Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator
Abstract The chiral edge current is the boundary manifestation of the Chern number of a quantum anomalous Hall (QAH) insulator. The van der Waals antiferromagnet MnBi2Te4 is theorized to be a QAH in odd-layers but has shown Hall resistivity below the quantization value at zero magnetic field. Here,...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-01-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-025-56326-7 |
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| author | Jinjiang Zhu Yang Feng Xiaodong Zhou Yongchao Wang Hongxu Yao Zichen Lian Weiyan Lin Qiushi He Yishi Lin Youfang Wang Yongqian Wang Shuai Yang Hao Li Yang Wu Chang Liu Jing Wang Jian Shen Jinsong Zhang Yayu Wang Yihua Wang |
| author_facet | Jinjiang Zhu Yang Feng Xiaodong Zhou Yongchao Wang Hongxu Yao Zichen Lian Weiyan Lin Qiushi He Yishi Lin Youfang Wang Yongqian Wang Shuai Yang Hao Li Yang Wu Chang Liu Jing Wang Jian Shen Jinsong Zhang Yayu Wang Yihua Wang |
| author_sort | Jinjiang Zhu |
| collection | DOAJ |
| description | Abstract The chiral edge current is the boundary manifestation of the Chern number of a quantum anomalous Hall (QAH) insulator. The van der Waals antiferromagnet MnBi2Te4 is theorized to be a QAH in odd-layers but has shown Hall resistivity below the quantization value at zero magnetic field. Here, we perform scanning superconducting quantum interference device (sSQUID) microscopy on these seemingly failed QAH insulators to image their current distribution. When gated to the charge neutral point, our device exhibits edge current, which flows unidirectionally on the odd-layer boundary both with vacuum and with the even-layers. The edge current chirality reverses with the magnetization of the bulk. Surprisingly, we find the edge channels coexist with finite bulk conduction even though the bulk chemical potential is in the band gap, suggesting their robustness under significant edge–bulk scattering. Our result establishes the existence of chiral edge currents in a topological antiferromagnet and offers an alternative for identifying QAH states. |
| format | Article |
| id | doaj-art-dca78e7c0b714dfe932aa2517104f5d1 |
| institution | Kabale University |
| issn | 2041-1723 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-dca78e7c0b714dfe932aa2517104f5d12025-01-26T12:42:29ZengNature PortfolioNature Communications2041-17232025-01-011611910.1038/s41467-025-56326-7Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulatorJinjiang Zhu0Yang Feng1Xiaodong Zhou2Yongchao Wang3Hongxu Yao4Zichen Lian5Weiyan Lin6Qiushi He7Yishi Lin8Youfang Wang9Yongqian Wang10Shuai Yang11Hao Li12Yang Wu13Chang Liu14Jing Wang15Jian Shen16Jinsong Zhang17Yayu Wang18Yihua Wang19State Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityBeijing Academy of Quantum Information SciencesInstitute for Nanoelectronic Devices and Quantum Computing, Fudan UniversityBeijing Innovation Center for Future Chips, Tsinghua UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityState Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityBeijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of ChinaBeijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of ChinaSchool of Materials Science and Engineering, Tsinghua UniversityTsinghua-Foxconn Nanotechnology Research Center, Department of Physics, Tsinghua UniversityBeijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of ChinaState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityState Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua UniversityState Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua UniversityState Key Laboratory of Surface Physics and Department of Physics, Fudan UniversityAbstract The chiral edge current is the boundary manifestation of the Chern number of a quantum anomalous Hall (QAH) insulator. The van der Waals antiferromagnet MnBi2Te4 is theorized to be a QAH in odd-layers but has shown Hall resistivity below the quantization value at zero magnetic field. Here, we perform scanning superconducting quantum interference device (sSQUID) microscopy on these seemingly failed QAH insulators to image their current distribution. When gated to the charge neutral point, our device exhibits edge current, which flows unidirectionally on the odd-layer boundary both with vacuum and with the even-layers. The edge current chirality reverses with the magnetization of the bulk. Surprisingly, we find the edge channels coexist with finite bulk conduction even though the bulk chemical potential is in the band gap, suggesting their robustness under significant edge–bulk scattering. Our result establishes the existence of chiral edge currents in a topological antiferromagnet and offers an alternative for identifying QAH states.https://doi.org/10.1038/s41467-025-56326-7 |
| spellingShingle | Jinjiang Zhu Yang Feng Xiaodong Zhou Yongchao Wang Hongxu Yao Zichen Lian Weiyan Lin Qiushi He Yishi Lin Youfang Wang Yongqian Wang Shuai Yang Hao Li Yang Wu Chang Liu Jing Wang Jian Shen Jinsong Zhang Yayu Wang Yihua Wang Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator Nature Communications |
| title | Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator |
| title_full | Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator |
| title_fullStr | Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator |
| title_full_unstemmed | Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator |
| title_short | Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator |
| title_sort | direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator |
| url | https://doi.org/10.1038/s41467-025-56326-7 |
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