Diverse Quasiparticle Properties of Emerging Materials: First-Principles Simulations thoroughly explores the rich and unique quasiparticle properties of emergent materials through a VASP-based theoretical framework. Evaluations and analyses are conducted on the crystal symmetries, electronic energy spectra/wave functions, spatial charge densities, van Hove singularities, magnetic moments, spin configurations, optical absorption structures with/without excitonic effects, quantum transports, and atomic coherent oscillations. Key Features Illustrates various quasiparticle phenomena, mainly covering orbital hybridizations and spin-up/spin-down configurations Mainly focuses on electrons and holes, in which their methods and techniques could be generalized to other quasiparticles, such as phonons and photons Considers such emerging materials as zigzag nanotubes, nanoribbons, germanene, plumbene, bismuth chalcogenide insulators Includes a section on applications of these materials This book is aimed at professionals and researchers in materials science, physics, and physical chemistry, as well as upper-level students in these fields.
Diverse Quasiparticle Properties of Emerging Materials: First-Principles Simulations thoroughly explores the rich and unique quasiparticle properties of emergent materials through a VASP-based theoretical framework. Evaluations and analyses are conducted on the crystal symmetries, electronic energy spectra/wave functions, spatial charge densities, van Hove singularities, magnetic moments, spin configurations, optical absorption structures with/without excitonic effects, quantum transports, and atomic coherent oscillations. Key Features Illustrates various quasiparticle phenomena, mainly covering orbital hybridizations and spin-up/spin-down configurations Mainly focuses on electrons and holes, in which their methods and techniques could be generalized to other quasiparticles, such as phonons and photons Considers such emerging materials as zigzag nanotubes, nanoribbons, germanene, plumbene, bismuth chalcogenide insulators Includes a section on applications of these materials This book is aimed at professionals and researchers in materials science, physics, and physical chemistry, as well as upper-level students in these fields.
This book serves as a quick guide on the latest material systems including their synthesis, fabrication and characterization techniques. It discusses recent developments in different material systems and discusses their novel applications in various branches of science and engineering. The book briefs latest computational tools and techniques that are used to discover new material systems. The book also briefs applications of new emerging materials in various fields including, healthcare, sensors, opto-electronics, high power devices and nano-electronics. This book helps to create a synergy between computational and experimental research methods to better understand a particular material system.
This contributed volume presents chapters integrating experimental and computational advances in materials research and discusses how the potential release of emerging materials would impact the environment. With increasing populations, there is a growing pressure on resources and the environment to provide food, water, and energy. Innovative materials and novel technologies, such as nanocomposite and multifunctional materials, additive manufacturing, and remediation technologies, are constantly being developed to meet these demands. As technologies mature some potentially harmful materials will find their way into the environment. Depending on their environmental persistence, such as “forever chemicals” per- and polyfluoroalkyl substances (PFAS), some of the emerging materials may become a major environmental challenge. This book covers a broad spectrum of topics related to the recent advances and future directions in emerging materials research, molecular simulations, machine learning and QSAR approaches for environmental contaminants, advanced materials for water purification, remediation technologies of PFAS, and life-cycle assessment of materials. It offers an invaluable resource for postgraduate students and researchers in academia, industry, and different laboratories interested in the field.
