Relevant bibliographies by topics / Topological insulator layer

Academic literature on the topic 'Topological insulator layer'

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Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Topological insulator layer"

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Darabi, Amir, Manuel Collet, and Michael J. Leamy. "Experimental realization of a reconfigurable electroacoustic topological insulator." Proceedings of the National Academy of Sciences 117, no. 28 (June 29, 2020): 16138–42. http://dx.doi.org/10.1073/pnas.1920549117.

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A substantial challenge in guiding elastic waves is the presence of reflection and scattering at sharp edges, defects, and disorder. Recently, mechanical topological insulators have sought to overcome this challenge by supporting back-scattering resistant wave transmission. In this paper, we propose and experimentally demonstrate a reconfigurable electroacoustic topological insulator exhibiting an analog to the quantum valley Hall effect (QVHE). Using programmable switches, this phononic structure allows for rapid reconfiguration of domain walls and thus the ability to control back-scattering resistant wave propagation along dynamic interfaces for phonons lying in static and finite-frequency regimes. Accordingly, a graphene-like polyactic acid (PLA) layer serves as the host medium, equipped with periodically arranged and bonded piezoelectric (PZT) patches, resulting in two Dirac cones at theKpoints. The PZT patches are then connected to negative capacitance external circuits to break inversion symmetry and create nontrivial topologically protected bandgaps. As such, topologically protected interface waves are demonstrated numerically and validated experimentally for different predefined trajectories over a broad frequency range.
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Deng, Yujun, Yijun Yu, Meng Zhu Shi, Zhongxun Guo, Zihan Xu, Jing Wang, Xian Hui Chen, and Yuanbo Zhang. "Quantum anomalous Hall effect in intrinsic magnetic topological insulator MnBi2Te4." Science 367, no. 6480 (January 23, 2020): 895–900. http://dx.doi.org/10.1126/science.aax8156.

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In a magnetic topological insulator, nontrivial band topology combines with magnetic order to produce exotic states of matter, such as quantum anomalous Hall (QAH) insulators and axion insulators. In this work, we probe quantum transport in MnBi2Te4 thin flakes—a topological insulator with intrinsic magnetic order. In this layered van der Waals crystal, the ferromagnetic layers couple antiparallel to each other; atomically thin MnBi2Te4, however, becomes ferromagnetic when the sample has an odd number of septuple layers. We observe a zero-field QAH effect in a five–septuple-layer specimen at 1.4 kelvin, and an external magnetic field further raises the quantization temperature to 6.5 kelvin by aligning all layers ferromagnetically. The results establish MnBi2Te4 as an ideal arena for further exploring various topological phenomena with a spontaneously broken time-reversal symmetry.
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Lei, Chao, Shu Chen, and Allan H. MacDonald. "Magnetized topological insulator multilayers." Proceedings of the National Academy of Sciences 117, no. 44 (October 19, 2020): 27224–30. http://dx.doi.org/10.1073/pnas.2014004117.

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We discuss the magnetic and topological properties of bulk crystals and quasi–two-dimensional (quasi-2D) thin films formed by stacking intrinsic magnetized topological insulator (for example, Mn (SbxBi1−x)2X4with X = Se,Te) septuple layers and topological insulator quintuple layers in arbitrary order. Our analysis makes use of a simplified model that retains only Dirac cone degrees of freedom on both surfaces of each septuple or quintuple layer. We demonstrate the model’s applicability and estimate its parameters by comparing with ab initio density-functional theory (DFT) calculations. We then employ the coupled Dirac cone model to provide an explanation for the dependence of thin-film properties, particularly the presence or absence of the quantum anomalous Hall effect, on film thickness, magnetic configuration, and stacking arrangement, and to comment on the design of Weyl superlattices.
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Chang, Kai-Wei, Wei Ji, and Chao-Cheng Kaun. "Layer-separable and gap-tunable topological insulators." Physical Chemistry Chemical Physics 19, no. 5 (2017): 3932–36. http://dx.doi.org/10.1039/c6cp06932k.

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Jiang, Guobao, Yuan Zhou, Lulu Wang, and Ying Chen. "PMMA Sandwiched Bi2Te3 Layer as a Saturable Absorber in Mode-Locked Fiber Laser." Advances in Condensed Matter Physics 2018 (December 18, 2018): 1–5. http://dx.doi.org/10.1155/2018/7578050.

