Chiral Landau levels in Weyl semimetal NbAs with multiple topological carriers
| Autor: | Zhilin Li, Zhengcai Xia, Cheng Zhang, Faxian Xiu, Xiang Yuan, Weiyi Wang, Zhongbo Yan, Dmitry Smirnov, Zefang Ye, F. Chen, Zehao Lin, Mengyao Zhang, Hugen Yan, Xiaoxing Zhang, Zhong Wang, Minhao Zhao, Cui Shang, Tian Xie, Xiaolong Chen, Yuxuan Jiang, Yanwen Liu, Jiaxiang Wang, Jonathan Ludwig, Chaoyu Song |
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| Rok vydání: | 2018 |
| Předmět: |
Science
media_common.quotation_subject General Physics and Astronomy Weyl semimetal FOS: Physical sciences 02 engineering and technology Electron Topology 01 natural sciences Asymmetry Article General Biochemistry Genetics and Molecular Biology Condensed Matter::Materials Science symbols.namesake 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) lcsh:Science Mathematics::Representation Theory 010306 general physics media_common Physics Chiral anomaly Condensed Matter - Materials Science Multidisciplinary Condensed Matter - Mesoscale and Nanoscale Physics Materials Science (cond-mat.mtrl-sci) General Chemistry Fermion Landau quantization Mathematics::Spectral Theory 021001 nanoscience & nanotechnology Zeroth law of thermodynamics Dirac fermion symbols lcsh:Q Condensed Matter::Strongly Correlated Electrons 0210 nano-technology Physics - Optics Optics (physics.optics) |
| Zdroj: | Nature Communications Nature Communications, Vol 9, Iss 1, Pp 1-9 (2018) |
| DOI: | 10.48550/arxiv.1805.04206 |
| Popis: | Recently, Weyl semimetals have been experimentally discovered in both inversion-symmetry-breaking and time-reversal-symmetry-breaking crystals. The non-trivial topology in Weyl semimetals can manifest itself with exotic phenomena, which have been extensively investigated by photoemission and transport measurements. Despite the numerous experimental efforts on Fermi arcs and chiral anomaly, the existence of unconventional zeroth Landau levels, as a unique hallmark of Weyl fermions, which is highly related to chiral anomaly, remains elusive owing to the stringent experimental requirements. Here, we report the magneto-optical study of Landau quantization in Weyl semimetal NbAs. High magnetic fields drive the system toward the quantum limit, which leads to the observation of zeroth chiral Landau levels in two inequivalent Weyl nodes. As compared to other Landau levels, the zeroth chiral Landau level exhibits a distinct linear dispersion in magnetic field direction and allows the optical transitions without the limitation of zero z momentum or \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt B$$\end{document}B magnetic field evolution. The magnetic field dependence of the zeroth Landau levels further verifies the predicted particle-hole asymmetry of the Weyl cones. Meanwhile, the optical transitions from the normal Landau levels exhibit the coexistence of multiple carriers including an unexpected massive Dirac fermion, pointing to a more complex topological nature in inversion-symmetry-breaking Weyl semimetals. Our results provide insights into the Landau quantization of Weyl fermions and demonstrate an effective tool for studying complex topological systems. How the carriers behave in a Weyl semimetal if they occupy the lowest Landau level remains elusive. Here, the authors report evidences of electrons occupying zeroth chiral Landau levels with distinct linear dispersion behaviors for two inequivalent Weyl nodes in a Weyl semimetal NbAs. |
| Databáze: | OpenAIRE |
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