Thematische Bibliographien / Topological semimetals

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Auswahl der wissenschaftlichen Literatur zum Thema „Topological semimetals“

Autor: Grafiati

Veröffentlicht am 25. Mai 2024

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Zeitschriftenartikel zum Thema "Topological semimetals"

Gao, Heng, Jörn W. F. Venderbos, Youngkuk Kim und Andrew M. Rappe. „Topological Semimetals from First Principles“. Annual Review of Materials Research 49, Nr. 1 (Juli 2019): 153–83. http://dx.doi.org/10.1146/annurev-matsci-070218-010049.

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We review recent theoretical progress in the understanding and prediction of novel topological semimetals. Topological semimetals define a class of gapless electronic phases exhibiting topologically stable crossings of energy bands. Different types of topological semimetals can be distinguished on the basis of the degeneracy of the band crossings, their codimension (e.g., point or line nodes), and the crystal space group symmetries on which the protection of stable band crossings relies. The dispersion near the band crossing is a further discriminating characteristic. These properties give rise to a wide range of distinct semimetal phases such as Dirac or Weyl semimetals, point or line node semimetals, and type I or type II semimetals. In this review we give a general description of various families of topological semimetals, with an emphasis on proposed material realizations from first-principles calculations. The conceptual framework for studying topological gapless electronic phases is reviewed, with a particular focus on the symmetry requirements of energy band crossings, and the relation between the different families of topological semimetals is elucidated. In addition to the paradigmatic Dirac and Weyl semimetals, we pay particular attention to more recent examples of topological semimetals, which include nodal line semimetals, multifold fermion semimetals, and triple-point semimetals. Less emphasis is placed on their surface state properties, their responses to external probes, and recent experimental developments.

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Hu, Jin, Su-Yang Xu, Ni Ni und Zhiqiang Mao. „Transport of Topological Semimetals“. Annual Review of Materials Research 49, Nr. 1 (Juli 2019): 207–52. http://dx.doi.org/10.1146/annurev-matsci-070218-010023.

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Three-dimensional (3D) topological semimetals represent a new class of topological matters. The study of this family of materials has been at the frontiers of condensed matter physics, and many breakthroughs have been made. Several topological semimetal phases, including Dirac semimetals (DSMs), Weyl semimetals (WSMs), nodal-line semimetals (NLSMs), and triple-point semimetals, have been theoretically predicted and experimentally demonstrated. The low-energy excitation around the Dirac/Weyl nodal points, nodal line, or triply degenerated nodal point can be viewed as emergent relativistic fermions. Experimental studies have shown that relativistic fermions can result in a rich variety of exotic transport properties, e.g., extremely large magnetoresistance, the chiral anomaly, and the intrinsic anomalous Hall effect. In this review, we first briefly introduce band structural characteristics of each topological semimetal phase, then review the current studies on quantum oscillations and exotic transport properties of various topological semimetals, and finally provide a perspective of this area.

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Ominato, Yuya, Ai Yamakage und Kentaro Nomura. „Electric Polarization in Magnetic Topological Nodal Semimetal Thin Films“. Condensed Matter 3, Nr. 4 (30.11.2018): 43. http://dx.doi.org/10.3390/condmat3040043.

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We theoretically study the electric polarization in magnetic topological nodal semimetal thin films. In magnetically doped topological insulators, topological nodal semimetal phases emerge once the exchange coupling overcomes the band gap. Changing the magnetization direction, nodal structure is modulated and the system becomes topological nodal point or line semimetals. We find that nodal line semimetals are characterized by non-linear electric polarization, which is not observed in nodal point semimetals. The non-linear response originates from the existence of the surface states. Screening effect is self consistently included within a mean field approximation and the non-linear electric polarization is observed even in the presence of screening effect.

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Nie, Simin, Gang Xu, Fritz B. Prinz und Shou-cheng Zhang. „Topological semimetal in honeycomb lattice LnSI“. Proceedings of the National Academy of Sciences 114, Nr. 40 (19.09.2017): 10596–600. http://dx.doi.org/10.1073/pnas.1713261114.