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In this paper, we fabricated a PMMA sandwiched Bi2Te3 self-assembly layer as a saturable absorber device, which was used as a passive mode locker for ultrafast pulse generation at the telecommunication band. Nanosheets of Bi2Te3 as a bulk topological insulator were successfully synthesized through a solvothermal treatment and self-assemble method to form a thin film at a water-air interface. In order to transfer the Bi2Te3 self-assembly layer to the optical fiber end, we design a construction of two PMMA layers sandwiched self-assembly layer. By incorporating this saturable absorber into an erbium-doped fiber laser, femtosecond mode-locking operation was experimentally demonstrated. The output pulse width is about 505 fs. Our results indicate that PMMA sandwiched topological insulator layer structure could be an improvement technology in traditional PMMA transfer method and could be used as a long-term stable saturable absorber for the passively mode locking lasers.
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Li, Jiaheng, Yang Li, Shiqiao Du, Zun Wang, Bing-Lin Gu, Shou-Cheng Zhang, Ke He, Wenhui Duan, and Yong Xu. "Intrinsic magnetic topological insulators in van der Waals layered MnBi2Te4-family materials." Science Advances 5, no. 6 (June 2019): eaaw5685. http://dx.doi.org/10.1126/sciadv.aaw5685.

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The interplay of magnetism and topology is a key research subject in condensed matter physics, which offers great opportunities to explore emerging new physics, such as the quantum anomalous Hall (QAH) effect, axion electrodynamics, and Majorana fermions. However, these exotic physical effects have rarely been realized experimentally because of the lack of suitable working materials. Here, we predict a series of van der Waals layered MnBi2Te4-related materials that show intralayer ferromagnetic and interlayer antiferromagnetic exchange interactions. We find extremely rich topological quantum states with outstanding characteristics in MnBi2Te4, including an antiferromagnetic topological insulator with the long-sought topological axion states on the surface, a type II magnetic Weyl semimetal with one pair of Weyl points, as well as a collection of intrinsic axion insulators and QAH insulators in even- and odd-layer films, respectively. These notable predictions, if proven experimentally, could profoundly change future research and technology of topological quantum physics.
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Hu, Xiangting, Ning Mao, Hao Wang, Chengwang Niu, Baibiao Huang, and Ying Dai. "Two-dimensional ferroelastic topological insulator with tunable topological edge states in single-layer ZrAsX (X = Br and Cl)." Journal of Materials Chemistry C 7, no. 31 (2019): 9743–47. http://dx.doi.org/10.1039/c9tc02713k.

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Zhang, Jun, Zeping Peng, Ajay Soni, Yanyuan Zhao, Yi Xiong, Bo Peng, Jianbo Wang, Mildred S. Dresselhaus, and Qihua Xiong. "Raman Spectroscopy of Few-Quintuple Layer Topological Insulator Bi2Se3Nanoplatelets." Nano Letters 11, no. 6 (June 8, 2011): 2407–14. http://dx.doi.org/10.1021/nl200773n.

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Zou, Yi-Chao, Zhi-Gang Chen, Enze Zhang, Fantai Kong, Yan Lu, Lihua Wang, John Drennan, et al. "Atomic disorders in layer structured topological insulator SnBi2Te4 nanoplates." Nano Research 11, no. 2 (August 17, 2017): 696–706. http://dx.doi.org/10.1007/s12274-017-1679-z.

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Sung, Ji Ho, Hoseok Heo, Inchan Hwang, Myungsoo Lim, Donghun Lee, Kibum Kang, Hee Cheul Choi, Jae-Hoon Park, Seung-Hoon Jhi, and Moon-Ho Jo. "Atomic Layer-by-Layer Thermoelectric Conversion in Topological Insulator Bismuth/Antimony Tellurides." Nano Letters 14, no. 7 (June 18, 2014): 4030–35. http://dx.doi.org/10.1021/nl501468k.

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Dissertations / Theses on the topic "Topological insulator layer"

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Wang, Yihua. "Laser-Based Angle-Resolved Photoemission Spectroscopy of Topological Insulators." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10635.

