter physics and particle and string theory.

' This book presents, in the form of reviews by world''s leading physicists in wide-ranging fields in theoretical physics, the influence and prescience of Skyrme''s daring idea of 1960, originally conceived for nuclear physics, that fermions can arise from bosons via topological solitons, pervasively playing a powerful role in wide-ranging areas of physics, from nuclear/astrophysics, to particle physics, to string theory and to condensed matter physics. The skyrmion description, both from gauge theory and from gauge/gravity duality, offers solutions to some long-standing and extremely difficult problems at high baryonic density, inaccessible by QCD proper. It also offers explanations and makes startling predictions for fascinating new phenomena in condensed matter systems. In both cases, what is at the core is the topology although the phenomena are drastically different, even involving different spacetime dimensions. This second edition has been expanded with addition of new reviews and extensively updated to take into account the latest developments in the field. Contents:Hadrons and Nuclear Matter:Skyrmions and Nuclei (R A Battye, N S Manton and P M Sutcliffe)States of Carbon-12 in the Skyrme Model (P H C Lau and N S Manton)Electromagnetic Form Factors of the Nucleon in Chiral Soliton Models (G Holzwarth)Exotic Baryon Resonances in the Skyrme Model (D Diakonov and V Petrov)Heavy-Quark Skyrmions (N N Scoccola)Pentaquark Candidates P+c(4380) and P+c(4450) within the Soliton Picture of Baryons (N N Scoccola, D O Riska and M Rho)Skyrmion Approach to Finite Density and Temperature (B-Y Park and V Vento)Fractionized Skyrmions in Dense Compact-Star Matter (M Harada, Y-L Ma, H K Lee and M Rho)The Skyrme Model in the BPS Limit (C Adam, C Naya, J Sánchez-Guillén, R Vazquez and A Wereszczyński)Superqualitons: Baryons in Dense QCD (D K Hong)Condensed Matter:Rotational Symmetry Breaking in Baby Skyrme Models (M Karliner and I Hen)Emergent Gauge Fields and Their Nonperturbative Effects in Correlated Electrons (K-S Kim and A Tanaka)Spin and Isospin: Exotic Order in Quantum Hall Ferromanets (S M Girvin)Noncommutative Skyrmions in Quantum Hall Systems (Z F Ezawa and G Tsitsishvili)Meron-Pair Excitations in Bilayer Quantum Hall System (K Moon)Spin and Pseudospin Textures in Quantum Hall Systems (H A Fertig and L Brey)Half-Skyrmion Theory for High-Temperature Superconductivity (T Morinari)Deconfined Quantum Critical Points (T Senthil, A Vishwanath, L Balents, S Sachdev and M P A Fisher)Skyrmions in a Density-Wave State: A Mechanism for Chiral Superconductivity (S Chakravarty and C-H Hsu)String Theory:Skyrmion and String Theory (S Sugimoto)Holographic Baryons (P Yi)The Cheshire Cat Principle from Holography (H B Nielsen and I Zahed)Baryon Physics in a Five-Dimensional Model of Hadrons (A Pomarol and A Wulzer)Holographic Skyrmions (P M Sutcliffe)Holographic Baryons and Instanton Crystal (V Kaplunovsky, D Melnikov and J Sonnenschein) Readership: Research scientists in the fields of condensed matter physics, nuclear and particle physics, and string theory. '