The Novel Topological Insulator Materials of Crystal and Electronic Structure Studied by Angle-resolved Photoemission Spectroscopy PDF Download

Author: 莊霈于
Publisher:
ISBN:
Category :
Languages : en
Pages : 96

View

Book Description

Author: Frank Ortmann
Publisher: John Wiley & Sons
ISBN: 3527681604
Category : Technology & Engineering
Languages : en
Pages : 434

View

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: Zhongkai Liu
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Electronic Structure is the key factor for identifying new material or phases and understanding the underlying physics behind emergent phenomena. In the investigation of the electronic structures of novel complex materials, the angular resolved photoemission spectroscopy (ARPES) serves as a powerful tool. The thesis summarizes two of my graduate research projects, which both involves probing electronic structures and analyzing underlying physics on novel complex materials with state-of-the-art ARPES techniques: In the first part, I would summarize our investigation on the materials with non-trivial topology. I would start from our initial work on the three-dimensional topological insulators where we identified the characteristic surface states and verified that they are robust from perturbations. Following the line of search, we discovered three-dimensional topological insulators with other interesting properties, including the strongly inversion asymmetric topological insulator BiTeCl, and the strongly correlated topological Kondo insulator SmB6. We further extended our research to Na3Bi and Cd3As2, where we found them hosting a three-dimensional Dirac point and are first examples of topological Dirac semimetals, a three-dimensional analogue of graphene. In the second part of my thesis, I would discuss the ARPES study on the electron correlation level in the iron chalcogenide family Fe(Se, Te). For the parent compound FeTe, we discovered "peak-dip-hump" spectra with heavily renormalized quasiparticles in the low temperature antiferromagnetic state, characteristic of coherent polarons seen in other correlated materials. The increase of Se ratio leads to an incoherent to coherent crossover in the electronic structure. Furthermore, the reduction of the electronic correlation in Fe(Se, Te) evolves in an orbital-dependent way, where the dxy orbital is influenced most significantly. Finally, in comparison with other members of iron chalcogenides (AxFe2-ySe2, A=K, Rb, Cs; and monolayer FeSe film on SrTiO3 substrate), we found the strong correlation behavior is universal in all iron chalcogenides. Specifically, the dxy orbital is always heavily renormalized and loses spectral weight upon raising temperature. Several physical models of the orbital dependent physics and electron correlations would be discussed.

Author: Christian Pauly
Publisher: Springer
ISBN: 3658118113
Category : Science
Languages : en
Pages : 172

View

Book Description
Christian Pauly demonstrates the strong topological properties of the technologically relevant phase change materials Sb2Te3 and Ge2Sb2Te5 by using two powerful techniques for mapping the surface electronic structure: scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES). In the case of a phase change material, this opens up the possibility of switching between an insulating amorphous and a conducting topological phase on nanosecond-time scales. Moreover, the author presents first experimental results of a weak topological insulator, namely on the bismuth-based graphene-like sheet system Bi14Rh3I9, revealing a topologically protected one-dimensional edge channel as its fingerprint. The edge state is as narrow as 0.8 nm, making it extremely attractive to device physics. Those strong and weak topological insulators are a new phase of quantum matter giving rise to robust boundary states which are protected from backscattering and localization.

Author: Alexej Herdt
Publisher: Forschungszentrum Jülich
ISBN: 3893368310
Category :
Languages : en
Pages : 145

View

Book Description

Author: Ryo Noguchi
Publisher: Springer Nature
ISBN: 9811918740
Category : Science
Languages : en
Pages : 139