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Recognized as elementary particles in the standard model, Weyl fermions in condensed matter have received growing attention. However, most of the previously reported Weyl semimetals exhibit rather complicated electronic structures that, in turn, may have raised questions regarding the underlying physics. Here, we report promising topological phases that can be realized in specific honeycomb lattices, including ideal Weyl semimetal structures, 3D strong topological insulators, and nodal-line semimetal configurations. In particular, we highlight a semimetal featuring both Weyl nodes and nodal lines. Guided by this model, we showed that GdSI, the long-perceived ideal Weyl semimetal, has two pairs of Weyl nodes residing at the Fermi level and that LuSI (YSI) is a 3D strong topological insulator with the right-handed helical surface states. Our work provides a mechanism to study topological semimetals and proposes a platform for exploring the physics of Weyl semimetals as well as related device designs.

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Xu, Su-Yang, Ilya Belopolski, Daniel S. Sanchez, Chenglong Zhang, Guoqing Chang, Cheng Guo, Guang Bian et al. „Experimental discovery of a topological Weyl semimetal state in TaP“. Science Advances 1, Nr. 10 (November 2015): e1501092. http://dx.doi.org/10.1126/sciadv.1501092.

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Weyl semimetals are expected to open up new horizons in physics and materials science because they provide the first realization of Weyl fermions and exhibit protected Fermi arc surface states. However, they had been found to be extremely rare in nature. Recently, a family of compounds, consisting of tantalum arsenide, tantalum phosphide (TaP), niobium arsenide, and niobium phosphide, was predicted as a Weyl semimetal candidates. We experimentally realize a Weyl semimetal state in TaP. Using photoemission spectroscopy, we directly observe the Weyl fermion cones and nodes in the bulk, and the Fermi arcs on the surface. Moreover, we find that the surface states show an unexpectedly rich structure, including both topological Fermi arcs and several topologically trivial closed contours in the vicinity of the Weyl points, which provides a promising platform to study the interplay between topological and trivial surface states on a Weyl semimetal’s surface. We directly demonstrate the bulk-boundary correspondence and establish the topologically nontrivial nature of the Weyl semimetal state in TaP, by resolving the net number of chiral edge modes on a closed path that encloses the Weyl node. This also provides, for the first time, an experimentally practical approach to demonstrating a bulk Weyl fermion from a surface state dispersion measured in photoemission.

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Chu, Chun-Guang, An-Qi Wang und Zhi-Min Liao. „Josephson effect in topological semimetal-superconductor heterojunctions“. Acta Physica Sinica 72, Nr. 8 (2023): 087401. http://dx.doi.org/10.7498/aps.72.20230397.

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Topological semimetals are exotic phases of quantum matter with gapless electronic excitation protected by symmetry. Benefitting from its unique relativistic band dispersion, topological semimetals host abundant quantum states and quantum effects, esuch as Fermi-arc surface states and chiral anomaly. In recent years, due to the potential application in topological quantum computing, the hybrid system of topology and superconductivity has aroused wide interest in the community. Recent experimental progress of topological semimetal-superconductor heterojunctions is reviewed in two aspects: 1) Josephson current as a mode filter of different topological quantum states; 2) detection and manipulation of topological superconductivity and Majorana zero modes. For the former, utilizing Josephson interference, ballistic transport of Fermi-arc surface states is revealed, higher-order topological phases are discovered, and finite-momentum Cooper pairing and superconducting diode effect are realized. For the latter, by detecting a.c. Josephson effect in Dirac semimetal, the 4π-periodic supercurrent is discovered. By all-electric gate control, the topological transition of superconductivity is obtained. Outlooks of future research on topological semimetal-superconductor heterojunctions and their application in Majorana braiding and topological quantum computing are discussed.

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Chen, Guifeng, Bolin Long, Lei Jin, Hui Zhang, Zishuang Cheng, Xiaoming Zhang und Guodong Liu. „Synthesis of Weyl Semi-Metal Co3Sn2S2 by Hydrothermal Method and Its Physical Properties“. Metals 12, Nr. 5 (11.05.2022): 830. http://dx.doi.org/10.3390/met12050830.

