Concepts In Spin Electronics

Recently, a new branch of physics and nanotechnology called spin electronics has emerged, which aims at simultaneously exploiting the charge and spin of electrons in the same device. The aim of this book is to present new directions in the development of spin electronics in both the basic physics and the technology which will become the foundation of future electronics.

Nowadays information technology is based on semiconductor and ferromagnetic materials. Information processing and computation are based on electron charge in semiconductor transistors and integrated circuits, and information is stored on magnetic high-density hard disks based on the physics of the electron spins. Recently, a new branch of physics and nanotechnology, called magneto-electronics, spintronics, or spin electronics, has emerged, which aims at simultaneously exploiting both the charge and the spin of electrons in the same device. A broader goal is to develop new functionality that does not exist separately in a ferromagnet or a semiconductor. The aim of this book is to present new directions in the development of spin electronics in both the basic physics and the technology which will become the foundation of future electronics.

This book highlights the overview of Spintronics, including What is Spintronics ?; Why Do We Need Spintronics ?; Comparative merit-demerit of Spintronics and Electronics ; Research Efforts put on Spintronics ; Quantum Mechanics of Spin; Dynamics of magnetic moments : Landau-Lifshitz-Gilbert Equation; Spin-Dependent Band Gap in Ferromagnetic Materials; Functionality of ‘Spin’ in Spintronics; Different Branches of Spintronics etc. Some important notions on basic elements of Spintronics are discussed here, such as – Spin Polarization, Spin Filter Effect, Spin Generation and Injection, Spin Accumulation, Different kinds of Spin Relaxation Phenomena, Spin Valve, Spin Extraction, Spin Hall Effect, Spin Seebeck Effect, Spin Current Measurement Mechanism, Magnetoresistance and its different kinds etc. Concept of Giant Magnetoresistance (GMR), different types of GMR, qualitative and quantitative explanation of GMR employing Resistor Network Theory are presented here. Tunnelling Magnetoresistance (TMR), Magnetic Junctions, Effect of various parameters on TMR, Measurement of spin relaxation length and time in the spacer layer are covered here. This book highlights the concept of Spin Transfer Torque (STT), STT in Ferromagnetic Layer Structures, STT driven Magnetization Dynamics, STT in Magnetic Multilayer Nanopillar etc. This book also sheds light on Magnetic Domain Wall (MDW) Motion, Ratchet Effect in MDW motion, MDW motion velocity measurements, Current-driven MDW motion, etc. The book deals with the emerging field of spintronics, i.e., Opto-spintronics. Special emphasis is given on ultrafast optical controlling of magnetic states of antiferromagnet, Spin-photon interaction, Faraday Effect, Inverse Faraday Effect and outline of different all-optical spintronic switching. One more promising branch i.e., Terahertz Spintronics is also covered. Principle of operation of spintronic terahertz emitter, choice of materials, terahertz writing of an antiferromagnetic magnetic memory device is discussed. Brief introduction of Semiconductor spintronics is presented that includes dilute magnetic semiconductor, feromagnetic semiconductor, spin polarized semiconductor devices, three terminal spintronic devices, Spin transistor, Spin-LED, and Spin-Laser. This book also emphasizes on several modern spintronics devices that includes GMR Read Head of Modern Hard Disk Drive, MRAM, Position Sensor, Biosensor, Magnetic Field sensor, Three Terminal Magnetic Memory Devices, Spin FET, Race Track Memory and Quantum Computing.

Using spin to replace or augment the role of charge in signal processing devices, computing systems and circuits may improve speed, power consumption, and device density in some cases—making the study of spinone of the fastest-growing areas in micro- and nanoelectronics. With most of the literature on the subject still highly advanced and heavily theoretical, the demand for a practical introduction to the concepts relating to spin has only now been filled. Explains effects such as giant magnetoresistance, the subject of the 2007 Nobel Prize in physics Introduction to Spintronics is an accessible, organized, and progressive presentation of the quantum mechanical concept of spin. The authors build a foundation of principles and equations underlying the physics, transport, and dynamics of spin in solid state systems. They explain the use of spin for encoding qubits in quantum logic processors; clarify how spin-orbit interaction forms the basis for certain spin-based devices such as spintronic field effect transistors; and discuss the effects of magnetic fields on spin-based device performance. Covers active hybrid spintronic devices, monolithic spintronic devices, passive spintronic devices, and devices based on the giant magnetoresistance effect The final chapters introduce the burgeoning field of spin-based reversible logic gates, spintronic embodiments of quantum computers, and other topics in quantum mechanics that have applications in spintronics. An Introduction to Spintronics provides the knowledge and understanding of the field needed to conduct independent research in spintronics.

For 50 years conventional electronics has ignored the electron spin. The manipulation and utilisation of the electron spin heralds an exciting and rapidly changing era in electronics, combining the disciplines of magnetism and traditional electronics. The first generation of "spintronic" devices (such as read heads based on giant magnetoresistance or non-volatile magnetic random access memories) have already gained dominant positions in the market place. This volume, the first of its kind on spin electronics describes all the essential topics for new researchers entering the field. It covers magnetism and semiconductor basics, micromagnetism, experimental techniques, materials science, device fabrication and new developments in spin-dependent processes. At the end of most chapters are a number of exercises and worked problems to aid the reader in understanding this fascinating new field.

Semiconductor Spintronics, as an emerging research discipline and an important advanced field in physics, has developed quickly and obtained fruitful results in recent decades. This volume is the first monograph summarizing the physical foundation and the experimental results obtained in this field. With the culmination of the authors'' extensive working experiences, this book presents the developing history of semiconductor spintronics, its basic concepts and theories, experimental results, and the prospected future development. This unique book intends to provide a systematic and modern foundation for semiconductor spintronics aimed at researchers, professors, post-doctorates, and graduate students, and to help them master the overall knowledge of spintronics.a

Introduction to Spintronics provides an accessible, organized, and progressive presentation of the quantum mechanical concept of spin and the technology of using it to store, process, and communicate information. Fully updated and expanded to 18 chapters, this Second Edition: Reflects the explosion of study in spin-related physics, addressing seven important physical phenomena with spintronic device applications Discusses the recently discovered field of spintronics without magnetism, which allows one to manipulate spin currents by purely electrical means Explores lateral spin-orbit interaction and its many nuances, as well as the possibility to implement spin polarizers and analyzers using quantum point contacts Introduces the concept of single-domain-nanomagnet-based computing, an ultra-energy-efficient approach to compute and store information using nanomagnets, offering a practical rendition of single-spin logic architecture ideas and an alternative to transistor-based computing hardware Features many new drill problems, and includes a solution manual and figure slides with qualifying course adoption Still the only known spintronics textbook written in English, Introduction to Spintronics, Second Edition is a must read for those interested in the science and technology of storing, processing, and communicating information via the spin degree of freedom of electrons.

Spintronics refers to the study of the intrinsic spin of the electron and its associated magnetic moment. It has potential applications in the area of data storage and transfer. Spintronic systems are prominently present in dilute magnetic semiconductors (DMS) and Heusler alloys. Some metal-based spintronic devices are tunnel magnetoresistance, spin-transfer torque and spin-wave logic devices. Non-volatile spin-logic devices that enable scaling are being widely studied. Spin-transfer and torque-based logic devices that use spins and magnets for information processes are also being developed. This book provides comprehensive insights into the field of spintronics. Such selected concepts that redefine this field have been presented herein. Coherent flow of topics, student-friendly language and extensive use of examples make this textbook an invaluable source of knowledge.