Room Temperature Spin-orbit Torque Switching Induced by a Topological Insulator PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Room Temperature Spin-orbit Torque Switching Induced by a Topological Insulator PDF full book. Access full book title Room Temperature Spin-orbit Torque Switching Induced by a Topological Insulator by Jiahao Han. Download full books in PDF and EPUB format.
Author: Jiahao Han Publisher: ISBN: Category : Languages : en Pages : 63
Book Description
Recent studies on the topological insulators have attracted great attention due to the rich spin-orbit physics and promising applications in spintronic devices. The strongly spin-moment coupled electronic states have been extensively pursued to realize efficient spin-orbit torque switching. However, so far current-induced magnetic switching with topological insulators has been observed only at cryogenic temperatures. Whether the topologically protected electronic states in topological insulators can benefit to spintronic applications at room temperature remains a controversial issue. In this thesis, spin-orbit-torque-induced magnetic switching is realized in topological insulator/ferrimagnet heterostructure at room temperature. Ferrimagnetic CoTb alloy with robust bulk perpendicular magnetic anisotropy is directly grown on a classical topological insulator Bi2 Se3. The low switching current density provides definitive proof of the high spin-orbit torque efficiency from topological insulators. The comparison between Bi2Se3 and (Bi,Sb)2Te3 with less bulk conductivity suggests the surface states plays a significant role in generated the efficient spin-orbit torques. Furthermore, the effective spin Hall angle of topological insulators is determined to be several times larger than commonly used heavy metals. These results demonstrate the robustness of topological insulators as a spin-orbit torque switching material and provide an avenue towards applicable topological insulator-based spintronic devices.
Author: Jiahao Han Publisher: ISBN: Category : Languages : en Pages : 63
Book Description
Recent studies on the topological insulators have attracted great attention due to the rich spin-orbit physics and promising applications in spintronic devices. The strongly spin-moment coupled electronic states have been extensively pursued to realize efficient spin-orbit torque switching. However, so far current-induced magnetic switching with topological insulators has been observed only at cryogenic temperatures. Whether the topologically protected electronic states in topological insulators can benefit to spintronic applications at room temperature remains a controversial issue. In this thesis, spin-orbit-torque-induced magnetic switching is realized in topological insulator/ferrimagnet heterostructure at room temperature. Ferrimagnetic CoTb alloy with robust bulk perpendicular magnetic anisotropy is directly grown on a classical topological insulator Bi2 Se3. The low switching current density provides definitive proof of the high spin-orbit torque efficiency from topological insulators. The comparison between Bi2Se3 and (Bi,Sb)2Te3 with less bulk conductivity suggests the surface states plays a significant role in generated the efficient spin-orbit torques. Furthermore, the effective spin Hall angle of topological insulators is determined to be several times larger than commonly used heavy metals. These results demonstrate the robustness of topological insulators as a spin-orbit torque switching material and provide an avenue towards applicable topological insulator-based spintronic devices.
Author: Publisher: ISBN: Category : Languages : en Pages : 6
Book Description
Topological insulators are new states of quantum matter with surface states protected by the time-reversal symmetry. In this work, we perform first-principle electronic structure calculations for Sb2Te3, Sb2Se3, Bi2Te3 and Bi2Se3 crystals. Our calculations predict that Sb2Te3, Bi2T e3 and Bi2Se3 are topological insulators, while Sb2Se3 is not. In particular, Bi2Se3 has a topologically non-trivial energy gap of 0.3eV, suitable for room temperature applications. We present a simple and unified continuum model which captures the salient topological features of this class of materials. These topological insulators have robust surface states consisting of a single Dirac cone at the [Lambda] point.
Author: Publisher: Elsevier ISBN: 0444633189 Category : Science Languages : en Pages : 349
Book Description
Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was thought that all band insulators are essentially equivalent, the new theory predicts two distinct classes of band insulators in two spatial dimensions and 16 classes in three dimensions. These "topological" insulators exhibit a host of unusual physical properties, including topologically protected gapless surface states and exotic electromagnetic response, previously thought impossible in such systems. Within a short time, this new state of quantum matter, topological insulators, has been discovered experimentally both in 2D thin film structures and in 3D crystals and alloys. It appears that topological insulators are quite common in nature, and there are dozens of confirmed substances that exhibit this behavior. Theoretical and experimental studies of these materials are ongoing with the goal of attaining the fundamental understanding and exploiting them in future practical applications. - Usable as a textbook for graduate students and as a reference resource for professionals - Includes the most recent discoveries and visions for future technological applications - All authors are prominent in the field
Author: Frank Ortmann Publisher: John Wiley & Sons ISBN: 3527681604 Category : Technology & Engineering Languages : en Pages : 434
Book Description
There are only few discoveries and new technologies in physical sciences that have the potential to dramatically alter and revolutionize our electronic world. Topological insulators are one of them. The present book for the first time provides a full overview and in-depth knowledge about this hot topic in materials science and condensed matter physics. Techniques such as angle-resolved photoemission spectrometry (ARPES), advanced solid-state Nuclear Magnetic Resonance (NMR) or scanning-tunnel microscopy (STM) together with key principles of topological insulators such as spin-locked electronic states, the Dirac point, quantum Hall effects and Majorana fermions are illuminated in individual chapters and are described in a clear and logical form. Written by an international team of experts, many of them directly involved in the very first discovery of topological insulators, the book provides the readers with the knowledge they need to understand the electronic behavior of these unique materials. Being more than a reference work, this book is essential for newcomers and advanced researchers working in the field of topological insulators.
