Spin Transport and Current Induced Magnetization Dynamics in Magnetic Nanostructures

Spin Transport and Current Induced Magnetization Dynamics in Magnetic Nanostructures PDF Author: Chen, Xi
Publisher:
ISBN:
Category :
Languages : en
Pages : 93

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Spin Transport and Current Induced Magnetization Dynamics in Magnetic Nanostructures

Spin Transport and Current Induced Magnetization Dynamics in Magnetic Nanostructures PDF Author: Chen, Xi
Publisher:
ISBN:
Category :
Languages : en
Pages : 93

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Book Description


Magnetic Nanostructures

Magnetic Nanostructures PDF Author: Hartmut Zabel
Publisher: Springer
ISBN: 3642320422
Category : Science
Languages : en
Pages : 279

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Book Description
Nanomagnetism and spintronics is a rapidly expanding and increasingly important field of research with many applications already on the market and many more to be expected in the near future. This field started in the mid-1980s with the discovery of the GMR effect, recently awarded with the Nobel prize to Albert Fert and Peter Grünberg. The present volume covers the most important and most timely aspects of magnetic heterostructures, including spin torque effects, spin injection, spin transport, spin fluctuations, proximity effects, and electrical control of spin valves. The chapters are written by internationally recognized experts in their respective fields and provide an overview of the latest status.

Spin Dynamics and Damping in Ferromagnetic Thin Films and Nanostructures

Spin Dynamics and Damping in Ferromagnetic Thin Films and Nanostructures PDF Author: Anjan Barman
Publisher: Springer
ISBN: 3319662961
Category : Technology & Engineering
Languages : en
Pages : 166

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Book Description
This book provides a comprehensive overview of the latest developments in the field of spin dynamics and magnetic damping. It discusses the various ways to tune damping, specifically, dynamic and static control in a ferromagnetic layer/heavy metal layer. In addition, it addresses all optical detection techniques for the investigation of modulation of damping, for example, the time-resolved magneto-optical Kerr effect technique.

Spin-transfer Torque in Magnetic Nanostructures

Spin-transfer Torque in Magnetic Nanostructures PDF Author: Jiang Xiao
Publisher:
ISBN:
Category : Nanotechnology
Languages : en
Pages :

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Book Description
This thesis consists of three distinct components: (1) a test of Slocnzewski's theory of spin-transfer torque using the Boltzmann equation, (2) a comparison of macrospin models of spin-transfer dynamics in spin valves with experimental data, and (3) a study of spin-transfer torque in continuously variable magnetization. Slonczewski developed a simple circuit theory for spin-transfer torque in spin valves with thin spacer layer. We developed a numerical method to calculate the spin-transfer torque in a spin valve using Boltzmann equation. In almost all realistic cases, the circuit theory predictions agree well with the Boltzmann equation results. To gain a better understanding of experimental results for spin valve systems, current-induced magnetization dynamics for a spin valve are studied using a single-domain approximation and a generalized Landau-Lifshitz-Gilbert equation. Many features of the experiment were reproduced by the simulations. However, there are two significant discrepancies: the current dependence of the magnetization precession frequency, and the presence and/or absence of a microwave quiet magnetic phase with a distinct magnetoresistance signature. Spin-transfer effects in systems with continuously varying magnetization also have attracted much attention. One key question is under what condition is the spin current adiabatic, i.e., aligned to the local magnetization. Both quantum and semi-classical calculations of the spin current and spin-transfer torque are done in a free-electron Stoner model. The calculation shows that, in the adiabatic limit, the spin current aligns to the local magnetization while the spin density does not. The reason is found in an effective field produced by the gradient of the magnetization in the wall. Non-adiabatic effects arise for short domain walls, but their magnitude decreases exponentially as the wall width increases.

Magnetic Nanostructures in Modern Technology

Magnetic Nanostructures in Modern Technology PDF Author: Bruno Azzerboni
Publisher: Springer
ISBN: 1402063385
Category : Technology & Engineering
Languages : en
Pages : 356

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Book Description
In this book, a team of outstanding scientists in the field of modern magnetic nanotechnologies illustrates the state-of-the-art in several areas of advanced magneto-electronic devices, magnetic micro-electromechanical systems and high density information storage technologies. Providing a unique source of information for the young physicist, chemist or engineer, the book also serves as a crucial reference for the expert scientist and the teacher of advanced university courses.

