Electronic Properties of Rhombohedral Graphite


Book Description

This thesis presents the first systematic electron transport investigation of rhombohedral graphite (RG) films and thus lies at the interface of graphene physics, vdW heterostructure devices and topological matter. Electron transport investigation into the rhombohedral phase of graphite was limited to a few layers of graphene due to the competing hexagonal phase being more abundant. This work reports that in exfoliated natural graphite films, rhombohedral domains of up to 50 layers can be found. In the low energy limit, these domains behave as an N-layer generalisation of graphene. Moreover, being a potential alternative to twisted bilayer graphene systems, RG films show a spontaneous metal-insulator transition, with characteristic symmetry properties that could be described by mean-field theory where superconductivity is also predicted in these low energy bands. A nodal-line semimetal in the bulk limit, RG thin films are a 3D generalisation of the simplest topological insulator model: the Su-Schrieffer-Heeger chain. Similar to the more usual topological insulators, RG films exhibit parallel conduction of bulk states, which undergo three-dimensional quantum transport that reflects bulk topology.




Electronic Properties of Rhombohedral Graphite


Book Description

This thesis presents the first systematic electron transport investigation of rhombohedral graphite (RG) films and thus lies at the interface of graphene physics, vdW heterostructure devices and topological matter. Electron transport investigation into the rhombohedral phase of graphite was limited to a few layers of graphene due to the competing hexagonal phase being more abundant. This work reports that in exfoliated natural graphite films, rhombohedral domains of up to 50 layers can be found. In the low energy limit, these domains behave as an N-layer generalisation of graphene. Moreover, being a potential alternative to twisted bilayer graphene systems, RG films show a spontaneous metal-insulator transition, with characteristic symmetry properties that could be described by mean-field theory where superconductivity is also predicted in these low energy bands. A nodal-line semimetal in the bulk limit, RG thin films are a 3D generalisation of the simplest topological insulator model: the Su-Schrieffer-Heeger chain. Similar to the more usual topological insulators, RG films exhibit parallel conduction of bulk states, which undergo three-dimensional quantum transport that reflects bulk topology.




Electronic and Optical Properties of Graphite-Related Systems


Book Description

This book provides an overview of electronic and optical properties of graphite-related systems. It presents a well-developed and up-to-date theoretical model and addresses important advances in essential properties and diverse quantization phenomena. Key features include various Hamiltonian models, dimension-enriched carbon-related systems, complete and unusual results, detailed comparisons with the experimental measurements, clear physical pictures, and further generalizations to other emergent 2D materials. It also covers potential applications, such as touch-screen panel devices, FETs, supercapacitors, sensors, LEDs, solar cells, photodetectors, and photomodulators.




Chemical Modifications Of Graphene-like Materials


Book Description

Graphene-like materials have attracted considerable interest in the fields of condensed-matter physics, chemistry, and materials science due to their interesting properties as well as the promise of a broad range of applications in energy storage, electronic, optoelectronic, and photonic devices.The contents present the diverse phenomena under development in the grand quasiparticle framework through the first-principles calculations. The critical mechanisms, the orbital hybridizations and spin configurations of graphene-like materials through the chemical adsorptions, intercalations, substitutions, decorations, and heterojunctions, are taken into account. Specifically, the hydrogen-, oxygen-, transition-metal- and rare-earth-dependent compounds are thoroughly explored for the unusual spin distributions. The developed theoretical framework yields concise physical, chemical, and material pictures. The delicate evaluations are thoroughly conducted on the optimal lattices, the atom- and spin-dominated energy bands, the orbital-dependent sub-envelope functions, the spatial charge distributions, the atom- orbital- and spin-projected density of states, the spin densities, the magnetic moments, and the rich optical excitations. All consistent quantities are successfully identified by the multi-orbital hybridizations in various chemical bonds and guest- and host-induced spin configurations.The scope of the book is sufficiently broad and deep in terms of the geometric, electronic, magnetic, and optical properties of 3D, 2D, 1D, and 0D graphene-like materials with different kinds of chemical modifications. How to evaluate and analyze the first-principles results is discussed in detail. The development of the theoretical framework, which can present the diversified physical, chemical, and material phenomena, is obviously illustrated for each unusual condensed-matter system. To achieve concise physical and chemical pictures, the direct and close combinations of the numerical simulations and the phenomenological models are made frequently available via thorough discussions. It provides an obvious strategy for the theoretical framework, very useful for science and engineering communities.