View

Book Description
This book presents the observation and the control of spin-polarized electrons in Rashba thin films and topological insulators, including the first observations of a weak topological insulator (WTI) and a higher-order topological insulator (HOTI) in bismuth halides. It begins with a general review of electronic structures at the solid surface and mentions that an electron spin at a surface is polarized due to the Rashba effect or topological insulator states with strong spin-orbit coupling. Subsequently it describes the experimental techniques used to study these effects, that is, angle-resolved photoemission spectroscopy (ARPES). Further it moves its focus onto the experimental investigations, in which mainly two different systems—noble metal thin films with the Rashba effects and bismuth halides topological insulators—are used. The study of the first system discusses the role of wavefunctions in spin-splitting and demonstrates a scaling law for the Rashba effect in quantum well films for the first time. High-resolution spin-resolved ARPES plays a vital role in systematically trace the thickness-evolution of the effect. The study of the latter material is the first experimental demonstration of both a WTI and HOTI state in bismuth iodide and bismuth bromide, respectively. Importantly, nano-ARPES with high spatial resolution is used to confirm the topological surface states on the side surface of the crystal, which is the hallmark of WTIs. The description of the basic and recently-developed ARPES technique with spin-resolution or spatial-resolution, essential in investigating spin-polarized electrons at a crystal surface, makes the book a valuable source for researchers not only in surface physics or topological materials but also in spintronics and other condensed-matter physics.

Author:
Publisher: Elsevier
ISBN: 0444633189
Category : Science
Languages : en
Pages : 349

View

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: Jonathan A. Sobota
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Most macroscopic properties of a material (electrical, thermal, and optical) can be understood on the basis of its band structure and the dynamical behavior of its electrons. However, resolving electron dynamics directly is difficult using conventional techniques because the underlying interactions typically occur on a femtosecond timescale. Ultrafast photoemission spectroscopy is an experimental technique which can probe electronic band structure with femtosecond time resolution. This dissertation presents work using this technique to study dynamic phenomena in the topological insulator Bi2Se3, a fascinating material due to the coexistence of its insulating bulk and metallic surface electronic structures. It will demonstrate three types of novel measurements that can be performed with ultrafast photoemission spectroscopy which are unattainable by other methods: (1) By performing two-photon photoemission (2PPE) spectroscopy, it is possible to resolve unoccupied band structure above the Fermi level. In Bi2Se3 this reveals a second, topologically protected surface state. (2) Time-resolved 2PPE (tr2PPE) is used to record real-time "movies" of the electron relaxation which follows optical excitation. This allows for the identification of intra- and inter- band electron scattering pathways in the material. Temperature-dependent tr2PPE measurements are performed on the conduction band to help understand the role of electron-phonon coupling. A model of fundamental electron-phonon scattering processes is implemented to describe the results. (3) In a time- and angle- resolved photoemission spectroscopy (trARPES) experiment, intense optical excitation is used to drive coherent motion of A1g optical phonon modes in Bi2Se3. These modes lead to periodic binding energy shifts in the bulk conduction band and surface state. A slight red-shift of the phonon frequency is observed in the surface state, which is used to deduce a softening of the phonon due to the abrupt termination of the crystal at its surface.

Author:
Publisher: Academic Press
ISBN: 0323915108
Category : Science
Languages : en
Pages : 240

View

Book Description
Topological Insulator and Related Topics, Volume 108 in the Semiconductors and Semimental series, highlights new advances in the field, with this new volume presenting interesting chapters on topics such as Majorana modes at the ends of one dimensional topological superconductors, Optical/electronic properties of Weyl semimetals, High magnetic fields to unveil the electronic structure, magnetic field-induced transitions, and unconventional transport properties of topological semimetals, New aspects of strongly correlated superconductivity in the nearly flat-band regime, Anomalous transport properties in topological semimetals, Pseudo-gauge field and piezo-electromagnetic response in topological materials, Topological Gapped States Protected by Spatial Symmetries, and more. - Provides the authority and expertise of leading contributors from an international board of authors - Presents the latest release in the Semiconductors and Semimetals series - Updated release includes the latest information on Topological Insulator and Related Topics

Author: Huixia Luo
Publisher: John Wiley & Sons
ISBN: 1119407338
Category : Technology & Engineering
Languages : en
Pages : 416

View

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.