Magnetic Field Effects in Low-Dimensional Quantum Magnets

Magnetic Field Effects in Low-Dimensional Quantum Magnets PDF Author: Adam Iaizzi
Publisher: Springer
ISBN: 3030018032
Category : Science
Languages : en
Pages : 170

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Book Description
This thesis is a tour-de-force combination of analytic and computational results clarifying and resolving important questions about the nature of quantum phase transitions in one- and two-dimensional magnetic systems. The author presents a comprehensive study of a low-dimensional spin-half quantum antiferromagnet (the J-Q model) in the presence of a magnetic field in both one and two dimensions, demonstrating the causes of metamagnetism in such systems and providing direct evidence of fractionalized excitations near the deconfined quantum critical point. In addition to describing significant new research results, this thesis also provides the non-expert with a clear understanding of the nature and importance of computational physics and its role in condensed matter physics as well as the nature of phase transitions, both classical and quantum. It also contains an elegant and detailed but accessible summary of the methods used in the thesis—exact diagonalization, Monte Carlo, quantum Monte Carlo and the stochastic series expansion—that will serve as a valuable pedagogical introduction to students beginning in this field.

Magnetic Field Effects in Low-Dimensional Quantum Magnets

Magnetic Field Effects in Low-Dimensional Quantum Magnets PDF Author: Adam Iaizzi
Publisher: Springer
ISBN: 3030018032
Category : Science
Languages : en
Pages : 170

Get Book Here

Book Description
This thesis is a tour-de-force combination of analytic and computational results clarifying and resolving important questions about the nature of quantum phase transitions in one- and two-dimensional magnetic systems. The author presents a comprehensive study of a low-dimensional spin-half quantum antiferromagnet (the J-Q model) in the presence of a magnetic field in both one and two dimensions, demonstrating the causes of metamagnetism in such systems and providing direct evidence of fractionalized excitations near the deconfined quantum critical point. In addition to describing significant new research results, this thesis also provides the non-expert with a clear understanding of the nature and importance of computational physics and its role in condensed matter physics as well as the nature of phase transitions, both classical and quantum. It also contains an elegant and detailed but accessible summary of the methods used in the thesis—exact diagonalization, Monte Carlo, quantum Monte Carlo and the stochastic series expansion—that will serve as a valuable pedagogical introduction to students beginning in this field.

Low-Dimensional Magnetism

Low-Dimensional Magnetism PDF Author: A.N. Vasiliev
Publisher: CRC Press
ISBN: 1000527360
Category : Science
Languages : en
Pages : 274

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Book Description
Low-dimensional magnetism physics involves the search for new magnetic compounds and improving their characteristics to meet the needs of innovative technologies. A comprehensive overview of key materials, their formulation data and characteristics are detailed by the author. Key selling features: Explores dominant mechanisms of magnetic interaction to determine the parameters of exchange interactions in new magnetic materials. Describes how magnetism and superconductivity not only compete, but also "help" each other. Details characteristics of key materials in the magnetic subsystem. Results of several internationally renowned research groups are included and cited. Suitable for a wide range of readers in physics, materials science, and chemistry interested in the problems of the structure of matter.

Fundamentals of Low Dimensional Magnets

Fundamentals of Low Dimensional Magnets PDF Author: Ram K. Gupta
Publisher: CRC Press
ISBN: 1000640264
Category : Science
Languages : en
Pages : 480

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Book Description
A low-dimensional magnet is a key to the next generation of electronic devices. In some respects, low-dimensional magnets refer to nanomagnets (nanostructured magnets) or single-molecule magnets (molecular nanomagnets). They also include the group of magnetic nanoparticles, which have been widely used in biomedicine, technology, industries, and environmental remediation. Low-dimensional magnetic materials can be used effectively in the future in powerful computers (hard drives, magnetic random-access memory, ultra-low power consumption switches, etc.). The properties of these materials largely depend on the doping level, phase, defects, and morphology. This book covers various nanomagnets and magnetic materials. The basic concepts, various synthetic approaches, characterizations, and mathematical understanding of nanomaterials are provided. Some fundamental applications of 1D, 2D, and 3D materials are covered. This book provides the fundamentals of low-dimensional magnets along with synthesis, theories, structure-property relations, and applications of ferromagnetic nanomaterials. This book broadens our fundamental understanding of ferromagnetism and mechanisms for realization and advancement in devices with improved energy efficiency and high storage capacity.