Nanomagnetism and Spintronics

Nanomagnetism and Spintronics PDF Author: Hiroshi Kohno
Publisher: Elsevier Inc. Chapters
ISBN: 0128086793
Category : Science
Languages : en
Pages : 45

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Book Description
Current-driven domain-wall motion and related phenomena are reviewed from a theoretical point of view. In the first part, the dynamics of a rigid domain wall is described based on the collective-coordinate method. After an elementary introduction, the equations of motion are derived for a wall under current, whose effects enter as a spin-transfer effect and a momentum-transfer effect (force). The wall motion is studied in detail, and several depinning mechanisms are found. In the second part, a microscopic derivation of spin torques is described for slowly varying magnetic texture. In addition to the well-established spin-transfer torque, two new torques are shown to arise from the spin-relaxation process and the nonadiabatic process (reflection) of conduction electrons. These new torques act as forces on a rigid wall. Some related topics are described in the third part, which includes current-driven dynamics of magnetic vortices and the current-induced spin-wave instability and domain-wall nucleation.

Spin Transport and Magnetization Dynamics in Various Magnetic Systems

Spin Transport and Magnetization Dynamics in Various Magnetic Systems PDF Author: Shulei Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages : 143

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Book Description
The general theme of the thesis is the interplay between magnetization dynamics and spin transport. The main presentation is divided into three parts. The first part is devoted to deepening our understanding on magnetic damping of ferromagnetic metals, which is one of the long-standing issues in conventional spintronics that has not been completely understood. For a nonuniformly-magnetized ferromagnetic metal, we find that the damping is nonlocal and is enhanced as compared to that in the uniform case. It is therefore necessary to generalize the conventional Landau-Lifshitz-Gilbert equation to include the additional damping. In a different vein, the decay mechanism of the uniform precession mode has been investigated. We point out the important role of spin-conserving electron-magnon interaction in the relaxation process by quantitatively examining its contribution to the ferromagnetic resonance linewidth. In the second part, a transport theory is developed for magnons which, in addition to conduction electrons, can also carry and propagate spin angular momentum via the magnon current. We demonstrate that the mutual conversion of magnon current and spin current may take place at magnetic interfaces. We also predict a novel magnon-mediated electric drag effect in a metal/magnetic-insulator/metal trilayer structure. This study may pave the way to the new area of insulator-based spintronics. In the third part of thesis, particular attention is paid to the influence the spin orbit coupling on both charge and spin transport. We theoretically investigate magnetotransport anisotropy and the conversion relations of spin and charge currents in various magnetic systems, and apply our results to interpret recent experiments.

Handbook of Nanomagnetism

Handbook of Nanomagnetism PDF Author: Rosa A. Lukaszew
Publisher: CRC Press
ISBN: 9814613053
Category : Science
Languages : en
Pages : 298

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Book Description
This unique handbook compiles and details cutting-edge research in nanomagnetism and its applications in spintronics, magnetoplasmonics, and nonlinear magneto-optics. Fundamental aspects of magnetism relevant to nanodevices and new spin-transfer torque random-access memory (STT-RAM), current-induced domain wall motion memory, and spin torque oscill

Handbook of Spintronics

Handbook of Spintronics PDF Author: Yongbing Xu
Publisher: Springer
ISBN: 9789400768918
Category : Science
Languages : en
Pages : 0

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Book Description
Over two volumes and 1500 pages, the Handbook of Spintronics will cover all aspects of spintronics science and technology, including fundamental physics, materials properties and processing, established and emerging device technology and applications. Comprising 60 chapters from a large international team of leading researchers across academia and industry, the Handbook provides readers with an up-to-date and comprehensive review of this dynamic field of research. The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including an introduction to spin quantum computing. Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrids, magnetic semiconductors and molecular spintronic materials. A separate section reviews the various characterisation methods appropriate to spintronics materials, including STM, spin-polarised photoemission, x-ray diffraction techniques and spin-polarised SEM. The third part of the Handbook contains chapters on the state of the art in device technology and applications, including spin valves, GMR and MTJ devices, MRAM technology, spin transistors and spin logic devices, spin torque devices, spin pumping and spin dynamics and other topics such as spin caloritronics. Each chapter considers the challenges faced by researchers in that area and contains some indications of the direction that future work in the field is likely to take. This reference work will be an essential and long-standing resource for the spintronics community.

Ultrafast Magnetism I

Ultrafast Magnetism I PDF Author: Jean-Yves Bigot
Publisher: Springer
ISBN: 3319077430
Category : Science
Languages : en
Pages : 361

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Book Description
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.