Download or read book Investigation of Light induced Ultrafast Magnetization Dynamics Using Ab Initio Methods written by Philippe Scheid and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis begins with a review of the current experimental and theoretical state of the art related to the light-induced ultrafast demagnetization and the all-optical helicity-dependent switching. This is followed by an overview of density functional theory, upon which relies most of the work reported thereafter. The first set of results concerns the ab initio study of the effect of a rise in the electronic temperature on the magnetized matter properties, and more specifically Fe, Co, Ni and FePt. We show that the magnetic moment carried by each atom disappears at the so-called Stoner temperature, and that this phenomenon impacts the electronic energy and specific heat, even at low electronic temperature. Then, we show that upon an increase in the electronic temperature, the interatomic Heisenberg exchange, which is responsible for the magnetic ordering, decreases. Using the atomistic Langevin Landau-Lifshitz-Gilbert equation, we demonstrate that this decrease is enough to induce a large reduction of the average magnetization by creating transversal excitations. The second set of results regards the origin of the helicity-dependent light-induced dynamics. While the literature attributes it mainly to the inverse Faraday effect, we argue that another and novel phenomenon, which occurs during the absorption of the light, may be more suited to account for the experimental dynamics. Indeed, using the Fermi golden rule and ground state density functional theory calculations in Fe, Co, Ni and FePt, we show that, as the light is absorbed and electrons are excited, concurrently to the increase of the electronic energy, the spin-state is also changed in presence of spin-orbit coupling. This results in a difference in the value of the atomic magnetic moments, persisting even after the light is gone, as opposed to the inverse Faraday effect. Then, using real-time time-dependent density functional theory, we compute the magnetization dynamics induced by real optical and XUV femtosecond circularly polarized pulses. We show that, in both cases the dynamics is helicity-dependent and that this characteristic is largely amplified in the XUV regime involving the semi-core 3p states. Finally, we compare the relative role of the inverse Faraday effect and the magnetization induced during the absorption of the light and show that the latter plays a prominent role, especially after the light has gone, and in the XUV regime.
Download or read book Introduction to Ultrafast Phenomena written by Guo-ping Zhang and published by CRC Press. This book was released on 2020-12-08 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, the first of this kind, provides a comprehensive introduction to ultrafast phenomena, covering the fundamentals of ultrafast spin and charge dynamics, femtosecond magnetism, all-optical spin switching, and high-harmonic generation. It covers the experimental tools, including ultrafast pump-probe experiments, and theoretical methods including quantum chemistry and density functional theory, both time-independent and time-dependent. The authors explain in clear language how an ultrafast laser pulse is generated experimentally, how it can induce rapid responses in electrons and spins in molecules, nanostructures and solids (magnetic materials and superconductors), and how it can create high-harmonic generation from atoms and solids on the attosecond timescale. They also show how this field is driving the next generation of magnetic storage devices through femtomagnetism, all-optical spin switching in ferrimagnets and beyond, magnetic logic in magnetic molecules, and ultrafast intense light sources, incorporating numerous computer programs, examples, and problems throughout, to show how the beautiful research can be done behind the scene. Key features: · Provides a clear introduction to modern ultrafast phenomena and their applications in physics, chemistry, materials sciences, and engineering. · Presents in detail how high-harmonic generation occurs in atoms and solids. · Explains ultrafast demagnetization and spin switching, a new frontier for development of faster magnetic storage devices. · Includes numerous worked-out examples and problems in each chapter, with real research codes in density functional theory and quantum chemical calculations provided in the chapters and in the Appendices. This book is intended for undergraduate and graduate students, researchers in physics, chemistry, biology, materials sciences, and engineering.
Download or read book Atomistic Spin Dynamics written by Olle Eriksson and published by Oxford University Press. This book was released on 2017 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several large experimental facilities that focus on detection and probing magnetization dynamics have been realized in Europe, USA and Japan. This book covers theoretical and practical aspects of the vibrant and emerging research field of magnetization dynamics.
Download or read book Ultrafast Magnetization Dynamics written by Simon Woodford and published by Forschungszentrum Jülich. This book was released on 2008 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time resolved Investigation of Ultrafast Magnetization Dynamics written by David Weder and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time Dependent Density Functional Theory written by Carsten Ullrich and published by Oxford University Press. This book was released on 2012 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-dependent density-functional theory (TDDFT) is a quantum mechanical approach for the dynamical properties of electrons in matter. It's widely used in (bio)chemistry and physics to calculate molecular excitation energies and optical properties of materials. This is the first graduate-level text on the formal framework and applications of TDDFT.