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In the field of condensed matter physics, as new quantum materials, topological semimetals have a special topological energy band structure and nontrivial band crossings in the energy band, which will have many excellent topological properties, such as internal insulation of topological insulators and the presence of conduction electrons on the surface; this makes topological semimetals exhibit wider application prospects in electronic devices. So far, the experimental synthesis of topological semimetals was performed using physical methods to synthesize bulk single crystals, which is not conducive to the commercial application of micro and small devices. Weyl semimetal Co3Sn2S2 with shandite structure was successfully synthesized experimentally by a green and environmentally friendly hydrothermal method. Adjusting its reaction temperature, molar atomic ratio of elements and annealing temperature, and other experimental conditions, we analyze the crystal structure and physical properties of Co3Sn2S2, with the nanocrystal size being about 200 nm. We found that the Co3Sn2S2 synthesized by the hydrothermal method has a Curie temperature at 100 K to undergo ferromagnetic transition.

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Chang, Guoqing, Su-Yang Xu, Daniel S. Sanchez, Shin-Ming Huang, Chi-Cheng Lee, Tay-Rong Chang, Guang Bian et al. „A strongly robust type II Weyl fermion semimetal state in Ta3S2“. Science Advances 2, Nr. 6 (Juni 2016): e1600295. http://dx.doi.org/10.1126/sciadv.1600295.

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Weyl semimetals are of great interest because they provide the first realization of the Weyl fermion, exhibit exotic quantum anomalies, and host Fermi arc surface states. The separation between Weyl nodes of opposite chirality gives a measure of the robustness of the Weyl semimetal state. To exploit the novel phenomena that arise from Weyl fermions in applications, it is crucially important to find robust separated Weyl nodes. We propose a methodology to design robust Weyl semimetals with well-separated Weyl nodes. Using this methodology as a guideline, we search among the material parameter space and identify by far the most robust and ideal Weyl semimetal candidate in the single-crystalline compound tantalum sulfide (Ta3S2) with new and novel properties beyond TaAs. Crucially, our results show that Ta3S2has the largestk-space separation between Weyl nodes among known Weyl semimetal candidates, which is about twice larger than the measured value in TaAs and 20 times larger than the predicted value in WTe2. Moreover, all Weyl nodes in Ta3S2are of type II. Therefore, Ta3S2is a type II Weyl semimetal. Furthermore, we predict that increasing the lattice by <4% can annihilate all Weyl nodes, driving a novel topological metal-to-insulator transition from a Weyl semimetal state to a topological insulator state. The robust type II Weyl semimetal state and the topological metal-to-insulator transition in Ta3S2are potentially useful in device applications. Our methodology can be generally applied to search for new Weyl semimetals.

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Burkov, A. A. „Topological semimetals“. Nature Materials 15, Nr. 11 (25.10.2016): 1145–48. http://dx.doi.org/10.1038/nmat4788.

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Chen, M. N., W. C. Chen und Yu Zhou. „Topological hybrid semimetal phases and anomalous Hall effects in a three dimensional magnetic topological insulator“. Journal of Physics: Condensed Matter 34, Nr. 2 (28.10.2021): 025502. http://dx.doi.org/10.1088/1361-648x/ac2ed7.

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Abstract In this work, we propose a ferromagnetic Bi2Se3 as a candidate to hold the coexistence of Weyl- and nodal-line semimetal phases, which breaks the time reversal symmetry. We demonstrate that the type-I Weyl semimetal phase, type-I-, type-II- and their hybrid nodal-line semimetal phases can arise by tuning the Zeeman exchange field strength and the Fermi velocity. Their topological responses under U(1) gauge field are also discussed. Our results raise a new way for realizing Weyl and nodal-line semimetals and will be helpful in understanding the topological transport phenomena in three-dimensional material systems.

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Dissertationen zum Thema "Topological semimetals"

Villanova, John William. „Examining Topological Insulators and Topological Semimetals Using First Principles Calculations“. Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/82959.