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Topological insulators (TI) are a new phase of matter with very exotic electronic properties on their surface. As a direct consequence of the topological order, the surface electrons of TI form bands that cross the Fermi surface odd number of times and are guaranteed to be metallic. They also have a linear energy-momentum dispersion relationship that satisfies the Dirac equation and are therefore called Dirac fermions. The surface Dirac fermions of TI are spin-polarized with the direction of the spin locked to momentum and are immune from certain scatterings. These unique properties of surface electrons provide a platform for utilizing TI in future spin-based electronics and quantum computation. The surface bands of 3D TI can be directly mapped by angle-resolved photoemission spectroscopy (ARPES) and the spin polarization can be determined by spin-resolved ARPES. These types of experiments are the first to establish the 3D topological order, which demonstrates the power of ARPES in probing the surface of strongly spin-orbit coupled materials. Extensive investigation of TI has ranged from understanding the fundamental electronic and lattice structure of various TI compounds to building TI-based devices in search of more exotic particles such as Majorana fermions and magnetic monopoles. Surface-sensitive techniques that can efficiently disentangle the charge and spin degrees of freedom have been crucially important in tackling the multi-faceted problems of TI. In this thesis, I show that laser-based ARPES in combination with a time-of-flight spectrometer is a powerful tool to study the spin structure and charge dynamics of the Dirac fermions on the surface of TI. Chapter 1 gives a brief introduction of TI. Chapter 2 describes the basic principles behind ARPES and time-resolved ARPES (TrARPES). Chapter 3 provides a detailed account of the experimental setup to perform laser-based ARPES and TrARPES. In Chapters 4 and 5, how these two techniques are effectively applied to investigate two unique electronic properties of TI is elaborated. Through these studies, I have obtained a complete mapping of the spin texture of several prototypical topological insulators and have uncovered the cooling mechanism governing the hot surface Dirac fermions.
Physics
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Plank, Helene [Verfasser], and Sergey D. [Akademischer Betreuer] Ganichev. "Optoelectronic Phenomena Induced by Terahertz/Infrared Laser Radiation in Topological Insulators and Graphene / Helene Plank ; Betreuer: Sergey D. Ganichev." Regensburg : Universitätsbibliothek Regensburg, 2018. http://d-nb.info/1162339772/34.

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Jenderka, Marcus. "Pulsed Laser Deposition of Iridate and YBiO3 Thin Films." Doctoral thesis, Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-219334.

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Die vorliegende Arbeit befasst sich mit dem Dünnfilmwachstum der ternären Oxide Na2IrO3, Li2IrO3, Y2Ir2O7 und YBiO3. All diesen oxidischen Materialien ist gemein, dass sie Verwirklichungen sogenannter Topologischer Isolatoren oder Spin-Flüssigkeiten sein könnten. Diese neuartigen Materiezustände versprechen eine zukünftige Anwendung in der Quantencomputation, in magnetischen Speichern und in elektrischen Geräten mit geringer Leistungsaufnahme. Die Herstellung der hier gezeigten Dünnfilme ist daher ein erster Schritt zur Umsetzung dieser Anwendungen in der Zukunft. Alle Dünnfilme werden mittels gepulster Laserplasmaabscheidung auf verschiedenen einkristallinen Substraten hergestellt. Die strukturellen, optischen und elektrischen Eigenschaften der Filme werden mittels etablierter experimenteller Verfahren wie Röntgenbeugung, spektroskopischer Ellipsometrie und elektrischenWiderstandsmessungen untersucht. Die strukturellen Eigenschaften von erstmalig in der Masterarbeit des Authors verwirklichten Na2IrO3-Dünnfilmen können durch Abscheidung einer ZnO-Zwischenschicht deutlich verbessert werden. Einkristalline Li2IrO3-Dünnfilme mit einer definierten Kristallausrichtung werden erstmalig hergestellt. Die Messung der dielektrischen Funktion gibt Einblick in elektronische Anregungen, die gut vergleichbar mit Li2IrO3-Einkristallen und verwandten Iridaten sind. Des Weiteren wird aus den Daten eine optische Energielücke von ungefähr 300 meV bestimmt. In Y2Ir2O7-Dünnfilmen wird eine mögliche (111)-Vorzugsorientierung in Wachstumsrichtung gefunden. Im Vergleich mit der chemischen Lösungsabscheidung zeigen die hier mittels gepulster Laserplasmaabscheidung hergestellten YBiO3-Dünnfilme eine definierte, biaxiale Kristallausrichtung in der Wachstumsebene bei einer deutlich höheren Schichtdicke. Über die gemessene dielektrische Funktion können eine direkte und indirekte Bandlücke bestimmt werden. Deren Größe gibt eine notwendige experimentelle Rückmeldung an theoretische Berechnungen der elektronischen Bandstruktur von YBiO3, welche zur Vorhersage der oben erwähnten, neuartigen Materiezuständen verwendet werden. Nach einer Einleitung und Motivation dieser Arbeit gibt das zweite Kapitel einen Überblick über den gegenwärtigen Forschungsstand der hier untersuchten Materialien. Die folgenden zwei Kapitel beschreiben die Probenherstellung und die verwendeten experimentellen Untersuchungsmethoden. Anschließend werden für jedes Material einzeln die experimentellen Ergebnisse dieser Arbeit diskutiert. Die Arbeit schließt mit einer Zusammenfassung und einem Ausblick
The present thesis reports on the thin film growth of ternary oxides Na2IrO3, Li2IrO3, Y2Ir2O7 and YBiO3. All of these oxides are candidate materials for the so-called topological insulator and spin liquid, respectively. These states of matter promise future application in quantum computation, and in magnetic memory and low-power electronic devices. The realization of the thin films presented here, thus represents a first step towards these future device applications. All thin films are prepared by means of pulsed laser deposition on various single-crystalline substrates. Their structural, optical and electronic properties are investigated with established experimental methods such as X-ray diffraction, spectroscopic ellipsometry and resistivity measurements. The structural properties of Na2IrO3 thin films, that were previously realized in the author’s M. Sc. thesis for the first time, are improved significantly by deposition of an intermediate ZnO layer. Single-crystalline Li2IrO3 thin films are grown for the first time and exhibit a defined crystal orientation. Measurement of the dielectric function gives insight into electronic excitations that compare well with single crystal samples and related iridates. From the data, an optical energy gap of about 300 meV is obtained. For Y2Ir2O7 thin films, a possible (111) out-of-plane preferential crystal orientation is obtained. Compared to chemical solution deposition, the pulsed laser-deposited YBiO3 thin films presented here exhibit a biaxial in-plane crystal orientation up to a significantly larger film thickness. From the measured dielectric function, a direct and indirect band gap energy is determined. Their magnitude provides necessary experimental feedback for theoretical calculations of the electronic structure of YBiO3, which are used in the prediction of the novel states of matter mentioned above. After the introduction and motivation of this thesis, the second chapter reviews the current state of the science of the studied thin film materials. The following two chapters introduce the sample preparation and the employed experimental methods, respectively. Subsequently, the experimental results of this thesis are discussed for each material individually. The thesis concludes with a summary and an outlook
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4

