Confined Magnon Modes And Anisotropic Exchange Interaction In Ultrathin Co Films

A fundamental need in wireless communication and modern computer processors is to fabricate faster, smaller, and lower power-consumption circuits. A promising approach is the utilization of spin waves, or rather, magnons in ferromagnetic films. Quantum confinement in ultra-thin films permits the coexistence of several exchange-dominated magnon modes with terahertz-range frequencies and sub-nanometer length scales. By means of spin-polarized electron energy loss spectroscopy (SPEELS), these exchange-dominated terahertz magnons are directly probed in ultra-thin cobalt films on Ir(001), Cu(001) and Pt(111) single crystal surfaces. The dispersion relation of the quantized magnon modes depends particularly on the interatomic exchange interaction in individual layers. By tuning the exchange interaction, modes with opposite group velocities, and thus an opposite propagation direction of the wave packets, can be generated. Ab initio theoretical calculations as well as an analytical Heisenberg model reveal a spatial localization of the modes at the surface, interior, and interface of the film that opens an experimental access to the layer-dependent magnetic properties. In itinerant ferromagnets like cobalt the magnetic properties depend sensitively on many-body correlation effects in the electronic structure. Here, it is shown for the first time that spin-dependent correlations lead to a pronounced renormalization of the energy of the highest magnon mode by up to 260 meV, explaining the significant overestimation of theoretically predicted magnon energies and interatomic exchange interaction found in literature.

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.

Solid State Physics, Volume 72, the latest release in this long-running serial, highlights new advances in the field with this new volume presenting interesting and timely chapters authored by an international board of experts. Chapters in this release include Roadmap: The influence of the internal domain wall structure on spin wave band structure in periodic magnetic stripe domain patterns, The influence of the internal domain wall structure on spin wave band structure in periodic magnetic stripe domain patterns, and more. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in the Solid State Physics series

Recent Advances in Topological Ferroics and Their Dynamics, Volume 70 in the Solid State Physics series, provides the latest information on the branch of physics that is primarily devoted to the study of matter in its solid phase, especially at the atomic level. This prestigious serial presents timely and state-of-the-art reviews pertaining to all aspects of solid state physics. Contains contributions from leading authorities in the study of solid state physics, especially at the atomic level Informs and updates on all the latest developments in the field Presents timely, state-of-the-art reviews pertaining to all aspects of solid state physics

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.

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.

This volume of Solid State Physics provides a broad review on recent advances in the field of magnetic insulators, ranging from new spin effects to thin film growth and high-frequency applications. It covers both theoretical and experimental progress. The topics include the use of magnetic insulators to produce and transfer spin currents, the excitation of spin waves in magnetic insulators by spin transfer torque, interplay between the spin and heat transports in magnetic insulator/normal metal heterostructures, nonlinear spin waves in thin films, development of high-quality nanometer thick films, and applications of magnetic insulators in rf, microwave, and terahertz devices, among others. The volume not only presents introductions and tutorials for those just entering the field, but also provides comprehensive yet timely summaries to specialists in the field. Solid-state physics is the branch of physics primarily devoted to the study of matter in its solid phase, especially at the atomic level. This prestigious series presents timely and state-of-the-art reviews pertaining to all aspects of solid-state physics. Contributions from leading authorities Informs and updates on all the latest developments in the field

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.

Magnetic nanowires and microwires are key tools in the development ofenhanced devices for information technology (memory and data processing) andsensing. Offering the combined characteristics of high density, high speed, andnon-volatility, they facilitate reliable control of the motion of magnetic domainwalls; a key requirement for the development of novel classes of logic and storagedevices. Part One introduces the design and synthesis of magnetic nanowires andmicrowires, reviewing the growth and processing of nanowires and nanowireheterostructures using such methods as sol-gel and electrodepositioncombinations, focused-electron/ion-beam-induced deposition, chemicalvapour transport, quenching and drawing and magnetic interactions. Magneticand transport properties, alongside domain walls, in nano- and microwiresare then explored in Part Two, before Part Three goes on to explore a widerange of applications for magnetic nano- and microwire devices, includingmemory, microwave and electrochemical applications, in addition to thermalspin polarization and configuration, magnetocalorific effects and Bloch pointdynamics. Detailed coverage of multiple key techniques for the growth and processing of nanowires and microwires Reviews the principles and difficulties involved in applying magnetic nano- and microwires to a wide range of applications Combines the expertise of specialists from around the globe to give a broad overview of current and future trends