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The importance and promise that topological materials hold has been recently underscored by the award of the Nobel Prize in Physics in 2016 ``for theoretical discoveries of topological phase transitions and topological phases of matter." This dissertation explores the novel qualities and useful topologically protected surface states of topological insulators and semimetals. Topological materials have protected qualities which are not removed by weak perturbations. The manifestations of these qualities in topological insulators are spin-momentum-locked surface states, and in Weyl and Dirac semimetals they are unconventional open surface states (Fermi arcs) with anomalous electrical transport properties. There is great promise in utilizing the topologically protected surface states in electronics of the future, including spintronics, quantum computers, and highly sensitive devices. Physicists and chemists are also interested in the fundamental physics and exotic fermions exhibited in topological materials and in heterostructures including them. Chapter 1 provides an introduction to the concepts and methods of topological band theory. Chapter 2 investigates the spin and spin-orbital texture and electronic structures of the surface states at side surfaces of a topological insulator, Bi2Se3, by using slab models within density functional theory. Two representative, experimentally achieved surfaces are examined, and it is shown that careful consideration of the crystal symmetry is necessary to understand the physics of the surface state Dirac cones at these surfaces. This advances the existing literature by properly taking into account surface relaxation and symmetry beyond what is contained in effective bulk model Hamiltonians. Chapter 3 examines the Fermi arcs of a topological Dirac semimetal (DSM) in the presence of asymmetric charge transfer, of the kind which would be present in heterostructures. Asymmetric charge transfer allows one to accurately identify the projections of Dirac nodes despite the existence of a band gap and to engineer the properties of the Fermi arcs, including spin texture. Chapter 4 investigates the effect of an external magnetic field applied to a DSM. The breaking of time reversal symmetry splits the Dirac nodes into topologically charged Weyl nodes which exhibit Fermi arcs as well as conventionally-closed surface states as one varies the chemical potential.
Ph. D.

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Osterhoudt, Gavin Barnes. „Spectroscopy of Topological Materials:“. Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:109002.

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Thesis advisor: Kenneth S. Burch
Since their first experimental realizations in the 2000s, bulk electronic topological materials have been one of the most actively studied areas of condensed matter physics. Among the more recently discovered classes of topological materials are the Weyl semimetals whose low energy excitations behave like massless, relativistic particles with well-defined chirality. These material systems display exotic behavior such as surface Fermi arc states, and the chiral anomaly in which parallel magnetic and electric fields lead to an imbalance of left- and right-handed particles. Much of the research into these materials has focused on the electronic properties, but relatively little has been directed towards understanding the vibrational properties of these systems, or of the interplay between the electronic and vibrational degrees of freedom. Further, the technological potential of these materials is still underdeveloped, with the search for physical properties enhanced by the topological nature of these materials being sought after. In this dissertation we address both of these issues. In Chapters III and IV we present temperature dependent Raman investigations of the the Weyl semimetals WP2, NbAs, and TaAs. Measurements of the optical phonon linewidths are used to identify the available phonon decay paths, with ab-initio calculations and group theory used to aid the interpretation of these results. We find that some phonons display linewidths indicative of dominant decay into electron-hole pairs near the Fermi surface, rather than decay into acoustic phonons. In light of these results we discuss the role of phonon-electron coupling in the transport properties of these Weyl semimetals. In Chapter V, we discuss the construction of our "PVIC" setup for the measurement of nonlinear photocurrents. We discuss the experimental capabilities that the system was designed to possess, the operating principles behind key components of the system, and give examples of the operating procedures for using the setup. The penultimate chapter, Chapter VI, presents the results of photocurrent measurements using this setup on the Weyl semimetal TaAs. Through careful analysis of the photocurrent polarization dependence, we identify a colossal bulk photovoltaic effect in this material which exceeds the response displayed by previously studied materials by an order of magnitude. Calculations of the second-order optical conductivity tensor show that this result is consistent with the divergent Berry connection of the Weyl nodes in TaAs. In addition to these topics, Chapter II addresses the results of Raman measurements on thin film heterostructures of the topological insulator Bi2Se3 and the magnetic semiconductor EuS. By investigating the paramagnetic Raman signal in films with different compositions of EuS and Bi2Se3 we provide indirect evidence of charge transfer between the two layers. We also track the evolution of phonon energies with varying film thicknesses on multiple substrates which provides insight into the interfacial strain between layers. We conclude the dissertation in Chapter VII with a summary of the main results from each preceding chapter, and give suggestions for future experiments that further investigate these topics
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Physics

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Zhong, Shudan. „Linear and Nonlinear Electromagnetic Responses in Topological Semimetals“. Thesis, University of California, Berkeley, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13421373.