Berntsen, Magnus H. "Consequences of a non-trivial band-structure topology in solids : Investigations of topological surface and interface states." Doctoral thesis, KTH, Material- och nanofysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121974.

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The development and characterization of experimental setups for angle-resolved photoelectron spectroscopy (ARPES) and spin- and angle-resolved photoelectron spectroscopy (SARPES) is described. Subsequently, the two techniques are applied to studies of the electronic band structure in topologically non-trivial materials. The laser-based ARPES setup works at a photon energy of 10.5 eV and a typical repetition rate in the range 200 kHz to 800 kHz. By using a time-of-flight electron energy analyzer electrons emitted from the sample within a solid angle of up to ±15 degrees can be collected and analyzed simultaneously. The SARPES setup is equipped with a traditional hemispherical electron energy analyzer in combination with a mini-Mott electron polarimeter. The system enables software-controlled switching between angle-resolved spin-integrated and spin-resolved measurements, thus providing the possibility to orient the sample by mapping out the electronic band structure using ARPES before performing spin-resolved measurements at selected points in the Brillouin zone. Thin films of the topological insulators (TIs) Bi2Se3, Bi2Te3 and Sb2Te3 are grown using e-beam evaporation and their surface states are observed by means of ARPES. By using a combination of low photon energies and cryogenic sample temperatures the topological states originating from both the vacuum interface (surface) and the substrate interface are observed in Bi2Se3 films and Bi2Se3/Bi2Te3 heterostructures, with total thicknesses in the ultra-thin limit (six to eight quintuple layers), grown on Bi-terminated Si(111) substrates. Band alignment between Si and Bi2Se3 at the interface creates a band bending through the films. The band bending is found to be independent of the Fermi level (EF) position in the bulk of the substrate, suggesting that the surface pinning of EF in the Si(111) substrate remains unaltered after deposition of the TI films. Therefore, the type and level of doping of the substrate does not show any large influence on the size of the band bending. Further, we provide experimental evidence for the realization of a topological crystalline insulator (TCI) phase in the narrow-band semiconductor Pb1−xSnxSe. The TCI phase exists for temperatures below the transition temperature Tc and is characterized by an inverted bulk band gap accompanied by the existence of non-gapped surface states crossing the band gap. Above Tc the material is in a topologically trivial phase where the surface states are gapped. Thus, when lowering the sample temperature across Tc a topological phase transition from a trivial insulator to a TCI is observed. SARPES studies indicate a helical spin structure of the surface states both in the topologically trivial and the TCI phase.

QC 20130507

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5

Dantscher, Kathrin-Maria [Verfasser], and Sergey D. [Akademischer Betreuer] Ganichev. "Terahertz Laser Spectroscopy of Two- and Three-Dimensional Topological Insulators based on HgTe Nanostructures / Kathrin-Maria Dantscher ; Betreuer: Sergey D. Ganichev." Regensburg : Universitätsbibliothek Regensburg, 2017. http://d-nb.info/1149366656/34.

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6

Semaan, Georges. "Soliton dynamics in fiber lasers : from dissipative soliton to dissipative soliton resonance." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0029/document.