Since the experimental isolation of graphene in 2004, there has been tremendous interest in studying quasi-two-dimensional (quasi-2D) systems. These atomically thin materials display a number of unique properties not found in their bulk counterparts, such as large self-energy and excitonic effects due to weaker screening in 2D. However, simple dimensionality arguments alone often fail to give quantitative - and sometimes qualitative - explanation of physical phenomena in these systems. Many low-energy excitation processes in these materials involve length scales comparable to the extent of these materials along the confined direction. Thus, many of these interesting properties are a result of the interplay of the physics of 2 and 3 dimensions. In order to predict quasiparticle and optical properties in these materials, it is therefore highly important to use methods that capture the explicit quasi-2D crystal structure and rely on as little experimental input as possible. Ab initio formalisms are well-tested, mature, and predictive methods for calculating physical properties of systems with arbitrary crystal structure and dimensionality. In particular, the ab initio GW and GW plus Bethe-Salpeter equation (BSE) approaches are reliable methods to compute quasiparticle and optical properties of materials without experimental parameters and for systems with arbitrary electronic structure and dimensionality. In this dissertation, we study the quasiparticle and optical properties of quasi-2D systems, with emphasis on graphene and monolayer transition metal dichalcogenides. This dissertation is divided into three parts. In the first part, we introduce the formalisms that allow us to compute quasiparticle and optical properties of material. We include a brief review of the quasiparticle approximation, and connect it to Green's function methods. We then introduce the GW approximation and the BSE as tools to compute quasiparticle and optical properties of materials, respectively. We include a simplified derivation of these two formalisms in terms of many-body perturbation theory and diagrammatic series. We also review how the GW approximation and the BSE are implemented into ab initio electronic-structure codes, such as BerkeleyGW. In the second part of the dissertation, we show our theoretical works on the quasiparticle and optical properties of quasi-2D systems. We compute the quasiparticle bandstructure, optical absorption spectrum, and excitonic series on monolayer MoS2, a prototypical quasi-2D semiconductor. We also understand the origin of novel physics in these materials, such as the presence of excitonic states that cannot be understood in terms of a 2D hydrogenic model. We understand these unique phenomena in terms of the unique features of the screening in 2D, and also show how this leads to severe challenges in applying the GW and GW-BSE approaches to system with reduced dimensionality. We then develop new methods that efficiently capture these fast variations of the screening, and reduce the computational cost of GW and GW-BSE approaches on these systems by orders of magnitude. Finally, in the third part of the dissertation, we show a variety of projects that are collabo- rations between our theoretical group at Berkeley and various experimental groups. In the first collaboration, we perform a joint work with Prof. Tony Heinz’s experimental group, wherein we demonstrate how excitonic effects on graphene can be tuned by carrier doping. Our work goes beyond the independent-particle picture, and includes, without adjustable parameters, the effect of finite quasiparticle lifetimes due to electron-electron and electron-phonon interactions on the optical absorption of graphene. The second project in this part - a collaboration with the experimental groups of Profs. Mike Crommie and Feng Wang - directly measures the exciton binding energy in MoSe2. Because these measurements are performed on a substrate of bilayer graphene, we develop a new method to include the effect of screening from the substrate into our ab initio formalism. Finally, the third joint theory-experiment work was a collaboration with Prof. Mike Crommie’s group, wherein we compute the quasiparticle properties of few-layer MoSe2 and simulate the corresponding scanning-tunneling spectroscopy curves. Our work shows how the electronic structure of MoSe2 evolves with layer number, and elucidates the role of layer hybridization, self-energy effects, and intrinsic/extrinsic screening in the quasiparticle properties of few-layer transition metal dichalcogenides.
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.
This book serves as a comprehensive treatment of the advanced microscopic properties of lithium- and sodium-based batteries. It focuses on the development of the quasiparticle framework and the successful syntheses of cathode/electrolyte/anode materials in these batteries. FEATURES Highlights lithium-ion and sodium-ion batteries as well as lithium sulfur-, aluminum-, and iron-related batteries Describes advanced battery materials and their fundamental properties Addresses challenges to improving battery performance Develops theoretical predictions and experimental observations under a unified quasiparticle framework Targets core issues such as stability and efficiencies Lithium-Related Batteries: Advances and Challenges will appeal to researchers and advanced students working in battery development, including those in the fields of materials, chemical, and energy engineering.
This issue of ECS Transactions addresses the fundamental material science, characterization, modeling and applications of Graphene, Ge-III-V and Emerging materials designed for alternatives technologies to replace CMOS.
Fundamental Physicochemical Properties of Germanene-related Materials: A Theoretical Perspective provides a comprehensive review of germanene-related materials to help users understand the essential properties of these compounds. The book covers various germanium complex states such as germanium oxides, germanium on Ag, germanium/silicon composites and germanium compounds. Diverse phenomena are clearly illustrated using the most outstanding candidates of the germanium/germanene-related material. Delicate simulations and analyses are thoroughly demonstrated under the first-principles method, being fully assisted by phenomenological models. Macroscopic phenomena in chemical systems, including their principles, practices and concepts of physics such as energy, structure, thermodynamics and quantum chemistry are fully covered. Germanium-based materials play critical roles in the basic and applied sciences, as clearly revealed in other group-IV and group-V condensed-matter systems. Their atomic configurations are suitable for creating the active chemical bonding among the identical and/or different nearest-neighboring atoms leading to diverse physical/chemical/material environments. Provides a comprehensive review of germanene-related materials with a physicochemical and theoretical foundation that is useful for readers in understanding the essential properties of these compounds Presents a unique theoretical framework under single and multi-hybridization theory Contains significant combinations with phenomenological and experimental measurements Focuses on the study of macroscopic phenomena in chemical systems in terms of their principles, practices and concepts of physics such as energy, structure, thermodynamics and quantum chemistry