Download or read book Handbook of Magnetic Materials written by Ekkes H. Brück and published by Elsevier. This book was released on 2017-11-13 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Magnetic Materials, Volume 26, covers the expansion of magnetism over the last few decades and its applications in research, notably the magnetism of several classes of novel materials that share the presence of magnetic moments with truly ferromagnetic materials. The book is an ideal reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism. Each article contains an extensive description given in graphical, as well as, tabular form, with much emphasis placed on the discussion of the experimental material within the framework of physics, chemistry and material science. - Comprises topical review articles written by leading authorities - Includes a variety of self-contained introductions to a given area in the field of magnetism without requiring recourse to the published literature - Introduces given topics in the field of magnetism - Describes novel trends and achievements in magnetism
Download or read book Ultrafast Magnetization Dynamics Studies Using an X ray Streakcamera written by A. Young and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The spin dynamics of ferromagnetic thin films following an excitation by ultrashort 100-fs near-infrared laser pulses has recently received much attention. Here, a new approach is described using x-ray magnetic circular dichroism to investigated emagnetization and magnetization switching processes. In contrast to magneto-optical measurements, x-ray dichroism has the advantage of determining separately the spin and orbital components of the magnetic moment. The relatively low time resolution of the synchrotron x-ray probe pulses (80 ps FWHM) is overcome by employing an ultrafast x-ray streak camera with a time resolution of
Download or read book Fundamentals of Time Dependent Density Functional Theory written by Miguel A.L. Marques and published by Springer Science & Business Media. This book was released on 2012-01-21 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: There have been many significant advances in time-dependent density functional theory over recent years, both in enlightening the fundamental theoretical basis of the theory, as well as in computational algorithms and applications. This book, as successor to the highly successful volume Time-Dependent Density Functional Theory (Lect. Notes Phys. 706, 2006) brings together for the first time all recent developments in a systematic and coherent way. First, a thorough pedagogical presentation of the fundamental theory is given, clarifying aspects of the original proofs and theorems, as well as presenting fresh developments that extend the theory into new realms—such as alternative proofs of the original Runge-Gross theorem, open quantum systems, and dispersion forces to name but a few. Next, all of the basic concepts are introduced sequentially and building in complexity, eventually reaching the level of open problems of interest. Contemporary applications of the theory are discussed, from real-time coupled-electron-ion dynamics, to excited-state dynamics and molecular transport. Last but not least, the authors introduce and review recent advances in computational implementation, including massively parallel architectures and graphical processing units. Special care has been taken in editing this volume as a multi-author textbook, following a coherent line of thought, and making all the relevant connections between chapters and concepts consistent throughout. As such it will prove to be the text of reference in this field, both for beginners as well as expert researchers and lecturers teaching advanced quantum mechanical methods to model complex physical systems, from molecules to nanostructures, from biocomplexes to surfaces, solids and liquids. From the reviews of LNP 706: “This is a well structured text, with a common set of notations and a single comprehensive and up-to-date list of references, rather than just a compilation of research articles. Because of its clear organization, the book can be used by novices (basic knowledge of ground-state DFT is assumed) and experienced users of TD-DFT, as well as developers in the field.” (Anna I. Krylov, Journal of the American Chemical Society, Vol. 129 (21), 2007) “This book is a treasure of knowledge and I highly recommend it. Although it is a compilation of chapters written by many different leading researchers involved in development and application of TDDFT, the contributors have taken great care to make sure the book is pedagogically sound and the chapters complement each other [...]. It is highly accessible to any graduate student of chemistry or physics with a solid grounding in many-particle quantum mechanics, wishing to understand both the fundamental theory as well as the exponentially growing number of applications. [...] In any case, no matter what your background is, it is a must-read and an excellent reference to have on your shelf.” Amazon.com, October 15, 2008, David Tempel (Cambridge, MA)
Download or read book Handbook of Magnetism and Magnetic Materials written by Michael Coey and published by Springer. This book was released on 2021-11-19 with total page 1679 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook presents a comprehensive survey of magnetism and magnetic materials. The dramatic advances in information technology and electromagnetic engineering make it necessary to systematically review the approved key knowledge and summarize the state of the art in this vast field within one seminal reference work. The book thus delivers up-to-date and well-structured information on a wealth of topics encompassing all fundamental aspects of the underlying physics and materials science, as well as advanced experimental methodology and applications. It features coverage of the host of fascinating and complex phenomena that arise from the use of magnetic fields in e.g. chemistry and biology. Edited by two internationally renowned scholars and featuring authored chapters from leading experts in the field, Springer’s Handbook of Magnetism and Magnetic Materials is an invaluable source of essential reference information for a broad audience of students, researchers, and magnetism professionals.
Download or read book Handbook of Magnetic Materials written by Ekkes H. Brück and published by Elsevier. This book was released on 2020-11-29 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Magnetic Materials, Volume 29, highlights new advances in the field, with this new volume presenting interesting chapters written by an international board of authors on topics such as spin-orbit torque. - Provides the authority and expertise of leading contributors from an international board of authors - Presents the latest release in the Handbook of Magnetic Materials series
Download or read book Magnetism and Synchrotron Radiation written by Eric Beaurepaire and published by Springer Science & Business Media. This book was released on 2010-03-12 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in the synthesis of new materials with often complex, nano-scaled structures require increasingly sophisticated experimental techniques that can probe the electronic states, the atomic magnetic moments and the magnetic microstructures responsible for the properties of these materials. At the same time, progress in synchrotron radiation techniques has ensured that these light sources remain a key tool of investigation, e.g. synchrotron radiation sources of the third generation are able to support magnetic imaging on a sub-micrometer scale. With the Fifth Mittelwihr School on Magnetism and Synchrotron Radiation the tradition of teaching the state-of-the-art on modern research developments continues and is expressed through the present set of extensive lectures provided in this volume. While primarily aimed at postgraduate students and newcomers to the field, this volume will also benefit researchers and lecturers actively working in the field.