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Dans cette thèse, nous étudions expérimentalement la génération d'impulsions carrées très énergétiques et accordable à l’échelle nanosecondes et d'impulsions ultracourtes à haute puissance moyenne de sortie dans les lasers à fibre utilisant les nanomatériaux comme absorbant saturable. Tout d'abord, puisque la dynamique des impulsions est dominée par l'interaction de la non linéarité et de la dispersion chromatique cubique de la fibre avec un mécanisme de discrimination d'intensité appelé absorbant saturable, la stabilité d'une distribution harmonique en mode verrouillé est étudiée par injection externe d'une onde continue.Enfin, nous avons utilisés des absorbant saturable à base de nanomatériaux déposés sur des tapers optiques dans les lasers à fibre pour générer des impulsions ultracourtes avec une puissance de sortie moyenne élevée
In this thesis, we investigate experimentally the generation of high energy nanosecond tunable square pulses and high output power ultrashort pulses in fiber lasers. First, since pulse dynamics are dominated by the interaction of the fiber's cubic Kerr nonlinearity and chromatic dispersion with an intensity-discriminating mechanism referred to as a saturable absorber, the stability of a harmonic mode-locked distribution is studied by external injection of a continuous wave. Finally, we implemented nanomaterial based saturable absorbers in fiber laser configuration to generate ultrashort pulses with high average output power. Different techniques of achieving such components are explicitly detailed: ultrashort pulse generation in ring cavities where graphene and topological insulators are deposited on optical tapers to form a saturable absorber
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7

Zhi-JieLu and 盧致傑. "Studies of physical properties of topological insulator and ordinary insulator Sb2Se3-Bi2Se3 multiple layer grown by MBE." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/4y7tb4.

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8

Chou, Che-min, and 周哲民. "Pulsed Solid-State Laser Using Topological Insulator Bi2Te3 Saturable Absorber." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/6f7x55.

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碩士
國立中山大學
光電工程學系研究所
103
In this thesis, the characteristics of high power solid-state pulsed laser by using topological insulator Bi2Te3 saturable absorber were investigated. First, the high yield of Bi2Te3 nanosheets were successfully fabricated by hydrothermal exfoliation, which had been certificated with X-ray diffraction, raman spectrum characterizations, energy-dispersive X-ray spectroscopy, atomic force microscopy, scanning electron microscopy, and transmission electron microscopy. All the results confirms anvantanges and feasibility of convient route for producing saturable absorber. This is beneficial to further commercial solid-state laser applications. In addition, we demonstarted passive solid-state pulsed laser by exfoliated topological insulators Bi2Te3 and reliazed stable Q-switching operation by folded resonator in order to prevent residual pumping power. The obtained pulse energy is over than 5 μJ at 1.06 µm. This is the greatest value in TI-based solid-state laser to our best knowledgement. Finally, by virtue of improved resonator, the optimized Q-switching performances compare favorably with different coverage of saturable absorber at 1.06 µm and 1.34 µm. We have experimentally demonstrated that output power of 326 mW、pulse energy of 2.8 μJ and pulse duration of 673 ns at 1.34 µm waveband. Furthermore, we have displayed the influence of thermal effect on saturable absorber within resonator for the first time. By analysing the analogue process of beam waist and transforming the position of saturable saturaber within resonator, it will reach the higher pulse power and energy on account of contributions to more topological insulators. Moreover, we oberserved that low threshold characteristics of topological insulators as fast saturable absorber accompanied with increasing pumping power would lead to excessively high repetition rate. Above following discussion, Q-switching pulsed operation would convert into condition of continuous wave when it raised up to certain level of pumping power
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Lan-ShengYang and 楊蘭勝. "Growth and Characterization of Topological Insulator Bi2Te3 and Sb2Te3 Thin Films On Al2O3(0001) by Pulsed Laser Deposition." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/03755231247102062943.

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Jenderka, Marcus. "Pulsed Laser Deposition of Iridate and YBiO3 Thin Films." Doctoral thesis, 2016. https://ul.qucosa.de/id/qucosa%3A15345.