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The topological consequences of time reversal symmetry breaking in two dimensional electronic systems have been a focus of interest since the discovery of the quantum Hall effects. Similarly interesting phenomena arise from breaking inversion symmetry in three dimensional systems. For example, in Dirac and Weyl semimetals the inversion symmetry breaking allows for non-trivial topological states that contain symmetry-protected pairs of chiral gapless fermions. This thesis presents our work on the linear and nonlinear electromagnetic responses in topological semimetals using both a semiclassical Boltzmann equation approach and a full quantum mechanical approach. In the linear response, we find a ``gyrotropic magnetic effect" (GME) where the current density $j

B$ in a clean metal is induced by a slowly-varying magnetic field. It is shown that the experimental implications and microscopic origin of GME are both very different from the chiral magnetic effect (CME). We develop a systematic way to study general nonlinear electromagnetic responses in the low-frequency limit using a Floquet approach and we use it to study the circular photogalvanic effect (CPGE) and second-harmonic generation (SHG). Moreover, we derive a semiclassical formula for magnetoresistance in the weak field regime, which includes both the Berry curvature and the orbital magnetic moment. Our semiclassical result may explain the recent experimental observations on topological semimetals. In the end, we present our work on the Hall conductivity of insulators in a static inhomogeneous electric field and we discuss its relation to Hall viscosity.

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Chu, Ruilin, und 储瑞林. „Numerical study of topological insulators and semi-metals“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47163252.

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Topological insulators(TIs) constitute a novel state of quantum matter which possesses non-trivial topological properties. Although discovered only in the recent few years, TIs have attracted intensive interest among the community of condensed matter physics and material science. TIs are insulating in the bulk but have conductive gapless edge or surface states on the boundaries, which have their origin in the nontrivial bulk band topology that is induced by the strong spin-orbital interactions in the materials. Existing in all dimensions, TIs exhibit a variety of exotic physics such as quantum spin Hall effect, momentum-spin locked surface states, Dirac fermion transport, quantized anomalous Hall effect, Majorana fermions, etc. In this thesis, I study the transport properties of 2D and 3D TIs by numerical approaches. As an introduction, a brief review of TIs is given. A detailed description of the numerical methods is also presented. The results can be summarized in four aspects. First, disorder is found be able to induce a non-trivial TI from an originally trivial band insulator, where the conductance of a two terminal device drops to nearly zero and then rises to form an anomalous plateau as disorder strength is increased, and finally all the states become localized. The real space Chern number calculation as well as the effective medium theory suggests that disorder is fundamentally responsible for the emerging of the extended helical edge states in this system. We also present a levitation and pair annihilation picture of the extended states for this model. Second, by making the 2D TIs into singly connected quantum point contacts(QPCs), I show a coherent and fast Aharonov-Bohm oscillation of conductance caused by the quantum interference of the helical edge states. This oscillation not only happens against weak magnetic field but also against the gate voltage in the zero-field condition. This results in a giant edge magnetoresistance of the device in weak magnetic fields. The amplitude of the magnetoresistance is controllable by adjusting either the QPCs' slit width or the interference loop size in the device. The oscillation is found robust against disorder. Third, by applying a uniform spin-splitting Zeeman field in the bulk of the 3D TI whose surface states can be viewed as massless Dirac fermions, I find chiral edge states on the gapped surfaces of the 3D TI, which can be considered as interface states between domains of massive and massless Dirac fermions. Effectively these states are result of splitting of a perfect interface conducting channel. This picture is confirmed by the Landauer-B?ttiker calculations in four-terminal Hall bars. Finally, I propose the concept of topological semi-metals. By calculating the local density of states on the surfaces, I demonstrate that surface states and the gapless Dirac cone already exist in the system although the bulk is not gapped. We show how the uni-axial strain induces an insulating band gap and turn the semi-metal into true TI. We predict existence of quantum spin Hall effect in the thin films made of these materials, which can be significantly enhanced by disorders.
published_or_final_version
Physics
Doctoral
Doctor of Philosophy

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Mao, Ting, und 毛汀. „Theoretical studies of topological DIII-class chains and Weyl semimetals / y Ting Mao, MSci. Nanjing University“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2015. http://hdl.handle.net/10722/212613.

