Download or read book Theoretical Study on Correlation Effects in Topological Matter written by Hiroki Isobe and published by Springer. This book was released on 2017-04-04 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis elucidates electron correlation effects in topological matter whose electronic states hold nontrivial topological properties robust against small perturbations. In addition to a comprehensive introduction to topological matter, this thesis provides a new perspective on correlated topological matter. The book comprises three subjects, in which electron correlations in different forms are considered. The first focuses on Coulomb interactions for massless Dirac fermions. Using a perturbative approach, the author reveals emergent Lorentz invariance in a low-energy limit and discusses how to probe the Lorentz invariance experimentally. The second subject aims to show a principle for synthesizing topological insulators with common, light elements. The interplay between the spin–orbit interaction and electron correlation is considered, and Hund's rule and electron filling are consequently found to play a key role for a strong spin–orbit interaction important for topological insulators. The last subject is classification of topological crystalline insulators in the presence of electron correlation. Unlike non-interacting topological insulators, such two- and three-dimensional correlated insulators with mirror symmetry are demonstrated to be characterized, respectively, by the Z4 and Z8 group by using the bosonization technique and a geometrical consideration.
Download or read book Theoretical Studies of Correlation Effects in Graphene and Graphene Layers written by Jie Yuan and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Theoretical Studies of Correlation Effects in Graphene and Graphene Layers" by Jie, Yuan, 袁杰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: This thesis discusses correlation effects in graphene and bilayer graphene. The discovery of graphene was awarded 2010 Nobel Prize in Physics. Graphene is one of the most intriguing topics around the world. Its flexibilities make it a very promising material in device physics. From theoretical point of view, graphene connects condensed matter physics to quantum field theory, and is an excellent candidate for model studies. Furthermore, it stimulates researches in low-dimensional electron systems. Bilayer graphene is an interesting variant of graphene, and is one of the new directions in developing low-dimensional systems. Due to honeycomb lattice symmetry, the low-energy effective Hamiltonian of a graphene is described by gapless Dirac equation a(_σ DEGREES→).p round K(K DEGREES1) point. In this thesis, symmetry of Dirac equation is reviewed. In graphene, there are four copies of gapless Dirac equations. In addition, spin-orbit couplings are also discussed by using point-group techniques. We calculate screening and collective modes by using lattice Green's functions within random phase approximations. Some typical models on honeycomb lattice are reviewed, including Haldane model and Kane-Mele model. Interaction effects are further discussed within the Hubbard and extended models. It is reported there are some interesting phases both in doped and undoped cases. Graphene ribbons are also discussed in this thesis: zigzag ribbons and armchair ones. We investigate the attractive-U Kane-Mele-Hubbard model by using a mean-field theory, and find strong superconducting correlations along the edge, analogous to edge magnetism in positive U case. We investigate mesoscopic spin Hall effect on the surface of a three-dimensional topological insulator using McMillan Green's function techniques, and discuss the robustness of edge states and stabilities against interactions in topological insulator. Bilayer graphene is also investigated. Our study follows the recent experiments and theoretical proposals. As suggested by previous works, quantum spin Hall state and layer antiferromagnetic state are two most possible candidates of the ground state. We propose by tiny doping, a half-metallic state can be realized based on layer antiferromagnetic state. The responses to in-plane and perpendicular magnetic fields are also reviewed. DOI: 10.5353/th_b5089969 Subjects: Graphene
Download or read book Topological Matter written by Dario Bercioux and published by Springer. This book was released on 2018-10-03 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers basic and advanced aspects in the field of Topological Matter. The chapters are based on the lectures presented during the Topological Matter School 2017. It provides graduate level content introducing the basic concepts of the field, including an introductory session on group theory and topological classification of matter. Different topological phases such as Weyls semi-metals, Majoranas fermions and topological superconductivity are also covered. A review chapter on the major experimental achievements in the field is also provided. The book is suitable not only for master, graduate and young postdoctoral researchers, but also to senior scientists who want to acquaint themselves with the subject.