Introduction to Graphene-Based Nanomaterials


Book Description

Graphene is one of the most intensively studied materials, and has unusual electrical, mechanical and thermal properties, which provide almost unlimited potential applications. This book provides an introduction to the electrical and transport properties of graphene and other two-dimensional nanomaterials, covering ab-initio to multiscale methods. Updated from the first edition, the authors have added chapters on other two-dimensional materials, spin-related phenomena, and an improved overview of Berry phase effects. Other topics include powerful order N electronic structure, transport calculations, and ac transport and multiscale transport methodologies. Chapters are complemented with concrete examples and case studies, questions and exercises, detailed appendices and computational codes. It is a valuable resource for graduate students and researchers working in physics, materials science or engineering who are interested in the field of graphene-based nanomaterials.




Diverse Quantization Phenomena in Layered Materials


Book Description

This monograph offers a comprehensive overview of diverse quantization phenomena in layered materials, covering current mainstream experimental and theoretical research studies, and presenting essential properties of layered materials along with a wealth of figures. This book illustrates commonly used synthesis methods of these 2D materials and compares the calculated results and experimental measurements, including novel features not yet reported. The book also discusses experimental measurements of magnetic quantization, theoretical modeling for studying systems and covers diversified magneto-electronic properties, magneto-optical selection rules, unusual quantum Hall conductivities, and single- and many-particle magneto-Coulomb excitations. Rich and unique behaviors are clearly revealed in few-layer graphene systems with distinct stacking configuration, stacking-modulated structures, silicon-doped lattices, bilayer silicene/germanene systems with the bottom-top and bottom-bottom buckling structures, monolayer and bilayer phosphorene systems, and quantum topological insulators. The generalized tight-binding model, the static and dynamic Kubo formulas, and the random-phase approximation are developed/modified to thoroughly explore the fundamental properties and propose the concise physical pictures. Different high-resolution experimental measurements are discussed in detail, and they are consistent with the theoretical predictions. Aimed at readers working in materials science, physics, and engineering this book should be useful for potential applications in energy storage, electronic devices, and optoelectronic devices.




Geometric and Electronic Properties of Graphene-Related Systems


Book Description

Due to its physical, chemical, and material properties, graphene has been widely studied both theoretically and experimentally since it was first synthesized in 2004. This book explores in detail the most up-to-date research in graphene-related systems, including few-layer graphene, sliding bilayer graphene, rippled graphene, carbon nanotubes, and adatom-doped graphene, among others. It focuses on the structure-, stacking-, layer-, orbital-, spin- and adatom-dependent essential properties, in which single- and multi-orbital chemical bondings can account for diverse phenomena. Geometric and Electronic Properties of Graphene-Related Systems: Chemical Bonding Schemes is excellent for graduate students and researchers, but understandable to undergraduates. The detailed theoretical framework developed in this book can be used in the future characterization of emergent materials.




Semimetals


Book Description




Coulomb Excitations and Decays in Graphene-Related Systems


Book Description

Coulomb Excitations and Decays in Graphene-Related Systems provides an overview of the subject under the effects of lattice symmetries, layer numbers, dimensions, stacking configurations, orbital hybridizations, intralayer and interlayer hopping integrals, spin-orbital couplings, temperatures, electron/hole dopings, electric field, and magnetic quantization while presenting a new theoretical framework of the electronic properties and the electron-electron interactions together. This book presents a well-developed theoretical model and addresses important advances in essential properties and diverse excitation phenomena. Covering plenty of critical factors related to the field, the book also addresses the theoretical model which is applicable to various dimension-enriched graphene-related systems and other 2D materials, including layered graphenes, graphites, carbon nanotubes, silicene, and germanene. The text is aimed at professionals in materials science, physics, physical chemistry, and upper level students in these fields.




Rich Quasiparticle Properties In Layered Graphene-related Systems


Book Description

This comprehensive book delves into the fascinating world of quasiparticle properties of graphene-related materials. The authors thoroughly explore the intricate effects of intrinsic and extrinsic interactions on the material's properties, while unifying the single-particle and many-particle properties through the development of a theoretical framework. The book covers a wide range of research topics, including long-range Coulomb interactions, dynamic charge density waves, Friedel oscillations and plasmon excitations, as well as optical reflection and transmission spectra of thin films. Also it highlights the crucial roles of inelastic Coulomb scattering and optical scattering in the quasiparticle properties of layered systems, and the impact of crystal symmetry, number of layers, and stacking configuration on their uniqueness. Furthermore, the authors explore the topological properties of quasiparticles, including 2D time-reversal-symmetry protected topological insulators with quantum spin Hall effect, and rhombohedral graphite with Dirac nodal lines. Meanwhile, the book examines the gate potential application for creating topological localized states and shows topological invariants of 2D Dirac fermions, and binary Z2 topological invariants under chiral symmetry. The calculated results are consistent with the present experimental observations, establishing it as a valuable resource for individuals interested in the quasiparticle properties of novel materials.