Download or read book Electronic Properties Of Dirac And Weyl Semimetals written by Eduard V Gorbar and published by World Scientific. This book was released on 2021-01-04 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph reviews various aspects of electronic properties of Dirac and Weyl semimetals. After a brief discussion of 2D Dirac semimetals, a comprehensive review of 3D materials is given. The description starts from an overview of the topological properties and symmetries of Dirac and Weyl semimetals. In addition, several low-energy models of Dirac and Weyl quasiparticles are presented. The key ab initio approaches and material realizations are given. The monograph includes detailed discussions of the surface Fermi arcs, anomalous transport properties, and collective modes of Dirac and Weyl semimetals. Superconductivity in these materials is briefly addressed.

Download or read book Dirac and Weyl Semimetals for Novel Device Applications written by Niraj Bhattarai and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much fundamental research in condensed matter physics has been driven by the tremendous influence of high-energy physics. In 1928, Paul Dirac laid a strong foundation in the unification of quantum mechanics and relativistic physics in explaining the nature of the electron. The key idea of Dirac's equation was to describe relativistic particles like Dirac and Weyl fermions in high-energy physics. After the discovery of topological insulators (ordinary insulators in the bulk state but allowing charge to flow on their surfaces) in the early 1980s, the search for new topological semimetals such as Dirac and Weyl mushroomed over the recent decades in condensed matter physics. Dirac and Weyl semimetals host Dirac and Weyl fermions respectively in the form of low-energy excitations and are characterized by band-touching points with linear dispersion similar to massless relativistic particles predicted in high-energy physics.The smallest feature size of current silicon-based advanced microelectronic devices is around 4 nm and the rate of development of current microelectronics has slowed down as silicon appears to have reached its physical limit. Industries are looking for alternatives to silicon-based technology. The discovery of Dirac and Weyl semimetals paves the way for developing new forms of microelectronics. These materials offer nearly dissipationless current and that could dramatically speed up the performance and efficiency of modern electronic devices. Weyl semimetals are also known for exhibiting exotic low energy physics such as Fermi arcs on the surface, distinct magneto-transport properties, and chiral anomaly-induced quantum transport. Such exotic properties of Weyl semimetals are useful for making new types of electronic devices such as broadband photodetectors, light-emitting diodes, biosensors, and superfast quantum computers capable of parsing multi-state superposition. While the promise of Dirac and Weyl semimetal is clear, the practical integration of such systems into everyday devices depends on a thorough understanding of the materials at the nanoscale. In my dissertation research, I have grown nanofilms of three different systems - LaAlGe, MoTe2, and FeSn, of which the former two are examples of Weyl semimetal and later is a Dirac semimetal. For the first time, high-quality thin films for LaAlGe and FeSn have been grown using the ultra-high vacuum molecular beam epitaxy method. I have shown that these systems can be grown on silicon substrates, which can be directly used for multifunctional device applications. I have systematically investigated the electrical transport and magneto-transport properties of these systems to understand the underlying physics, especially non-saturating magnetoresistance due to perfect electron and hole carrier balance up to a very high magnetic field. Not only are these new systems extremely important for our understanding of fundamental quantum phenomena, but also, they exhibit completely different transport phenomena from ordinary materials. Dirac semimetals also exhibit non-saturating extremely large magnetoresistance as a consequence of their robust electronic bands being protected by time-reversal symmetry. These open undeniably new possibilities for materials engineering and applications including quantum computing.

Download or read book Electronic Band Structure Engineering and Ultrafast Dynamics of Dirac Semimetals written by Changhua Bao and published by Springer Nature. This book was released on with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Topological Insulators written by Shun-Qing Shen and published by Springer Science & Business Media. This book was released on 2013-01-11 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological insulators are insulating in the bulk, but process metallic states present around its boundary owing to the topological origin of the band structure. The metallic edge or surface states are immune to weak disorder or impurities, and robust against the deformation of the system geometry. This book, the first of its kind on topological insulators, presents a unified description of topological insulators from one to three dimensions based on the modified Dirac equation. A series of solutions of the bound states near the boundary are derived, and the existing conditions of these solutions are described. Topological invariants and their applications to a variety of systems from one-dimensional polyacetalene, to two-dimensional quantum spin Hall effect and p-wave superconductors, and three-dimensional topological insulators and superconductors or superfluids are introduced, helping readers to better understand this fascinating new field. This book is intended for researchers and graduate students working in the field of topological insulators and related areas. Shun-Qing Shen is a Professor at the Department of Physics, the University of Hong Kong, China.