Modern Theories of Many-Particle Systems in Condensed Matter Physics

Modern Theories of Many-Particle Systems in Condensed Matter Physics PDF Author: Daniel C. Cabra
Publisher: Springer Science & Business Media
ISBN: 3642104487
Category : Technology & Engineering
Languages : en
Pages : 380

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Book Description
Condensed matter systems where interactions are strong are inherently difficult to analyze theoretically. The situation is particularly interesting in low-dimensional systems, where quantum fluctuations play a crucial role. Here, the development of non-perturbative methods and the study of integrable field theory have facilitated the understanding of the behavior of many quasi one- and two-dimensional strongly correlated systems. In view of the same rapid development that has taken place for both experimental and numerical techniques, as well as the emergence of novel testing-grounds such as cold atoms or graphene, the current understanding of strongly correlated condensed matter systems differs quite considerably from standard textbook presentations. The present volume of lecture notes aims to fill this gap in the literature by providing a collection of authoritative tutorial reviews, covering such topics as quantum phase transitions of antiferromagnets and cuprate-based high-temperature superconductors, electronic liquid crystal phases, graphene physics, dynamical mean field theory applied to strongly correlated systems, transport through quantum dots, quantum information perspectives on many-body physics, frustrated magnetism, statistical mechanics of classical and quantum computational complexity, and integrable methods in statistical field theory. As both graduate-level text and authoritative reference on this topic, this book will benefit newcomers and more experienced researchers in this field alike.

Molecular Magnets

Molecular Magnets PDF Author: Maria Bałanda
Publisher: MDPI
ISBN: 3038977101
Category : Science
Languages : en
Pages : 166

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Book Description
Molecular magnets show many properties not met in conventional metallic magnetic materials, i.e. low density, transparency to electromagnetic radiation, sensitivity to external stimuli such as light, pressure, temperature, chemical modification or magnetic/electric fields, and others. They can serve as “functional” materials in sensors of different types or be applied in high-density magnetic storage or nanoscale devices. Research into molecule-based materials became more intense at the end of the 20th century and is now an important branch of modern science. The articles in this Special Issue, written by physicists and chemists, reflect the current work on molecular magnets being carried out in several research centers. Theoretical papers in the issue concern the influence of spin anisotropy in the low dimensional lattice of the resulting type of magnet, as well as thermodynamics and magnetic excitations in spin trimers. The impact of external pressure on structural and magnetic properties and its underlying mechanisms is described using the example of Prussian blue analogue data. The other functionality discussed is the magnetocaloric effect, investigated in coordination polymers and high spin clusters. In this issue, new molecular magnets are presented: (i) ferromagnetic high-spin [Mn6] single-molecule magnets, (ii) solvatomagnetic compounds changing their structure and magnetism dependent on water content, and (iii) a family of purely organic magnetic materials. Finally, an advanced calorimetric study of anisotropy in magnetic molecular superconductors is reviewed.

New Horizons in Low-Dimensional Electron Systems

New Horizons in Low-Dimensional Electron Systems PDF Author: H. Aoki
Publisher: Springer Science & Business Media
ISBN: 9401131902
Category : Science
Languages : en
Pages : 471

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Book Description
In Bird of Passage by Rudolf Peierls, we find a paragraph in which he de scribes his Cambridge days in the 1930s: On these [relativistic field theory] problems my main contacts were Dirac, and the younger theoreticians. These included in particular Nevill (now Sir Nevill) Mott, perhaps the friendliest among many kind and friendly people we met then. Professor Kamimura became associated with Sir Rudolf Peierls in the 1950s, when he translated, with his colleagues, Peierls's 1955 textbook, Quantum Theory of Solids, into Japanese. This edition, to which Sir Rudolf himself contributed a preface, benefitted early generations of Japanese solid state physicists. Later in 1974/5, during a sabbatical year spent at the Cavendish Laboratory, Professor Kamimura met and began a long association with Sir Nevill Mott. In particular, they developed ideas for disordered systems. One of the outcomes is a paper coauthored by them on ESR-induced variable range hopping in doped semiconductors. A series of works on disordered systems, together with those on two-dimensional systems, have served as building blocks for Physics of Interacting Electrons in Disordered Systems, in the International Series of Monographs on Physics, coauthored by Aoki and published in 1989 by the Oxford University Press. Soon after Professor Kamimura obtained a D. Sc. in 1959 for the work on the ligand field theory under the supervision ofMasao Kotani, his strong con nections in the international physical community began when he worked at the Bell Telephone Laboratories in 1961/64.