Download or read book Topological Systems Energy and Correlation written by Sayan Jana and published by . This book was released on 2023-04-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Topological Systems: Energy and Correlation" is a book that explores the intricate interplay between topology, energy, and correlation in various physical systems, particularly in the realm of quantum matter. The book delves into the fascinating phenomena arising from topological structures and the strong correlations among their constituent particles, such as zero-energy modes, non-trivial topology, and emergent excitations. It discusses the theoretical framework and experimental observations of topological phases of matter, such as topological insulators, superconductors, and semimetals, that exhibit robust and quantized electronic properties that are protected by symmetries and topology. The book is aimed at graduate students and researchers in condensed matter physics, materials science, and related fields who are interested in understanding the fundamental principles and exciting applications of topological systems.
Download or read book Energy and Water Development Appropriations for 2014 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2013 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 2013 Dept of Energy FY 2013 justifications written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2012 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 2013 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2012 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrons in Solids written by Hendrik Bluhm and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-04-01 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a continuation of classical condensed matter physics texts, this graduate textbook introduces advanced topics of correlated electron systems, mesoscopic transport,quantum computing, optical excitations and topological insulators. The book is focusing on an intuitive understanding of the basic concepts of these rather complex subjects.
Download or read book Condensed Matter Field Theory written by Alexander Altland and published by Cambridge University Press. This book was released on 2010-03-11 with total page 785 pages. Available in PDF, EPUB and Kindle. Book excerpt: This primer is aimed at elevating graduate students of condensed matter theory to a level where they can engage in independent research. Topics covered include second quantisation, path and functional field integration, mean-field theory and collective phenomena.
Download or read book Field Theories in Condensed Matter Physics written by Sumathi Rao and published by CRC Press. This book was released on 2019-04-24 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of field theoretic techniques to problems in condensed matter physics has generated an array of concepts and mathematical techniques to attack a range of problems such as the theory of quantum phase transitions, the quantum Hall effect, and quantum wires. While concepts such as the renormalization group, topology, and bosonization h
Download or read book Field Theories of Condensed Matter Physics written by Eduardo Fradkin and published by Cambridge University Press. This book was released on 2013-02-28 with total page 855 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the physics of the most challenging problems in condensed matter using the conceptual framework of quantum field theory, this book is of great interest to physicists in condensed matter and high energy and string theorists, as well as mathematicians. Revised and updated, this second edition features new chapters on the renormalization group, the Luttinger liquid, gauge theory, topological fluids, topological insulators and quantum entanglement. The book begins with the basic concepts and tools, developing them gradually to bring readers to the issues currently faced at the frontiers of research, such as topological phases of matter, quantum and classical critical phenomena, quantum Hall effects and superconductors. Other topics covered include one-dimensional strongly correlated systems, quantum ordered and disordered phases, topological structures in condensed matter and in field theory and fractional statistics.