Download or read book Electronic Structure of Disordered Alloys Surfaces and Interfaces written by Ilja Turek and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: At present, there is an increasing interest in the prediction of properties of classical and new materials such as substitutional alloys, their surfaces, and metallic or semiconductor multilayers. A detailed understanding based on a thus of the utmost importance for fu microscopic, parameter-free approach is ture developments in solid state physics and materials science. The interrela tion between electronic and structural properties at surfaces plays a key role for a microscopic understanding of phenomena as diverse as catalysis, corrosion, chemisorption and crystal growth. Remarkable progress has been made in the past 10-15 years in the understand ing of behavior of ideal crystals and their surfaces by relating their properties to the underlying electronic structure as determined from the first principles. Similar studies of complex systems like imperfect surfaces, interfaces, and mul tilayered structures seem to be accessible by now. Conventional band-structure methods, however, are of limited use because they require an excessive number of atoms per elementary cell, and are not able to account fully for e.g. substitu tional disorder and the true semiinfinite geometry of surfaces. Such problems can be solved more appropriately by Green function techniques and multiple scattering formalism.
Download or read book Ultrafast Magnetism I written by Jean-Yves Bigot and published by Springer. This book was released on 2014-08-05 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume on Ultrafast Magnetism is a collection of articles presented at the international “Ultrafast Magnetization Conference” held at the Congress Center in Strasbourg, France, from October 28th to November 1st, 2013. This first conference, which is intended to be held every two years, received a wonderful attendance and gathered scientists from 27 countries in the field of Femtomagnetism, encompassing many theoretical and experimental research subjects related to the spins dynamics in bulk or nanostructured materials. The participants appreciated this unique opportunity for discussing new ideas and debating on various physical interpretations of the reported phenomena. The format of a single session with many oral contributions as well as extensive time for poster presentations allowed researchers to have a detailed overview of the field. Importantly, one could sense that, in addition to studying fundamental magnetic phenomena, ultrafast magnetism has entered in a phase where applied physics and engineering are playing an important role. Several devices are being proposed with exciting R&D perspectives in the near future, in particular for magnetic recording, time resolved magnetic imaging and spin polarized transport, therefore establishing connections between various aspects of modern magnetism. Simultaneously, the diversity of techniques and experimental configurations has flourished during the past years, employing in particular Xrays, visible, infra-red and terahertz radiations. It was also obvious that an important effort is being made for tracking the dynamics of spins and magnetic domains at the nanometer scale, opening the pathway to exciting future developments. The concerted efforts between theoretical and experimental approaches for explaining the dynamical behaviors of angular momentum and energy levels, on different classes of magnetic materials, are worth pointing out. Finally it was unanimously recognized that the quality of the scientific oral and poster presentations contributed to bring the conference to a very high international standard.
Download or read book Laser Heating of Metals written by A. M. Prokhorov and published by CRC Press. This book was released on 2018-01-31 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to ensure efficient use of lasers, and for any large-scale implementation, a thorough knowledge of the fundamental laws governing the interaction of radiation with matter is required. Laser Heating of Metals provides a systematic and comprehensive presentation of the fundamental principles underlying the physical and chemical mechanisms governing the interaction of laser radiation with solid targets, and in particular metals in gaseous environments, for a wide range of beam parameters. The authors have been active in the field of interactions between lasers and materials for many years, and this book summarises the results of their work, in particular concerning the action of CO2 lasers on metals. These results are then discussed at some length. Laser Heating of Materials will be of interest to scientists at all levels with an interest in the interaction of radiation with condensed matter, and in particular to those involved in laser cutting and welding etc, and metal-working.
Download or read book Magnetism written by Joachim Stöhr and published by Springer Science & Business Media. This book was released on 2007-01-19 with total page 827 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text book gives a comprehensive account of magnetism, one of the oldest yet most vibrant fields of physics. It spans the historical development, the physical foundations and the continuing research underlying the subject. The book covers both the classical and quantum mechanical aspects of magnetism and novel experimental techniques. Perhaps uniquely, it discusses spin transport and magnetization dynamics phenomena associated with atomically and spin engineered nano-structures against the backdrop of spintronics and magnetic storage and memory applications. The book is for students, and serves as a reference for scientists in academia and research laboratories.
Download or read book Spin Current written by Sadamichi Maekawa and published by Oxford University Press. This book was released on 2017 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a new branch of physics and technology, called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called "spin current", are manipulated and controlled together. This book is intended to provide an introduction and guide to the new physics and applications of spin current.