Frontiers in Condensed Matter Physics, Vol. 5

Frontiers in Condensed Matter Physics, Vol. 5 PDF Author:
Publisher: Allied Publishers
ISBN: 9788177647815
Category : Condensed matter
Languages : en
Pages : 332

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Book Description


Spectroscopy of Emerging Materials

Spectroscopy of Emerging Materials PDF Author: Eric C. Faulques
Publisher: Springer Science & Business Media
ISBN: 1402023960
Category : Science
Languages : en
Pages : 422

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Book Description
A comprehensive discussion of the key role of modern spectroscopic investigations in interdisciplinary materials science and engineering, covering emerging materials that are either absolutely novel or well-known materials with recently discovered, exciting properties. The types of spectroscopy discussed include optical, electronic and magnetic, UV-visible absorption, Rayleigh scattering, photoluminescence, vibrational, magnetic resonance, electron energy loss, EXAFS, XANES, optical tomography, time-resolved spectroscopy, and point contact spectroscopy. The materials studied are highly topical, with a focus on carbon and silicon nanomaterials including nanotubes, fullerenes, nanoclusters, metallic superconducting phases, molecular materials, magnetic and charge-stripe oxides, and biomaterials. Theoretical treatments are presented of molecular vibrational dynamics, vibration-induced decay of electronic excited states, nanoscale spin-orbit coupling in 2D Si-based structures, and the growth of semiconductor clusters.

Strong Interactions in Low Dimensions

Strong Interactions in Low Dimensions PDF Author: D. Baeriswyl
Publisher: Springer Science & Business Media
ISBN: 1402034636
Category : Science
Languages : en
Pages : 441

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Book Description
This book provides an attempt to convey the colorful facets of condensed matter systems with reduced dimensionality. Some of the specific features predicted for interacting one-dimensional electron systems, such as charge- and spin-density waves, have been observed in many quasi-one-dimensional materials. The two-dimensional world is even richer: besides d-wave superconductivity and the Quantum Hall Effect - perhaps the most spectacular phases explored during the last two decades - many collective charge and spin states have captured the interest of researchers, such as charge stripes or spontaneously generated circulating currents. Recent years have witnessed important progress in material preparation, measurement techniques and theoretical methods. Today larger and better samples, higher flux for neutron beams, advanced light sources, better resolution in electron spectroscopy, new computational algorithms, and the development of field-theoretical approaches allow an in-depth analysis of the complex many-body behaviour of low-dimensional materials. The epoch when simple mean-field arguments were sufficient for describing the gross features observed experimentally is definitely over. The Editors' aim is to thoroughly explain a number of selected topics: the application of dynamical probes, such as neutron scattering, optical absorption and photoemission, as well as transport studies, both electrical and thermal. Some of the more theoretical chapters are directly relevant for experiments, such as optical spectroscopy, transport in one-dimensional models, and the phenomenology of charge inhomogeneities in layered materials, while others discuss more general topics and methods, for example the concept of a Luttinger liquid and bosonization, or duality transformations, both promising tools for treating strongly interacting many-body systems.

Interacting Electrons and Quantum Magnetism

Interacting Electrons and Quantum Magnetism PDF Author: Assa Auerbach
Publisher: Springer Science & Business Media
ISBN: 1461208696
Category : Science
Languages : en
Pages : 249

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Book Description
In the excitement and rapid pace of developments, writing pedagogical texts has low priority for most researchers. However, in transforming my lecture l notes into this book, I found a personal benefit: the organization of what I understand in a (hopefully simple) logical sequence. Very little in this text is my original contribution. Most of the knowledge was collected from the research literature. Some was acquired by conversations with colleagues; a kind of physics oral tradition passed between disciples of a similar faith. For many years, diagramatic perturbation theory has been the major theoretical tool for treating interactions in metals, semiconductors, itiner ant magnets, and superconductors. It is in essence a weak coupling expan sion about free quasiparticles. Many experimental discoveries during the last decade, including heavy fermions, fractional quantum Hall effect, high temperature superconductivity, and quantum spin chains, are not readily accessible from the weak coupling point of view. Therefore, recent years have seen vigorous development of alternative, nonperturbative tools for handling strong electron-electron interactions. I concentrate on two basic paradigms of strongly interacting (or con strained) quantum systems: the Hubbard model and the Heisenberg model. These models are vehicles for fundamental concepts, such as effective Ha miltonians, variational ground states, spontaneous symmetry breaking, and quantum disorder. In addition, they are used as test grounds for various nonperturbative approximation schemes that have found applications in diverse areas of theoretical physics.