Download or read book Strong Correlations and Topology in Novel Condensed Matter Platforms written by Ajesh Kumar and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a study of various phenomena in quantum condensed matter physics by focusing on their realization in promising novel highly-tunable experimental platforms. Chapters 2 − 4 focus on the design and theoretical study of different moiré material platforms that can simulate strongly correlated phenomena that have proved difficult to understand for many years. Chapter 2 proposes a transition metal dichalcogenide trilayer moiré heterostructure that can realize heavy-fermion quantum criticality, and is based on Ref. [113]. Chapter 3 describes low-energy collective modes of the correlated insulators in magic-angle twisted bilayer graphene and gives a simple physical interpretation of them. This is based on Ref. [115]. Chapter 4 proposes twisted bilayer graphene in a perpendicular magnetic field as a quantum simulator of non-Fermi liquid behavior, and is based on Ref. [111]. Chapter 5 focuses on realizing a Floquet symmetry protected topological phase in a superconducting qubit arrays and trapped ion quantum processors. It discusses ways to detect the topological phase, which are typically hidden to simple local probes, and is based on Ref. [112]. Chapter 6 (based on Ref. [114]) studies phase transitions involving quasiparticles whose motion is intrinsically constrained. Two-dimensional crystals provide a concrete realization of this problem and our results provide strong constraints on how these crystals can quantum melt. Finally, Chapter 7 discusses some open questions related to the material presented in this thesis
Download or read book Topological Phase Transitions and New Developments written by Jose Jorge V and published by World Scientific. This book was released on 2018-08-10 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geometry and topology have been a fascination in physics since the start of the 20th century. A leading example is Einstein's geometrical theory of gravity. At the beginning of the 1970s, topological ideas entered areas of condensed matter physics. These advances were driven by new seminal ideas resolving a serious contradiction between experiment and the standard interpretation of a rigorous mathematical theorem which led to the study of new exotic topological phases of matter. Topological defect driven phase transitions in thin, two dimensional films of superfluids, superconductors and crystals have provided great insight into the mechanism governing these topological phases present in those physical systems. Moreover, many of these topological properties remain 'protected' against disorder and topological distortion perturbations. An example of possible applications of such robustness to perturbations is in the search for encoding information in quantum computers, potentially providing the platform for fault-tolerant quantum computations. In the past four decades, the discovery of topological phases engendered great interest in condensed matter physics. It also attracted the attention of researchers working on quantum information, quantum materials and simulations, high energy physics and string theory. This unique volume contains articles written by some of the most prominent names in the field, including Nobel Laureate John Michael Kosterlitz and Professor Jorge V José. They originate from talks and discussions by leading experts at a recent workshop. They review previous works as well as addressing contemporary developments in the most pressing and important issues on various aspects of topological phases and topological phase transitions.
Download or read book Topological Insulators and Topological Superconductors written by B. Andrei Bernevig and published by Princeton University Press. This book was released on 2013-04-07 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate-level textbook is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for graduate students and researchers preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with simple concepts such as Berry phases, Dirac fermions, Hall conductance and its link to topology, and the Hofstadter problem of lattice electrons in a magnetic field. It moves on to explain topological phases of matter such as Chern insulators, two- and three-dimensional topological insulators, and Majorana p-wave wires. Additionally, the book covers zero modes on vortices in topological superconductors, time-reversal topological superconductors, and topological responses/field theory and topological indices. The book also analyzes recent topics in condensed matter theory and concludes by surveying active subfields of research such as insulators with point-group symmetries and the stability of topological semimetals. Problems at the end of each chapter offer opportunities to test knowledge and engage with frontier research issues. Topological Insulators and Topological Superconductors will provide graduate students and researchers with the physical understanding and mathematical tools needed to embark on research in this rapidly evolving field.
