Author: Robin GühnePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Electronic Properties of the Topological Insulators Bi2Se3 and Bi2Te3
Electronic Properties of the Topological Insulators Bi2Se3 and Bi2Te3
Author: Robin GühneOptical and electrical properties of topological insulator Bi2Se3
Author: Jiajun ZhuPublisher: diplom.de
ISBN: 3960676603
Category : Science
Languages : en
Pages : 88
Book Description
Topological insulator is one of the hottest research topics in solid state physics. This is the first book to describe the vibrational spectroscopies and electrical transport of topological insulator Bi2Se3, one of the most exciting areas of research in condensed matter physics. In particular, attempts have been made to summarize and develop the various theories and new experimental techniques developed over years from the studies of Raman scattering, infrared spectroscopy and electrical transport of topological insulator Bi2Se3. It is intended for material and physics researchers and graduate students doing research in the field of optical and electrical properties of topological insulators, providing them the physical understanding and mathematical tools needed to engage research in this quickly growing field. Some key topics in the emerging field of topological insulators are introduced.
Topological insulators Bi2Se3, Bi2Te3, and Sb2Te3: electronic and topological properties of surfaces and thin films from DFT and GW calculations
Author: Tobias FörsterOptical and Electrical Properties of Topological Insulator Bi2Se3
Author: Jiajun ZhuPublisher: Anchor Academic Publishing
ISBN: 3960671601
Category : Science
Languages : en
Pages : 91
Book Description
Topological insulator is one of the hottest research topics in solid state physics. This is the first book to describe the vibrational spectroscopies and electrical transport of topological insulator Bi2Se3, one of the most exciting areas of research in condensed matter physics. In particular, attempts have been made to summarize and develop the various theories and new experimental techniques developed over years from the studies of Raman scattering, infrared spectroscopy and electrical transport of topological insulator Bi2Se3. It is intended for material and physics researchers and graduate students doing research in the field of optical and electrical properties of topological insulators, providing them the physical understanding and mathematical tools needed to engage research in this quickly growing field. Some key topics in the emerging field of topological insulators are introduced.
Optical Properties of Bismuth-Based Topological Insulators
Author: Paola Di PietroPublisher: Springer Science & Business Media
ISBN: 3319019910
Category : Technology & Engineering
Languages : en
Pages : 129
Book Description
Topological Insulators (TIs) are insulators in the bulk, but have exotic metallic states at their surfaces. The topology, associated with the electronic wavefunctions of these systems, changes when passing from the bulk to the surface. This work studies, by means of infrared spectroscopy, the low energy optical conductivity of Bismuth based TIs in order to identify the extrinsic charge contribution of the bulk and to separate it from the intrinsic contribution of the surface state carriers. The extensive results presented in this thesis definitely shows the 2D character of the carriers in Bismuth-based topological insulators. The experimental apparatus and the FTIR technique, the theory of optical properties and Surface Plasmon Polaritons, as well as sample preparation of both crystals and thin films, and the analysis procedures are thoroughly described.
Topological Insulators
Author: InamuddinPublisher: 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.
Advanced Topological Insulators
Author: Huixia LuoPublisher: John Wiley & Sons
ISBN: 111940732X
Category : Technology & Engineering
Languages : en
Pages : 420
Book Description
This book is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for researchers and graduate students preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with the fundamental description on the topological phases of matter such as one, two- and three-dimensional topological insulators, and methods and tools for topological material's investigations, topological insulators for advanced optoelectronic devices, topological superconductors, saturable absorber and in plasmonic devices. Advanced Topological Insulators provides researchers and graduate students with the physical understanding and mathematical tools needed to embark on research in this rapidly evolving field.
STM and STS Studies of Electronic States Near Macroscopic Defects in Topological Insulators
Author: Zhanybek AlpichshevPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Bi2Te3 and Bi2Se3 have been argued to be 3D topological insulators, exhibiting a bulk gap and a single, non-degenerate Dirac fermion surface band topologically protected by time-reversal symmetry. In this dissertation we will discuss the physics of topological insulators. We will show that scanning tunneling spectroscopy studies on high-quality Bi2Te3 and Bi2Se3 crystals exhibit perfect correspondence to ARPES data, hence enabling identification of different regimes measured in the local density of states. Unique to Bi2Te3, we will discuss observation of oscillations of LDOS near a step. Within the main part of the surface band we found that the oscillations are strongly damped, supporting the hypothesis of topological protection. At higher energies, as the surface band becomes concave, oscillations appear which disperse with a particular wave-vector that results from an unconventional hexagonal warping term in the surface-state-band Hamiltonian. For both systems, a "bound state" was observed in the bulk gap region that runs parallel to the edge of the defect and is bound to it at some characteristic distance. An expression that fits the data, and provides insight into the general properties of the surface band near strong structural defects, can be obtained using the full three-dimensional Hamiltonian of the system. In the case of Bi2Se3 whose band structure doesn't exhibit warping we studied the effect of local defects (impurities) on the local density of states. Although no visible interference pattern was detected we observed resonances localized around the defects. Such resonances agree quantitatively with a theory due Biswas and Balatsky which treats impurities as local potential wells interacting with a 2D Dirac gas which models the surface state of a topological insulator.
Topological Insulator and Magnetically Doped Topological Insulator Thin Films by Molecular Beam Epitaxy
Author: Shuang LiPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Searching for energy dissipation-less systems has become increasingly important for low power electronic devices. Topological insulators, a new topological state of quantum matter, have recently been proposed as an emerging material for use in low power electronics, because of the unique transport along its topologically protected edge/surface states. In addition, it has been predicted that the incorporation of magnetic elements into topological insulators could lead to the quantum anomalous Hall state, which is a truly dissipation-less system. However, the material quality of topological insulator thin films remains as a major stumbling block for exploring the novel physics of topological insulators and their proposed applications. In the first part of this thesis, I will first describe an advanced thin film deposition technique, molecular beam epitaxy (MBE) and the mini-MBE system we designed and built for topological insulator thin film growth. Then I will briefly illustrate some basic principles and sample preparation methods for a variety of characterization techniques we used for the material property investigation. In the second part of this thesis, I will present the growth and characterization of topological insulator bismuth telluride thin films grown by a two-step MBE process developed as part of this research. By optimizing the growth recipe and particularly developing the two-step growth method, defect densities were significantly reduced and higher crystal and surface quality bismuth telluride thin films were achieved. The existence of a topological surface state on our bismuth telluride thin films was also confirmed. The Fermi level of our bismuth telluride thin film was tuned to very close to the bulk gap region. The successful growth of centimeter-sized, uniform, high quality topological insulator thin films provides an excellent platform for both fundamental studies of the properties of topological insulators and fabrications of mesoscopic devices. Finally, I will report on the first successful growth of gadolinium substituted bismuth telluride thin films with high Gd concentrations by MBE. We systematically investigated the crystal structure, band structure, magnetic, and electronic properties of gadolinium substituted bismuth telluride thin films. The topological surface state was found to remain intact by Gd substitution into bismuth telluride. Although ferromagnetic behavior in gadolinium substituted bismuth telluride thin films was not observed above 2K by both magnetic and magneto-transport measurements, gadolinium substituted bismuth telluride thin films were found to have a Curie susceptibility due to the paramagnetic Gd ions with an atomic magnetic moment of 6.93 Bohr magneton per Gd ion, which suggests that it is possible to realize dissipation-less transport with a small external magnetic field or with a ferromagnetic layer on top of gadolinium substituted bismuth telluride thin films.