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Topological insulators and superconductors, which are featured by not only the topological characteristics of their gapped bulk band structure but also the special edge or surface states, have attracted great attention in the past few years. A complete classification of topological insulators and superconductors in terms of symmetry and spatial dimension has been established, while the application of their surface states remains a challenge. The gapless phases which have topologically stable Fermi surfaces could also exhibit peculiar surface states and topological transport phenomena in the bulk. In this thesis, the topological DIII-classs superconducting chains and the application of its Majorana edge states are studied. On the other hand, Weyl semimetals, as the representative example of topological gapless phases, and its exotic transport phenomena are also investigated. Majorana edge states have been a focus of condensed matter research for their potential applications in topological quantum computation, which appear in the topological DIII-class superconducting chains protected by both the particle-hole and time reversal symmetries. We utilize two charge-qubit arrays to explicitly simulate one type of DIII-class superconducting chains and the universal quantum operations performed on the Majorana edge states. It is shown that combined with one braiding operation, universal single-qubit operations on a Majorana-based qubit can be implemented by a controllable inductive coupling between two charge qubits at the ends of the arrays. It is further shown that in a similar way, a controlled-NOT gate for two topological qubits can be simulated in four charge-qubit arrays. Although the current scheme may not truly realize topological quantum operations, we elaborate that the operations in charge-qubit arrays are indeed robust against certain local perturbations. Weyl semimetals possess nontrivial Fermi surface topology in that the pair of Weyl points with opposite topological charges is separated from each other in momentum space. The physical manifestations of this Fermi surface topology are protected surface states and exotic transport phenomena including the anomalous Hall effect as well as the chiral magnetic effect. By studying the path integral measure under the chiral transformation, it is shown that these transport phenomena can be described by the chiral anomaly which appears when the chiral Weyl fermion couples to the topologically nontrivial gauge field. The case of the gauge anomaly for the Weyl fermion coupled to a non-Abelian gauge field is also discussed.
published_or_final_version
Physics
Doctoral
Doctor of Philosophy

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Sbierski, Björn [Verfasser]. „On disorder effects in topological insulators and semimetals / Björn Sbierski“. Berlin : Freie Universität Berlin, 2016. http://d-nb.info/1102197114/34.

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Lau, Alexander. „Symmetry-enriched topological states of matter in insulators and semimetals“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-233930.

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Topological states of matter are a novel family of phases that elude the conventional Landau paradigm of phase transitions. Topological phases are characterized by global topological invariants which are typically reflected in the quantization of physical observables. Moreover, their characteristic bulk-boundary correspondence often gives rise to robust surface modes with exceptional features, such as dissipationless charge transport or non-Abelian statistics. In this way, the study of topological states of matter not only broadens our knowledge of matter but could potentially lead to a whole new range of technologies and applications. In this light, it is of great interest to find novel topological phases and to study their unique properties. In this work, novel manifestations of topological states of matter are studied as they arise when materials are subject to additional symmetries. It is demonstrated how symmetries can profoundly enrich the topology of a system. More specifically, it is shown how symmetries lead to additional nontrivial states in systems which are already topological, drive trivial systems into a topological phase, lead to the quantization of formerly non-quantized observables, and give rise to novel manifestations of topological surface states. In doing so, this work concentrates on weakly interacting systems that can theoretically be described in a single-particle picture. In particular, insulating and semi-metallic topological phases in one, two, and three dimensions are investigated theoretically using single-particle techniques.

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Ekahana, Sandy Adhitia. „Investigation of topological nodal semimetals through angle-resolved photoemission spectroscopy“. Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:afed6156-7aa2-4ba9-afd1-af53d775494f.