Download or read book Theoretical Study on Transport Properties of Topological States of Matter written by Hsiu-chuan Hsu and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In condensed matter physics, states of matter are usually classified by symmetry. Topological states of matter describe new quantum states of matter that cannot adiabatically connect to conventional states of matter even though they share the same symmetry. Thus, the discovery of topological states of matter has opened a new research era and attracted intensive research interests in recent years. This dissertation is devoted to the theoretical and numerical study of transport properties of topological states of matter, mainly focusing on two topological systems, time reversal invariant topological insulator nano-structures and the quantum anomalous Hall insulators.The first system studied in this dissertation is time reversal invariant topological insulator, which is an insulating material behaving as an insulator in its interior but with conducting channels on its surface. The conducting surface states of a topological insulator are known as "helical states" due to the spin texture in the momentum space and protected by time reversal symmetry. Helical surface states have been observed in surface sensitive experiments, such as angular-resolved photon emission spectroscopy and scanning tunneling microscopy. However, signatures of topological surface states in transport measurements are complicated by the dominating conduction from bulk channels and strong disorder effect. Therefore, in this dissertation, we numerically study transport in disordered topological insulator nano-structures, e.g. nanowires and nanotubes, which possess a larger surface- to-volume ratio compared to bulk systems. For a topological insulator nanowire, it is found that a gapless mode with linear dispersion, which is refered to as a topological state in the main text, arises when a half-integer magnetic flux quantum is inserted along the nanowire. We find that topological states possess a longer localization length than other non-topological states. Thus, for a long nanowire or nanotube, a larger conductance appears for half-integer magnetic flux, leading to magnetoconductance oscillations with a period equivalent to one magnetic flux quantum. Our numerical simulation of the magnetoconductance oscillations is supported by experimental observations in resistive Bi2Te3 nanotubes.Another system that we study is the quantum anomalous Hall insulator. Similar to the quantum Hall effect, the Hall conductance is quantized and the longitudinal resistance drops to zero in the quantum anomalous Hall effect. However, the quantum anomalous Hall effect is realized in a magnetic system in absence of external magnetic fields and the associated Landau levels. The quantum anomalous Hall effect was first proposed in magnetically doped HgTe quantum wells. However, one obstacle is that this system is paramagnetic, and thus external magnetic fields are required to polarize magnetization and inevitably leads to Landau levels. In this study, we focus on the role of in-plane magnetic fields and find that the quantum anomalous Hall effect can be realized by a purely in-plane magnetic field when there is strain in the system. Symmetry analysis is adopted to provide more theoretical insight of the underlying physics. Without any strain, we explore how to extract the role of magnetization in the standard transport measurement of Hall resistance by rotating magnetic fields. Our results provide a guidance to the recent experiments in Mn doped HgTe quatnum wells with rotating magnetic fields. Besides these studies, we also investigate anisotropic magneto-conductance in magnetically doped(Bi,Sb)2Te3 films.The studies in the dissertation are in a close collaboration with transportmeasurements of experimental groups, including magneto-conductance oscillation observed by Qi's group at Penn State and the study of the Hall conductance in Mn doped HgTe quantum wells with rotating magnetic fields by Molenkamp's group at Wuerzburg University.
Download or read book Formation and Interactions of Topological Defects written by Anne-Christine Davis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological defects have recently become of great interest in condensed matter physics, particle physics and cosmology. They are the unavoidable remnants of many symmetry breaking phase transitions. Topological defects can play an important role in describing the properties of many condensed matter systems (e.g. superfluids and superconduc tors); they can catalyze many unusual effects in particle physics models and they may be responsible for seeding the density perturbations in the early Universe which de velop into galaxies and the large-scale structure of the Universe. Topological defects are also of great interest in mathematics as nontrivial solutions of nonlinear differential equations stabilized by topological effects. The purpose of the Advanced Study Institute "Formation and Interactions of Topo logical Defects" was to bring together students and practitioners in condensed matter physics, particle physics and cosmology, to give a detailed exposition of the role of topo logical defects in these fields; to explore similarities and differences in the approaches; and to provide a common basis for discussion and future collaborative research on common problems.
Download or read book Quantum Theory of Condensed Matter written by Bertrand I. Halperin and published by World Scientific. This book was released on 2010 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ever since 1911, the Solvay Conferences have shaped modern physics. The 24th edition chaired by Bertrand Halperin did not break the tradition. Held in October 2008, it gathered in Brussels most of the leading figures working on the ?quantum theory of condensed matter?, addressing some of the most profound open problems in the field. The proceedings contain the ?rapporteur talks? giving a broad overview with unique insights by distinguished renowned scientists. These lectures cover the five sessions treating: mesoscopic and disordered systems; exotic phases and quantum phase transitions in model systems; experimentally realized correlated-electron materials; quantum Hall systems, and one-dimensional systems; systems of ultra-cold atoms, and advanced computational methods. In the Solvay tradition, the proceedings include also the prepared comments to the rapporteur talks. The discussions among the participants ? some of which are quite lively and involving dramatically divergent points of view ? have been carefully edited and reproduced in full.
