Weyl, Dirac and high-fold chiral fermions in topological quantum matter
Quantum materials hosting Weyl fermions have opened a new era of research in condensed matter physics. First proposed in 1929 in the context of particle physics, Weyl fermions have yet to be observed as elementary particles. In 2015, Weyl fermions were detected as collective electronic excitations i...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Language: | English |
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2021
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| Online Access: | https://hdl.handle.net/10356/148526 |
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| author | Hasan, M. Zahid Chang, Guoqing Belopolski, Ilya Bian, Guang Xu, Su-Yang Yin, Jia-Xin |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Hasan, M. Zahid Chang, Guoqing Belopolski, Ilya Bian, Guang Xu, Su-Yang Yin, Jia-Xin |
| author_sort | Hasan, M. Zahid |
| collection | NTU |
| description | Quantum materials hosting Weyl fermions have opened a new era of research in condensed matter physics. First proposed in 1929 in the context of particle physics, Weyl fermions have yet to be observed as elementary particles. In 2015, Weyl fermions were detected as collective electronic excitations in the strong spin–orbit coupled material tantalum arsenide, TaAs. This discovery was followed by a flurry of experimental and theoretical explorations of Weyl phenomena in materials. Weyl materials naturally lend themselves to the exploration of the topological index associated with Weyl fermions and their divergent Berry curvature field, as well as the topological bulk–boundary correspondence, giving rise to protected conducting surface states. Here, we review the broader class of Weyl topological phenomena in materials, starting with the observation of emergent Weyl fermions in the bulk and Fermi arc states on the surface of the TaAs family of crystals by photoemission spectroscopy. We then discuss several exotic optical and magnetic responses observed in these materials, as well as progress in developing related chiral materials. We discuss the conceptual development of high-fold chiral fermions, which generalize Weyl fermions, and we review the observation of high-fold chiral fermion phases by taking the rhodium silicide, RhSi, family of crystals as a prime example. Lastly, we discuss recent advances in Weyl line phases in magnetic topological materials. With this Review, we aim to provide an introduction to the basic concepts underlying Weyl physics in condensed matter, and to representative materials and their electronic structures and topology as revealed by spectroscopic studies. We hope this work serves as a guide for future theoretical and experimental explorations of chiral fermions and related topological quantum systems with potentially enhanced functionalities. |
| first_indexed | 2024-10-01T05:24:08Z |
| format | Journal Article |
| id | ntu-10356/148526 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:24:08Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1485262023-02-28T19:54:02Z Weyl, Dirac and high-fold chiral fermions in topological quantum matter Hasan, M. Zahid Chang, Guoqing Belopolski, Ilya Bian, Guang Xu, Su-Yang Yin, Jia-Xin School of Physical and Mathematical Sciences Science::Physics Topological Insulators Condensed-matter Physics Quantum materials hosting Weyl fermions have opened a new era of research in condensed matter physics. First proposed in 1929 in the context of particle physics, Weyl fermions have yet to be observed as elementary particles. In 2015, Weyl fermions were detected as collective electronic excitations in the strong spin–orbit coupled material tantalum arsenide, TaAs. This discovery was followed by a flurry of experimental and theoretical explorations of Weyl phenomena in materials. Weyl materials naturally lend themselves to the exploration of the topological index associated with Weyl fermions and their divergent Berry curvature field, as well as the topological bulk–boundary correspondence, giving rise to protected conducting surface states. Here, we review the broader class of Weyl topological phenomena in materials, starting with the observation of emergent Weyl fermions in the bulk and Fermi arc states on the surface of the TaAs family of crystals by photoemission spectroscopy. We then discuss several exotic optical and magnetic responses observed in these materials, as well as progress in developing related chiral materials. We discuss the conceptual development of high-fold chiral fermions, which generalize Weyl fermions, and we review the observation of high-fold chiral fermion phases by taking the rhodium silicide, RhSi, family of crystals as a prime example. Lastly, we discuss recent advances in Weyl line phases in magnetic topological materials. With this Review, we aim to provide an introduction to the basic concepts underlying Weyl physics in condensed matter, and to representative materials and their electronic structures and topology as revealed by spectroscopic studies. We hope this work serves as a guide for future theoretical and experimental explorations of chiral fermions and related topological quantum systems with potentially enhanced functionalities. National Research Foundation (NRF) Accepted version G.C. would like to acknowledge the support of the National Research Foundation, Singapore under its NRF Fellowship Award (NRF-NRFF13-2021-0010) and the Nanyang Assistant Professorship grant from Nanyang Technological University. S.Y.X. was supported by the Center for the Advancement of Topological Semimetals, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE) Office of Science, through the Ames Laboratory under contract DE-AC0207CH11358. S.Y.X. acknowledges the Corning Fund for Faculty Development. G.B. was supported by the US National Science Foundation under Grant No. NSF DMR-1809160. 2021-04-28T08:16:17Z 2021-04-28T08:16:17Z 2021 Journal Article Hasan, M. Z., Chang, G., Belopolski, I., Bian, G., Xu, S. & Yin, J. (2021). Weyl, Dirac and high-fold chiral fermions in topological quantum matter. Nature Reviews Materials. https://dx.doi.org/10.1038/s41578-021-00301-3 2058-8437 https://hdl.handle.net/10356/148526 10.1038/s41578-021-00301-3 en Nature Reviews Materials © 2021 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. This paper was published in Nature Reviews Materials and is made available with permission of Macmillan Publishers Limited, part of Springer Nature application/pdf |
| spellingShingle | Science::Physics Topological Insulators Condensed-matter Physics Hasan, M. Zahid Chang, Guoqing Belopolski, Ilya Bian, Guang Xu, Su-Yang Yin, Jia-Xin Weyl, Dirac and high-fold chiral fermions in topological quantum matter |
| title | Weyl, Dirac and high-fold chiral fermions in topological quantum matter |
| title_full | Weyl, Dirac and high-fold chiral fermions in topological quantum matter |
| title_fullStr | Weyl, Dirac and high-fold chiral fermions in topological quantum matter |
| title_full_unstemmed | Weyl, Dirac and high-fold chiral fermions in topological quantum matter |
| title_short | Weyl, Dirac and high-fold chiral fermions in topological quantum matter |
| title_sort | weyl dirac and high fold chiral fermions in topological quantum matter |
| topic | Science::Physics Topological Insulators Condensed-matter Physics |
| url | https://hdl.handle.net/10356/148526 |
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