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Nodal semimetals host either degenerate points (Dirac/Weyl points) or lines whose band topology in Brillouin zone can be classified either as trivial (normal nodal semimetals) or non trivial (topological nodal semimetals). This thesis investigates the electronic structure of two different categories of topological nodal semimetals probed by angleresolved photoemission spectroscopy (ARPES): The first material is Indium Bismuth (InBi). InBi is a semimetal with simple tetragonal structure with P4/nmm space group. This space group is predicted to host protected nodal lines along the perpendicular momentum direction at the high symmetry lines of the Brillouin zone boundary even under strong spin-orbit coupling (SOC) situation. As a semimetal with two heavy elements, InBi is a suitable candidate to test the prediction. The investigation by ARPES demonstrates not only that InBi hosts the nodal line in the presence of strong SOC, it also shows the signature of type-II Dirac crossing along the perpendicular momentum direction from the center of Brillouin zone. However, as the nodal line observed is trivial in nature, there is no exotic drumhead surface states observed in this material. This finding demonstrates that Dirac crossings can be protected in a non-symmorphic space group. The second material is NbIrTe₄ which is a semimetal that breaks inversion symmetry predicted to host only four Weyl points. This simplest configuration is confirmed by the measurement from the top and bottom surface of NbIrTe₄ showing only a pair of Fermi arcs each. Furthermore, it is found that the Fermi arc connectivity on the bottom surface experiences re-wiring as it evolves from Weyl points energy to the ARPES Fermi energy level. This change is attributed to the hybridisation between the surface and the bulk states as their projection lie within the vicinity of each other. The finding in this work demonstrates that although Fermi arcs are guaranteed in Weyl semimetals, their shape and connectivity are not protected and may be altered accordingly.

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Haubold, Erik [Verfasser], Bernd [Gutachter] Büchner und Oliver [Gutachter] Rader. „Electronic structure of topological semimetals / Erik Haubold ; Gutachter: Bernd Büchner, Oliver Rader“. Dresden : Technische Universität Dresden, 2019. http://d-nb.info/1226944779/34.

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Khalaf, Eslam [Verfasser], und Walter [Akademischer Betreuer] Metzner. „Mesoscopic phenomena in topological insulators, superconductors and semimetals / Eslam Khalaf ; Betreuer: Walter Metzner“. Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2017. http://d-nb.info/1137510145/34.

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Bücher zum Thema "Topological semimetals"

Pronin, Artem V. Linear Electrodynamic Response of Topological Semimetals. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-35637-7.

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Buchteile zum Thema "Topological semimetals"

Shen, Shun-Qing. „Topological Dirac and Weyl Semimetals“. In Springer Series in Solid-State Sciences, 207–29. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-4606-3_11.

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Zahid Hasan, M., Su-Yang Xu und Madhab Neupane. „Topological Insulators, Topological Dirac semimetals, Topological Crystalline Insulators, and Topological Kondo Insulators“. In Topological Insulators, 55–100. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527681594.ch4.

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Beidenkopf, Haim. „Momentum and Real-Space Study of Topological Semimetals and Topological Defects“. In Topological Matter, 245–56. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76388-0_10.

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Johnson, P. D. „Dirac cones and topological states: Dirac and Weyl semimetals“. In Physics of Solid Surfaces, 535–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-662-53908-8_128.

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Kim, Heejae. „Weyl Semimetals and Spinless $$Z_2$$ Magnetic Topological Crystalline Insulators with Glide Symmetry“. In Glide-Symmetric Z2 Magnetic Topological Crystalline Insulators, 51–64. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9077-8_3.

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Takahashi, Ryuji. „Weyl Semimetal in a Thin Topological Insulator“. In Springer Theses, 63–71. Tokyo: Springer Japan, 2015. http://dx.doi.org/10.1007/978-4-431-55534-6_4.

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Yokomizo, Kazuki. „Topological Semimetal Phase with Exceptional Points in One-dimensional Non-Hermitian Systems“. In Springer Theses, 57–71. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1858-2_5.

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Fujishiro, Yukako. „Topological Transport Properties of Magnetic Weyl Semimetal Co$$_3$$Sn$$_2$$S$$_2$$ Thin Flake“. In Exploration of Quantum Transport Phenomena via Engineering Emergent Magnetic Fields in Topological Magnets, 77–89. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-7293-4_5.

