Dynamic Spin-Fluctuation Theory of Metallic Magnetism

Dynamic Spin-Fluctuation Theory of Metallic Magnetism

Author: Nikolai B. Melnikov

Publisher: Springer

Published: 2018-08-02

Total Pages: 284

ISBN-13: 3319929747

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This book presents a theoretical framework for magnetism in ferromagnetic metals and alloys at finite temperatures. The objective of the book is twofold. First, it gives a detailed presentation of the dynamic spin-fluctuation theory that takes into account both local and long-wave spin fluctuations with any frequency. The authors provide a detailed explanation of the fundamental role of quantum spin fluctuations in the mechanism of metallic magnetism and illustrate the theory with concrete examples. The second objective of the book is to give an accurate and self-contained presentation of many-body techniques such as the functional integral method and Green's functions, via a number of worked examples. These computational methods are of great use to solid state physicists working in a range of specialties. The book is intended primarily for researchers, but can also be used as textbook. The introductory chapters offer clear and complete derivations of the fundamentals, which makes the presentation self-contained. The main text is followed by a number of well-organized appendices that contain a detailed presentation of the necessary many-body techniques and computational methods. The book also includes a list of symbols and detailed index. This volume will be of interest to a wide range of physicists interested in magnetism and solid state physics in general, both theoreticians and experimentalists.


Modern Theory of Magnetism in Metals and Alloys

Modern Theory of Magnetism in Metals and Alloys

Author: Yoshiro Kakehashi

Publisher: Springer

Published: 2013-01-11

Total Pages: 345

ISBN-13: 9783642334023

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This book describes theoretical aspects of the metallic magnetism from metals to disordered alloys to amorphous alloys both at the ground state and at finite temperatures. The book gives an introduction to the metallic magnetism, and treats effects of electron correlations on magnetism, spin fluctuations in metallic magnetism, formation of complex magnetic structures, a variety of magnetism due to configurational disorder in alloys as well as a new magnetism caused by the structural disorder in amorphous alloys, especially the itinerant-electron spin glasses. The readers will find that all these topics can be understood systematically by means of the spin-fluctuation theories based on the functional integral method.


Spin Fluctuation Theory of Itinerant Electron Magnetism

Spin Fluctuation Theory of Itinerant Electron Magnetism

Author: Yoshinori Takahashi

Publisher: Springer

Published: 2013-04-09

Total Pages: 190

ISBN-13: 364236666X

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This volume shows how collective magnetic excitations determine most of the magnetic properties of itinerant electron magnets. Previous theories were mainly restricted to the Curie-Weiss law temperature dependence of magnetic susceptibilities. Based on the spin amplitude conservation idea including the zero-point fluctuation amplitude, this book shows that the entire temperature and magnetic field dependence of magnetization curves, even in the ground state, is determined by the effect of spin fluctuations. It also shows that the theoretical consequences are largely in agreement with many experimental observations. The readers will therefore gain a new comprehensive perspective of their unified understanding of itinerant electron magnetism.


Spin Fluctuations in Itinerant Electron Magnetism

Spin Fluctuations in Itinerant Electron Magnetism

Author: Toru Moriya

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 253

ISBN-13: 3642824994

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Ferromagnetism of metallic systems, especially those including transition metals, has been a controversial subject of modern science for a long time. This controversy sterns from the apparent dual character of the d-electrons responsible for magnetism in transition metals, i.e., they are itinerant elec trons described by band theory in their ground state, while at finite tem peratures they show various properties that have long been attributed to a system consisting of local magnetic moments. The most familiar example of these properties is the Curie-Weiss law of magnetic susceptibility obeyed by almost all ferromagnets above their Curie temperatures. At first the problem seemed to be centered around whether the d-elec trons themselves are localized or itinerant. This question was settled in the 1950s and early 1960s by various experimental investigations, in particular by observations of d-electron Fermi surfaces in ferromagnetic transition metals. These observations are generally consistent with the results of band calculations. Theoretical investigations since then have concentrated on explaining this dual character of d-electron systems, taking account of the effects of electron-electron correlations in the itinerant electron model. The problem in physical terms is to study the spin density fluctuati·ons, which are ne glected in the mean-field or one-electron theory, and their influence on the physical properties.


Magnetism and Magnetic Materials V

Magnetism and Magnetic Materials V

Author: Nikolai S. Perov

Publisher: Trans Tech Publications Ltd

Published: 2012-06-14

Total Pages: 620

ISBN-13: 3038138509

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These meetings of magnetologists have occurred every three years since the first symposium, held in 1999. During the past 12 years, MISM has grown, from being a local workshop, into the largest international conference on magnetism in Russia. The number of participants, and the scientific level of MISM, make it one of the most significant conferences worldwide. Volume is indexed by Thomson Reuters CPCI-S (WoS). The present papers are grouped into the chapters: Materials, Magnetism, Magnetic Materials, Spintronics and Magnetotransport, Soft and Hard Magnetic Materials, Multiferroics, Magnetostructural Transition-Related Effects, Magnetophotonics, Magnetism and Superconductivity, Magnetism of Nanostructures, Dilute Magnetic Semiconductors, High-Frequency Properties, Low-Dimensional Magnetism, Magnetic Soft Matter, Magnetic Oxides, Magnetism in Biology and Medicine. They constitute a very up-to-date and thorough coverage of the subject.