Download or read book Topological Semimetals written by David J. Fisher and published by Materials Research Forum LLC. This book was released on 2019-04-20 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological semimetals are quantum materials that are not only extremely interesting from a theoretical point of view but also have a great potential for technological applications in which superconducting, semiconducting and other semimetal behaviors are involved. Keywords: Quantum Materials, Macroscopic Quantum Phenomena, Topological Semimetals, Dirac Semimetals, Weyl Semimetals, Nodal-Line Semimetals, Antimony and Antimonides, Antimonene, Arsenides, Bismuthides, Boron, Borides, Borophene, Carbon and Carbides, Chalcogenides, Nitrides, Phosphorus, Phosphides, Silicides, Topological Metals, Topological States of Matter.

Download or read book Linear Electrodynamic Response of Topological Semimetals written by Artem V. Pronin and published by Springer Nature. This book was released on 2023-08-17 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a model description for the electromagnetic response of topological nodal semimetals and summarizes recent experimental findings in these systems. Specifically, it discusses various types of topological semimetals – Dirac, Weyl, nodal-line, triple-point, and multifold semimetals – and provides description for the characteristic features of the linear electrodynamic response for all these types of materials. Topological semimetals possess peculiar bulk electronic band structure, which leads to unusual electrodynamic response. For example, the low-energy inter-band optical conductivity of nodal semimetals is supposed to demonstrate power-law frequency dependence and the intra- and inter-band contributions to the conductivity are often mixed. Further, the magneto-optical response is also unusual, because of the non-equidistant spacing between the Landau levels. Finally, in semimetals with chiral electronic bands, e.g. in Weyl semimetals, the simultaneous application of parallel magnetic and electric fields leads to the chiral anomaly, i.e. to a misbalance between the electrons with diffident chiralities. This misbalance affects the electrodynamics properties of the material and can be detected optically. All these points are addressed here in detail. The book is written for a wide audience of physicists, working in the field of topological condensed matter physics. It gives a pedagogical introduction enabling graduate students and non-experts to familiarize themselves with the subject.

Download or read book Optical and Electrical Properties of Nanoscale Materials written by Alain Diebold and published by Springer Nature. This book was released on 2022-01-10 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the optical and electrical properties of nanoscale materials with an emphasis on how new and unique material properties result from the special nature of their electronic band structure. Beginning with a review of the optical and solid state physics needed for understanding optical and electrical properties, the book then introduces the electronic band structure of solids and discusses the effect of spin orbit coupling on the valence band, which is critical for understanding the optical properties of most nanoscale materials. Excitonic effects and excitons are also presented along with their effect on optical absorption. 2D materials, such as graphene and transition metal dichalcogenides, are host to unique electrical properties resulting from the electronic band structure. This book devotes significant attention to the optical and electrical properties of 2D and topological materials with an emphasis on optical measurements, electrical characterization of carrier transport, and a discussion of the electronic band structures using a tight binding approach. This book succinctly compiles useful fundamental and practical information from one of the fastest growing research topics in materials science and is thus an essential compendium for both students and researchers in this rapidly moving field.

Download or read book Peter Suranyi 87th Birthday Festschrift A Life In Quantum Field Theory written by Philip C Argyres and published by World Scientific. This book was released on 2022-10-25 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a Festschrift compiled in honor of Professor Peter Suranyi, Professor Emeritus, University of Cincinnati. In a long career spanning almost 60 years, Professor Suranyi has made valuable contributions in many areas of theoretical physics, especially in the fields of strong interaction physics, quantum field theory, particle physics, statistical mechanics, lattice field theory, condensed matter physics, and particle cosmology. His important contributions range from analysis of Regge poles in quantum field theory, work on Reggeon field theory, developing improved perturbation theory methods and numerical simulation techniques, analyzing rigidity percolation and molecular clustering in network glasses, to his recent work on Bose condensate dark matter. This volume is our way of paying tribute to his scientific achievements, mentoring prowess, and his rigorous outlook on theoretical physics.