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„Topological semimetals“. In Topology in Condensed Matter, 121–37. WORLD SCIENTIFIC, 2021. http://dx.doi.org/10.1142/9789811237225_0005.

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„Topological Insulators and Semimetals“. In Modern Condensed Matter Physics, 362–75. Cambridge University Press, 2019. http://dx.doi.org/10.1017/9781316480649.015.

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Konferenzberichte zum Thema "Topological semimetals"

Rashidi, A., O. F. Shoron, Manik Goyal, David A. Kealhofer und S. Stemmer. „Topological Semimetals for Electronic Devices“. In 2021 IEEE International Electron Devices Meeting (IEDM). IEEE, 2021. http://dx.doi.org/10.1109/iedm19574.2021.9720503.

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Devyatov, Eduard. „JOSEPHSON CURRENT TRANSFER BY WEYL TOPOLOGICAL SEMIMETALS SURFACE STATES“. In International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1583.silicon-2020/145-149.

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Experiments on the study of topological surface states of magnetic and nonmagnetic Weyl semimetals charge transfer are presented. For surface states contribution the stationary and nonstationary Josephson effect realized at superconductortopological semi-metal-superconductor hybrid structures is applied.

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Hills, R. D. Y., M. Brada, Y. Liu, M. Pierpoint, M. B. Sobnack, W. M. Wu und F. V. Kusmartsev. „FROM GRAPHENE AND TOPOLOGICAL INSULATORS TO WEYL SEMIMETALS“. In 11th International School on Theoretical Physics. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814740371_0012.

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Wang, Lin, Xiaoshuang Chen und Wei Lu. „Topological Dirac Semimetals for Ultra-Sensitive Terahertz Detection“. In 2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz). IEEE, 2021. http://dx.doi.org/10.1109/irmmw-thz50926.2021.9567027.

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Shastri, Kunal, und Francesco Monticone. „Dissipation of Topological Charge in Plasmonic Weyl Semimetals“. In CLEO: Applications and Technology. Washington, D.C.: OSA, 2020. http://dx.doi.org/10.1364/cleo_at.2020.jw2d.21.

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Zhang, Xiao-Xiao. „Chiral modes of topological semimetals under magnetic field“. In Nano-Micro Conference 2017. London: Nature Research Society, 2017. http://dx.doi.org/10.11605/cp.nmc2017.01072.

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Vira, Alisha, Wei Pan und Zhigang Jiang. „Characterization of Topological Semimetals for Single Photon Detection.“ In Proposed for presentation at the Sandia Academic Alliance Spring 2021 Georgia Tech LDRD Virtual Poster Session held March 31, 2021. US DOE, 2021. http://dx.doi.org/10.2172/1855926.

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Shimano, Ryo, Yoshua Hirai und Naotaka Yoshikawa. „Floquet Engineering of 3-Dimensional Dirac Semimetals“. In Nonlinear Optics. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/nlo.2023.tu1b.1.

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We investigated the light-control of topological matter phases in 3-dimensional Dirac electron systems. Light-induced creation of chiral gauge field and also the realization of exotic Floquet-Weyl states are suggested from time-resolved terahertz Faraday rotation measurements.

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Patrashin, Mikhail, Norihiko Sekine, Kouichi Akahane, Akifumi Kasamatsu und Iwao Hosako. „Topological semimetals in InAs/GaInSb superlattices at room temperature“. In 2019 Compound Semiconductor Week (CSW). IEEE, 2019. http://dx.doi.org/10.1109/iciprm.2019.8819048.

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Samarth, N., W. Yanez und Y. Ou. „Spin-charge interconversion in topological insulators and topological semimetals for spin-orbit torque devices“. In 2021 IEEE International Electron Devices Meeting (IEDM). IEEE, 2021. http://dx.doi.org/10.1109/iedm19574.2021.9720699.

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Berichte der Organisationen zum Thema "Topological semimetals"

Drew, Howard. THz Plasmonics and Topological Optics of Weyl Semimetals. Office of Scientific and Technical Information (OSTI), März 2023. http://dx.doi.org/10.2172/1960780.

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