Modern Theory of Magnetism in Metals and Alloys

Modern Theory of Magnetism in Metals and Alloys

Author: Yoshiro Kakehashi

Publisher: Springer Science & Business Media

Published: 2013-01-11

Total Pages: 344

ISBN-13: 3642334016

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This book describes theoretical aspects of the metallic magnetism from metals to disordered alloys to amorphous alloys both at the ground state and at finite temperatures. The book gives an introduction to the metallic magnetism, and treats effects of electron correlations on magnetism, spin fluctuations in metallic magnetism, formation of complex magnetic structures, a variety of magnetism due to configurational disorder in alloys as well as a new magnetism caused by the structural disorder in amorphous alloys, especially the itinerant-electron spin glasses. The readers will find that all these topics can be understood systematically by means of the spin-fluctuation theories based on the functional integral method.


New Perspectives in Magnetism of Metals

New Perspectives in Magnetism of Metals

Author: Duk Joo Kim

Publisher: Springer Science & Business Media

Published: 2013-03-09

Total Pages: 470

ISBN-13: 1475730527

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The fundamental physics of metallic magnetism is not yet satisfactorily understood and continues to be interesting. For instance, although the detail is yet to be clarified, magnetism is anticipated to be playing a principal role in producing the high Tc superconductivity of the oxides. This book has two major objectives. First, it intends to provide an introduction to magnetism of metals in a broad sense. Besides pursuing the mechanism of metallic magnetism itself, it attempts to fmd and actively analyze magnetic causes hidden hitherto unnoticed behind various physical phenomena. My foremost goal is to expose the fundamental role played by phonons in the mechanism of metallic magnetism. I demonstrate how such a view also helps to elucidate a broad spectrum of other observations. The second objective is to concisely introduce the standard many-body points of view and techniques necessary in studying solid physics in general. The book is intended to be self-contained and starts with Chapter I containing a brief summary on the rudiments of quantum mechanics and statistical mechanics including the method of second quantization. In the same spirit, the foundation of magnetism in general is summarized in Chapter 2 and that for metals in particular, the Stoner theory, in Chapter 3. In Chapter 4, various linear responses of metallic electrons are systematically discussed with emphasis on the role of magnetism in them.


Magnetism

Magnetism

Author: L C Gupta

Publisher: World Scientific

Published: 1993-03-24

Total Pages: 462

ISBN-13: 9814505099

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Contents: Spin Fluctuations in Heisenberg Magnets: Dynamic Critical Phenomena and Excitations in Quasi-Periodic Systems (S W Lovesey)Quenching of Spin Fluctuations by High Magnetic Fields (K Ikeda et al.)Kondo Effect and Heavy Fermions (B Coqblin et al.)Magnetic Interactions in Correlated Electron Systems: High Pressure Investigations (J D Thompson)Hall Effect in Heavy Fermion and Mixed Valence Systems (A Hamzić & A Fert)Magnetic Properties of Uranium Based 1-2-2 Intermetallics (T Endstra et al.)Inelastic Magnetic Excitations in Anomalous Rare Earth Intermetallics (E Holland-Moritz)Neutron Scattering Studies of Magnetic Properties of Actinide Systems (G H Lander & G Aeppli)Magnetic Properties of Heavy Fermion Systems — As Studied by μSR-Spectroscopy (A Schenck)Re-Entrant Spin-Glasses: Do They Exist? (B R Coles & S B Roy)Insulating Spin Glass Systems (J K Srivastava)Nuclear Magnetism in Metals and Alloys (S Ramakrishnan & G Chandra) Readership: Solid-state physicists and chemists. keywords:


Renormalization Group Theory

Renormalization Group Theory

Author: Ulrich Köbler

Publisher: Springer Science & Business Media

Published: 2010-04-29

Total Pages: 402

ISBN-13: 3642024882

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Spin wave theory of magnetism and BCS theory of superconductivity are typical theories of the time before renormalization group (RG) theory. The two theories consider atomistic interactions only and ignore the energy degrees of freedom of the continuous (infinite) solid. Since the pioneering work of Kenneth G. Wilson (Nobel Prize of physics in 1982) we know that the continuous solid is characterized by a particular symmetry: invariance with respect to transformations of the length scale. Associated with this symmetry are particular field particles with characteristic excitation spectra. In diamagnetic solids these are the well known Debye bosons. This book reviews experimental work on solid state physics of the last five decades and shows in a phenomenological way that the dynamics of ordered magnets and conventional superconductors is controlled by the field particles of the infinite solid and not by magnons and Cooper pairs, respectively. In the case of ordered magnets the relevant field particles are called GSW bosons after Goldstone, Salam and Weinberg and in the case of superconductors the relevant field particles are called SC bosons. One can imagine these bosons as magnetic density waves or charge density waves, respectively. Crossover from atomistic exchange interactions to the excitations of the infinite solid occurs because the GSW bosons have generally lower excitation energies than the atomistic magnons. According to the principle of relevance the dynamics is governed by the excitations with the lowest energy. The non relevant atomistic interactions with higher energy are practically unimportant for the dynamics.


Local Probing of a Superconductor’s Quasiparticles and Bosonic Excitations with a Scanning Tunnelling Microscope

Local Probing of a Superconductor’s Quasiparticles and Bosonic Excitations with a Scanning Tunnelling Microscope

Author: Gozlinski, Thomas

Publisher: KIT Scientific Publishing

Published: 2023-03-24

Total Pages: 208

ISBN-13: 3731512793

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Complementary to scattering techniques, scanning tunnelling microscopy provides atomic-scale real space information about a material's electronic state of matter. State-of-the-art designs of a scanning tunnelling microscope (STM) allow measurements at millikelvin temperatures with unprecedented energy resolution. Therefore, this instrument excels in probing the superconducting state at low temperatures and especially its local quasiparticle excitations as well as bosonic degrees of freedom.