Download or read book Electronic and Transport Properties of Weyl Semimetals written by Timothy M. McCormick and published by . This book was released on 2018 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Weyl semimetals possess low energy excitations which act as monopoles of Berry curvature in momentum space. These emergent monopoles are at the heart of the extensive novel transport properties that Weyl semimetals exhibit. We show how the Nernst effect, combining entropy with charge transport, gives a unique signature for the presence of Dirac bands. The Nernst thermopower of NbP (maximum of 800 $\mu \textrm{V}\cdot \textrm{K}^{-1}$ at 9 T, 109 K) exceeds its conventional thermopower by a hundredfold and is significantly larger than the thermopower of traditional thermoelectric materials. The Nernst effect has a pronounced maximum near $T_M=90 \pm 20 \textrm{K}=\mu_{0}/ \kb$ ($\mu_0$ is chemical potential at $T=0$ K). A self-consistent theory without adjustable parameters shows that this results from electrochemical potential pinning to the Weyl point energy at $T\geq T_M$, driven by charge neutrality and Dirac band symmetry.

Download or read book The Universe in a Helium Droplet written by G. E. Volovik and published by Oxford University Press on Demand. This book was released on 2003-03-06 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents a general overview of analogies between phenomena in condensed matter physics and quantum field theory and elementary particle physics.

Download or read book Photoelectron Spectroscopy written by Stefan Hüfner and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date introduction to the field, treating in depth the electronic structures of atoms, molecules, solids and surfaces, together with brief descriptions of inverse photoemission, spin-polarized photoemission and photoelectron diffraction. Experimental aspects are considered throughout and the results carefully interpreted by theory. A wealth of measured data is presented in tabullar for easy use by experimentalists.

Download or read book Topological Phases of Matter written by Roderich Moessner and published by Cambridge University Press. This book was released on 2021-04-29 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological Phases of Matter are an exceptionally dynamic field of research: several of the most exciting recent experimental discoveries and conceptual advances in modern physics have originated in this field. These have generated new, topological, notions of order, interactions and excitations. This text provides an accessible, unified and comprehensive introduction to the phenomena surrounding topological matter, with detailed expositions of the underlying theoretical tools and conceptual framework, alongside accounts of the central experimental breakthroughs. Among the systems covered are topological insulators, magnets, semimetals, and superconductors. The emergence of new particles with remarkable properties such as fractional charge and statistics is discussed alongside possible applications such as fault-tolerant topological quantum computing. Suitable as a textbook for graduate or advanced undergraduate students, or as a reference for more experienced researchers, the book assumes little prior background, providing self-contained introductions to topics as varied as phase transitions, superconductivity, and localisation.

Download or read book Electronic and Magnetic Properties of MBE Grown Topological Semimetals written by Timothy Pillsbury and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring and expanding the menagerie of topological materials has been at the forefront of condensed matter physics for over a decade. With the discovery of each new class of materials, starting with graphene, followed by topological insulators, and continuing most recently into topological semimetals, new paradigms have been discovered that provide a platform for exploring fundamental physics as well as novel practical applications. Crucial to all these innovations has been the topologically protected edge and surface states, which in addition to their robust nature, also have strong spin or valley correlation with momentum, offering direct coupling of macroscopic electronic properties to the quantum state of electrons. The interaction between magnetism and topology has lead to novel quantum phenomena, such as the quantum anomalous Hall effect, as well as enhanced device capabilities, such as the switching of magnetic polarization via the topological surface states. In topological semimetals, it is predicted that magnetism creates a transition from a Dirac to a Weyl semimetal phase by breaking time-reversal symmetry. Experimentally realizing such a transition will provide a fundamental platform for examining the emergence of Weyl fermions, as well as a practical platform for engineering tailored Weyl semimetals, including the ideal case of two Weyl nodes which has yet to be discovered in any intrinsic Weyl semimetal. The material system explored most extensively throughout this dissertation is the transition metal dichalcogenide Dirac semimetal ZrTe2. Thus far, a few thin film studies have demonstrated the existence of a Dirac semimetal phase in this material directly through angle resolved photoemission spectroscopy (ARPES) analysis of the Dirac cone as well as through transport measurements of the chiral anomaly. Additionally, a very recent experiment demonstrates the existence of a superconducting phase in ZrTe2 that could lead to further interest if it is shown to coexist with the Dirac semimetal phase. To facilitate further research into this promising material platform, the first portion of this dissertation focuses on the the development of high quality ZrTe2 thin films on insulating substrates. This is a necessary step for characterizing the electronic states of the material as well as adapting it for spintronics. Through transmission electron microscopy, scanning tunneling microscopy, and x-ray diffraction, the lattice structure and quality are assessed. ARPES and transport measurements demonstrate hole-like carriers. While this matches theoretical predictions for this material, it is at odds with most of the current literature, which demonstrates n-type carriers due to the high defect density. To observe the Dirac cone, tellurium vacancies are intentionally introduced for ARPES measurements, although this method was not effective for transport measurements. Ultimately, this prevents the observation of many of the desirable transport phenomena expected of a Dirac semimetal. Finally, we report the presence of weak anti-localization in ZrTe2 thin films at low temperatures. After establishing the MBE growth of ZrTe2 thin films, chromium dopants are introduced into these films to form (CrxZr1-x)Te2. Structural characterization is consistent with a transition between the Dirac semimetal ZrTe2 and the recently discovered metallic 2D ferromagnet CrTe2. This makes it phenomenologically distinct from a recently reported Cr-intercalated ZrTe2, which did not demonstrate similar changes in lattice structure and demonstrates completely different ARPES and transport phenomena. The (CrxZr1-x)Te2 thin films presented in this work are demonstrated to be ferromagnetic, with a TC of ∼150 K, as revealed via the anomalous Hall effect as well as magnetometry measurements. This system could be a critical component for realizing the transition from a Dirac to a Weyl semimetal, although currently it is limited by the location of the Fermi level. Finally, the next steps to utilizing the Dirac semimetal ZrTe2 in real devices are presented. Additionally, other methods of inducing magnetism based on the foundation laid by the study of (CrxZr1-x)Te2 are explored, such as magnetic proximity effect and alternative dopants. Ultimately, this research presents an approach towards tailoring magnetism in topological semimetals that has important implications for examining the transition between Dirac and Weyl semimetals through time-reversal symmetry breaking as well as for designing functional materials for spintronics applications.