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Die vorliegende Arbeit befasst sich mit dem Dünnfilmwachstum der ternären Oxide Na2IrO3, Li2IrO3, Y2Ir2O7 und YBiO3. All diesen oxidischen Materialien ist gemein, dass sie Verwirklichungen sogenannter Topologischer Isolatoren oder Spin-Flüssigkeiten sein könnten. Diese neuartigen Materiezustände versprechen eine zukünftige Anwendung in der Quantencomputation, in magnetischen Speichern und in elektrischen Geräten mit geringer Leistungsaufnahme. Die Herstellung der hier gezeigten Dünnfilme ist daher ein erster Schritt zur Umsetzung dieser Anwendungen in der Zukunft. Alle Dünnfilme werden mittels gepulster Laserplasmaabscheidung auf verschiedenen einkristallinen Substraten hergestellt. Die strukturellen, optischen und elektrischen Eigenschaften der Filme werden mittels etablierter experimenteller Verfahren wie Röntgenbeugung, spektroskopischer Ellipsometrie und elektrischenWiderstandsmessungen untersucht. Die strukturellen Eigenschaften von erstmalig in der Masterarbeit des Authors verwirklichten Na2IrO3-Dünnfilmen können durch Abscheidung einer ZnO-Zwischenschicht deutlich verbessert werden. Einkristalline Li2IrO3-Dünnfilme mit einer definierten Kristallausrichtung werden erstmalig hergestellt. Die Messung der dielektrischen Funktion gibt Einblick in elektronische Anregungen, die gut vergleichbar mit Li2IrO3-Einkristallen und verwandten Iridaten sind. Des Weiteren wird aus den Daten eine optische Energielücke von ungefähr 300 meV bestimmt. In Y2Ir2O7-Dünnfilmen wird eine mögliche (111)-Vorzugsorientierung in Wachstumsrichtung gefunden. Im Vergleich mit der chemischen Lösungsabscheidung zeigen die hier mittels gepulster Laserplasmaabscheidung hergestellten YBiO3-Dünnfilme eine definierte, biaxiale Kristallausrichtung in der Wachstumsebene bei einer deutlich höheren Schichtdicke. Über die gemessene dielektrische Funktion können eine direkte und indirekte Bandlücke bestimmt werden. Deren Größe gibt eine notwendige experimentelle Rückmeldung an theoretische Berechnungen der elektronischen Bandstruktur von YBiO3, welche zur Vorhersage der oben erwähnten, neuartigen Materiezuständen verwendet werden. Nach einer Einleitung und Motivation dieser Arbeit gibt das zweite Kapitel einen Überblick über den gegenwärtigen Forschungsstand der hier untersuchten Materialien. Die folgenden zwei Kapitel beschreiben die Probenherstellung und die verwendeten experimentellen Untersuchungsmethoden. Anschließend werden für jedes Material einzeln die experimentellen Ergebnisse dieser Arbeit diskutiert. Die Arbeit schließt mit einer Zusammenfassung und einem Ausblick.
The present thesis reports on the thin film growth of ternary oxides Na2IrO3, Li2IrO3, Y2Ir2O7 and YBiO3. All of these oxides are candidate materials for the so-called topological insulator and spin liquid, respectively. These states of matter promise future application in quantum computation, and in magnetic memory and low-power electronic devices. The realization of the thin films presented here, thus represents a first step towards these future device applications. All thin films are prepared by means of pulsed laser deposition on various single-crystalline substrates. Their structural, optical and electronic properties are investigated with established experimental methods such as X-ray diffraction, spectroscopic ellipsometry and resistivity measurements. The structural properties of Na2IrO3 thin films, that were previously realized in the author’s M. Sc. thesis for the first time, are improved significantly by deposition of an intermediate ZnO layer. Single-crystalline Li2IrO3 thin films are grown for the first time and exhibit a defined crystal orientation. Measurement of the dielectric function gives insight into electronic excitations that compare well with single crystal samples and related iridates. From the data, an optical energy gap of about 300 meV is obtained. For Y2Ir2O7 thin films, a possible (111) out-of-plane preferential crystal orientation is obtained. Compared to chemical solution deposition, the pulsed laser-deposited YBiO3 thin films presented here exhibit a biaxial in-plane crystal orientation up to a significantly larger film thickness. From the measured dielectric function, a direct and indirect band gap energy is determined. Their magnitude provides necessary experimental feedback for theoretical calculations of the electronic structure of YBiO3, which are used in the prediction of the novel states of matter mentioned above. After the introduction and motivation of this thesis, the second chapter reviews the current state of the science of the studied thin film materials. The following two chapters introduce the sample preparation and the employed experimental methods, respectively. Subsequently, the experimental results of this thesis are discussed for each material individually. The thesis concludes with a summary and an outlook.
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Books on the topic "Topological insulator layer"

1

A, Balandin Alexander, and Materials Research Society Meeting, eds. Functional two-dimensional layered materials, from graphene to topological insulators: Symposium held April 25-29, 2011, San Francisco, California, U.S.A. Warrendale, Pa: Materials Research Society, 2012.

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2

Murakami, S., and T. Yokoyama. Quantum spin Hall effect and topological insulators. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198787075.003.0017.