Author: M. Zahid Hasan Publisher: Elsevier Inc. Chapters ISBN: 0128086874 Category : Science Languages : en Pages : 50
Book Description
Topological Surface States (TSS) represent new types of two dimensional electron systems with novel and unprecedented properties distinct from any quantum Hall-like or spin-Hall effects. Their topological order can be realized at room temperatures without magnetic fields and they can be turned into magnets, exotic superconductors or Kondo insulators leading to worldwide interest and activity in the topic. We review the basic concepts defining such topological matter and the key experimental probe that revealed the topological order in the bulk of these spin-orbit interaction dominated insulators. This review focuses on the key results that demonstrated the fundamental topological properties such as spin-momentum locking, non-trivial Berrys phases, mirror Chern number, absence of backscattering, protection by time-reversal and other discrete (mirror) symmetries and their remarkable persistence up to the room temperature elaborating on results first discussed by M.Z. Hasan and C.L. Kane in the Rev. of Mod. Phys., 82, 3045 (2010). Additionally, key results on broken symmetry phases such as quantum magnetism and uperconductivity induced in topological materials are briefly discussed.
Author: Yongbing Xu Publisher: Springer ISBN: 9789400768918 Category : Science Languages : en Pages : 0
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.
Author: Inamuddin Publisher: Materials Research Forum LLC ISBN: 1644902850 Category : Technology & Engineering Languages : en Pages : 195
Book Description
A topological insulator is an area that has yet to be fully explored and developed. The charge-induced bandgap fluctuation in the best-known bismuth-chalcogenide-based topological insulators is approximately 10MeV in magnitude. The major focus has shifted to the investigation of the presence of high-symmetry electronic bands as well as the utilization of easily produced materials. As the subject of topological insulators is still in the nascent stage, there is growing research and knowledge in the emerging field. This book is intended to provide the readers with an understanding of the needs and application of these materials. Keywords: Topological Insulators, Insulators, One-Dimensional Topological Insulators, Graphene, Magnetic Topological Insulator, Antiferromagnetic Phase, Ferromagnetic Phase, Topological Superconductor, Nonlinear Optical Behavior, Saturable Absorber, Quantum, Band Gap, Photonic Topological Insulators.
Author: Gregory Tkachov Publisher: CRC Press ISBN: 9814613266 Category : Science Languages : en Pages : 180
Book Description
This book is the result of dynamic developments that have occurred in condensed matter physics after the recent discovery of a new class of electronic materials: topological insulators. A topological insulator is a material that behaves as a band insulator in its interior, while acting as a metallic conductor at its surface. The surface current car
Author: Inamuddin Publisher: Materials Research Forum LLC ISBN: 1644902842 Category : Technology & Engineering Languages : en Pages : 195
Book Description
A topological insulator is an area that has yet to be fully explored and developed. The charge-induced bandgap fluctuation in the best-known bismuth-chalcogenide-based topological insulators is approximately 10MeV in magnitude. The major focus has shifted to the investigation of the presence of high-symmetry electronic bands as well as the utilization of easily produced materials. As the subject of topological insulators is still in the nascent stage, there is growing research and knowledge in the emerging field. This book is intended to provide the readers with an understanding of the needs and application of these materials. Keywords: Topological Insulators, Insulators, One-Dimensional Topological Insulators, Graphene, Magnetic Topological Insulator, Antiferromagnetic Phase, Ferromagnetic Phase, Topological Superconductor, Nonlinear Optical Behavior, Saturable Absorber, Quantum, Band Gap, Photonic Topological Insulators.
Author: Joseph Maciejko Publisher: Stanford University ISBN: Category : Languages : en Pages : 242
Book Description
This dissertation brings together a number of topics in the theory of time-reversal invariant topological insulators. The first four chapters are devoted to the transport properties of the two-dimensional (2D) quantum spin Hall state. We explain nonlocal transport measurements in mercury telluride (HgTe) quantum wells in terms of a Landauer-Büttiker theory of helical edge transport and confirm the discovery of the quantum spin Hall state in this material. We find that decoherence can lead to backscattering without breaking microscopic time-reversal symmetry. As an example of incoherent scattering, we study a Kondo impurity in an interacting helical edge liquid. A renormalization group analysis shows the existence of an impurity quantum phase transition governed by the Luttinger parameter of the edge liquid between a local helical Fermi liquid with T^6 scaling of the low-temperature conductance, and an insulating strongly correlated phase with fractionally charged emergent excitations. In the presence of a time-reversal symmetry breaking magnetic field, it is known that even coherent scattering can lead to backscattering. Through exact numerical diagonalization we find that nonmagnetic quenched disorder has a strong localizing effect on the edge transport if the disorder strength is comparable to the bulk gap. The predicted magnetoconductance agrees qualitatively with experiment. The last two chapters are devoted to 3D topological insulators. We propose a combined magnetooptical Kerr and Faraday rotation experiment as a universal measure of the Z_2 invariant. Finally, we propose a fractional generalization of 3D topological insulators in strongly correlated systems, characterized by ground state degeneracy on topologically nontrivial spatial 3-manifolds, a quantized fractional bulk magnetoelectric polarizability without time-reversal symmetry breaking, and a halved fractional quantum Hall effect on the surface.
Author: Jiahao Han
Author: Jiahao Han
Author: 
Author: 
Author: Frank Ortmann
Author: M. Zahid Hasan
Author: Yongbing Xu
Author: Inamuddin
Author: Gregory Tkachov
Author: Inamuddin
Author: Joseph Maciejko