Download or read book Chiral Matter Proceedings Of The Nobel Symposium 167 written by Egor Babaev and published by World Scientific. This book was released on 2023-02-13 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: A geometric figure has chirality, or handedness, if its mirror image cannot be brought to coincide with itself. The concept of chirality was instrumental in establishing the tetrahedral valences of the carbon atom, and has continued to play a key role in chemistry and molecular biology ever since.The fact that living organisms use only one of two mirror isomers of such molecules as amino acids and sugars, that is, the question of the origin of homochirality of the molecular basis of life, remains an unsolved problem of the same dignity as the origin of dark matter and dark energy.The increasing importance of chirality and topology in condensed matter physics and chemistry, and the production of new states of matter in heavy-ion collisions, have brought the concept of chirality into physics and cosmology in a tangible way while at the same time expanded the physics/chemistry interface. The book is the first to address all aspects of chirality in a single volume.

Download or read book Electronic Properties of Rhombohedral Graphite written by Servet Ozdemir and published by Springer Nature. This book was released on 2021-10-25 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Emerging Materials written by Laxman Raju Thoutam and published by Springer Nature. This book was released on 2022-05-13 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book The k p Method written by Lok C. Lew Yan Voon and published by Springer Science & Business Media. This book was released on 2009-06-06 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: I ?rst heard of k·p in a course on semiconductor physics taught by my thesis adviser William Paul at Harvard in the fall of 1956. He presented the k·p Hamiltonian as a semiempirical theoretical tool which had become rather useful for the interpre- tion of the cyclotron resonance experiments, as reported by Dresselhaus, Kip and Kittel. This perturbation technique had already been succinctly discussed by Sho- ley in a now almost forgotten 1950 Physical Review publication. In 1958 Harvey Brooks, who had returned to Harvard as Dean of the Division of Engineering and Applied Physics in which I was enrolled, gave a lecture on the capabilities of the k·p technique to predict and ?t non-parabolicities of band extrema in semiconductors. He had just visited the General Electric Labs in Schenectady and had discussed with Evan Kane the latter’s recent work on the non-parabolicity of band extrema in semiconductors, in particular InSb. I was very impressed by Dean Brooks’s talk as an application of quantum mechanics to current real world problems. During my thesis work I had performed a number of optical measurements which were asking for theoretical interpretation, among them the dependence of effective masses of semiconductors on temperature and carrier concentration. Although my theoretical ability was rather limited, with the help of Paul and Brooks I was able to realize the capabilities of the k·p method for interpreting my data in a simple way.