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This chapter begins with a description of quantum spin Hall systems, or topological insulators, which embody a new quantum state of matter theoretically proposed in 2005 and experimentally observed later on using various methods. Topological insulators can be realized in both two dimensions (2D) and in three dimensions (3D), and are nonmagnetic insulators in the bulk that possess gapless edge states (2D) or surface states (3D). These edge/surface states carry pure spin current and are sometimes called helical. The novel property for these edge/surface states is that they originate from bulk topological order, and are robust against nonmagnetic disorder. The following sections then explain how topological insulators are related to other spin-transport phenomena.
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Book chapters on the topic "Topological insulator layer"

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Kim, Heejae. "Topological Invariants and Tight-Binding Models from the Layer Constructions." In Glide-Symmetric Z2 Magnetic Topological Crystalline Insulators, 99–137. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9077-8_5.

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Nanni, Luca. "Computational Inference of DNA Folding Principles: From Data Management to Machine Learning." In Special Topics in Information Technology, 79–88. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-85918-3_7.

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AbstractDNA is the molecular basis of life and would total about three meters if linearly untangled. To fit in the cell nucleus at the micrometer scale, DNA has, therefore, to fold itself into several layers of hierarchical structures, which are thought to be associated with functional compartmentalization of genomic features like genes and their regulatory elements. For this reason, understanding the mechanisms of genome folding is a major biological research problem. Studying chromatin conformation requires high computational resources and complex data analyses pipelines. In this chapter, we first present the PyGMQL software for interactive and scalable data exploration for genomic data. PyGMQL allows the user to inspect genomic datasets and design complex analysis pipelines. The software presents itself as a easy-to-use Python library and interacts seamlessly with other data analysis packages. We then use the software for the study of chromatin conformation data. We focus on the epigenetic determinants of Topologically Associating Domains (TADs), which are region of high self chromatin interaction. The results of this study highlight the existence of a “grammar of genome folding” which dictates the formation of TADs and boundaries, which is based on the CTCF insulator protein. Finally we focus on the relationship between chromatin conformation and gene expression, designing a graph representation learning model for the prediction of gene co-expression from gene topological features obtained from chromatin conformation data. We demonstrate a correlation between chromatin topology and co-expression, shedding a new light on this debated topic and providing a novel computational framework for the study of co-expression networks.
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DMITRIEV, A. Y., N. I. FEDOTOV, V. F. NASRETDINOVA, and S. V. ZAITSEV-ZOTOV. "SCANNING TUNNELING SPECTROSCOPY OF QUINTUPLE-LAYER STEPS ON THE SURFACE OF Bi2Se3 TOPOLOGICAL INSULATOR." In Physics, Chemistry and Applications of Nanostructures, 140–43. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814696524_0036.

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Le, Phuoc Huu, and Chih Wei Luo. "Thermoelectric and Topological Insulator Bismuth Chalcogenide Thin Films Grown Using Pulsed Laser Deposition." In Applications of Laser Ablation - Thin Film Deposition, Nanomaterial Synthesis and Surface Modification. InTech, 2016. http://dx.doi.org/10.5772/65898.

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Thambiratnam, Kavintheran, Norazriena Yusoff, Siti Aisyah Reduan, Muhamad Zharif Samion, Shok Ing Ooi, and Harith Ahmad. "Two-Dimensional Materials for Advancement of Fiber Laser Technologies." In Photonic Materials: Recent Advances and Emerging Applications, 177–213. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815049756123010013.

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Two-dimensional (2D) materials such as graphene, chalcogenides, topological insulators, black phosphorus, and MXenes have of late become the focus of intense research efforts due to the excellent and unique optoelectrical properties these materials possess. This is due to the unique properties these materials possess, such as tunable bandgaps, high mobility in the energy bandgap, third-order nonlinearity, and nonlinear absorption that can be tailored to suit the specific needs of different optical applications. These properties have allowed for the development of fiber optic-based pulsed laser systems with better integration and flexibility capabilities as well as improved performance as compared to their bulk counterparts. In this chapter, the development of optical fiber pulsed lasers that incorporate selected 2D materials, particularly 2D chalcogenides that encompass metal monochalcogenides (MMs), and traditional metal dichalcogenides (TMDs) and MXenes is reviewed. This chapter will cover the fundamental aspects of the aforementioned materials, the operating principles of Q-switching and mode-locking, and the configuration of these 2D materials as saturable absorbers (SAs). The main section of this chapter will focus on the current status of the development of Q-switched and mode-locked optical fiber laser systems using 2D material-based SAs. Finally, the chapter will explore the perspectives and challenges on the future of the potential applications of these 2D materials in pulsed optical systems.
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Jarillo-Herrero, Pablo, and Adolfo Plasencia. "Graphene and Its “Family”: The Finest Materials Ever to Exist." In Is the Universe a Hologram? The MIT Press, 2017. http://dx.doi.org/10.7551/mitpress/9780262036016.003.0006.

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In this dialogue, the physicist Pablo Jarillo-Herrero outlines his scientific career path, which started out in theoretical high-energy physics on a cosmological scale. Later he was drawn to experimental science and condensed material physics, which is his current area of research. He talks about his intense relationship with mathematics, only surpassed by his passion for physics, and their connection with experiment and reality—the first thing he looks for. Pablo goes on to reflect on how philosophers can help to bring a perspective to many issues related to quantum physics. He believes that physicists of today should be open to the possibility that what seems to be impossible may be possible. He moves on to discuss his current research with graphene and its two-dimensional ‘family’ of materials. This research also includes the quantum transport of electrons, topological insulators, and the ‘ultra-relativistic’ behavior of particles inside these materials; the finest materials to have ever or are ever likely to exist.
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Conference papers on the topic "Topological insulator layer"

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Norimatsu, Katsura, Shin-ichi Uozumi, Shingo Hayashi, Kyushiro Igarashi, Shuhei Yamamoto, Takao Sasagawa, and Kazutaka G. Nakamura. "Ultrafast Phonon Dynamics in Few-quintuple layer Topological Insulator Sb2Te3." In International Conference on Ultrafast Phenomena. Washington, D.C.: OSA, 2014. http://dx.doi.org/10.1364/up.2014.07.mon.p1.44.

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Lv, Yang, James Kally, Delin Zhang, Joon Sue Lee, Mahdi Jamali, Nitin Samarth, and Jian-Ping Wang. "Unidirectional spin Hall and Rashba-Edelstein magnetoresistance in topological insulator-ferromagnet layer heterostructures (Conference Presentation)." In Spintronics XI, edited by Henri Jaffrès, Henri-Jean Drouhin, Jean-Eric Wegrowe, and Manijeh Razeghi. SPIE, 2018. http://dx.doi.org/10.1117/12.2323329.

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Bandres, Miguel A., Steffen Wittek, Gal Harari, Midya Parto, Jinhan Ren, Mordechai Segev, Demetrios N. Christodoulides, and Mercedeh Khajavikhan. "Topological Insulator Laser." In Frontiers in Optics. Washington, D.C.: OSA, 2018. http://dx.doi.org/10.1364/fio.2018.ftu4c.1.

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Harari, G., M. A. Bandres, S. Wittek, M. Parto, Demetri N. Christodoulides, Mercedeh Khajavikhan, and Mordechai Segev. "Topological Insulator Laser." In 2019 24th Microoptics Conference (MOC). IEEE, 2019. http://dx.doi.org/10.23919/moc46630.2019.8982765.

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Lustig, Eran, Lukas J. Maczewsky, Julius Beck, Tobias Biesenthal, Matthias Heinrich, Zhaoju Yang, Yonatan Plotnik, Alexander Szameit, and Mordechai Segev. "Three-dimensional photonic topological insulator induced by lattice dislocations." In Laser Science. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/ls.2022.lm1f.3.

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We experimentally demonstrate three-dimensional photonic topological insulators induced by lattice dislocations. We observe topological protected surface states, as well as light propagating unidirectionally along a screw dislocation.
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Hsieh, D., James McIver, Y. H. Wang, L. Fu, D. R. Gardner, Y. S. Lee, and N. Gedik. "Ultrafast Optical Probing of Topological Insulators." In Laser Science. Washington, D.C.: OSA, 2011. http://dx.doi.org/10.1364/ls.2011.lwj3.

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Segev, Mordechai, Miguel A. Bandres, Gal Harari, Yonatan Plotnik, Hanan Herzig-Sheinfux, Eran Lustig, Rivka Bekenstein, and Mikael C. Rechtsman. "New Ideas on Photonic Topological Insulators." In Laser Science. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/ls.2016.lf5i.3.

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Khanikaev, Alexander B. "All-dielectric photonic topological insulators and metasurfaces." In Laser Science. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/ls.2016.lf5i.2.

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Dikopoltsev, Alex, Tristan H. Harder, Eran Lustig, Oleg A. Egorov, Johannes Beierlein, Adriana Wolf, Monika Emmerling, et al. "Topological insulator vertically-emitting laser array." In CLEO: QELS_Fundamental Science. Washington, D.C.: OSA, 2021. http://dx.doi.org/10.1364/cleo_qels.2021.fth4h.1.

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Wang, Mingjun, Niuniu Lin, Yanxiang Liu, and Shenhe Ren. "Intensity distribution of vortex beams from multilayered topological insulator slab." In Advanced Laser Materials and Laser Technology, edited by Pu Zhou, Jian Zhang, Takunori Taira, Wenxue Li, and Shibin Jiang. SPIE, 2019. http://dx.doi.org/10.1117/12.2542898.

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You might also be interested in the extended bibliographies on the topic 'Topological insulator layer' for particular source types:
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