Direct observation of chiral edge current at zero magnetic field in odd-layer MnBi$_2$Te$_4$
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2023
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866910960110796800 |
|---|---|
| author | Zhu, Jinjiang Feng, Yang Zhou, Xiaodong Wang, Yongchao Lian, Zichen Lin, Weiyan He, Qiushi Lin, Yishi Wang, Youfang Yao, Hongxu Li, Hao Wu, Yang Wang, Jing Shen, Jian Zhang, Jinsong Wang, Yayu Wang, Yihua |
| author_facet | Zhu, Jinjiang Feng, Yang Zhou, Xiaodong Wang, Yongchao Lian, Zichen Lin, Weiyan He, Qiushi Lin, Yishi Wang, Youfang Yao, Hongxu Li, Hao Wu, Yang Wang, Jing Shen, Jian Zhang, Jinsong Wang, Yayu Wang, Yihua |
| contents | The chiral edge current is the boundary manifestation of the Chern number of a quantum anomalous Hall (QAH) insulator. Its direct observation is assumed to require well-quantized Hall conductance, and is so far lacking. The recently discovered van der Waals antiferromagnet MnBi$_2$Te$_4$ is theorized as 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-layer. The chirality of such edge current 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 | Preprint |
| id |
arxiv_https___arxiv_org_abs_2307_10150 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Direct observation of chiral edge current at zero magnetic field in odd-layer MnBi$_2$Te$_4$ Zhu, Jinjiang Feng, Yang Zhou, Xiaodong Wang, Yongchao Lian, Zichen Lin, Weiyan He, Qiushi Lin, Yishi Wang, Youfang Yao, Hongxu Li, Hao Wu, Yang Wang, Jing Shen, Jian Zhang, Jinsong Wang, Yayu Wang, Yihua Mesoscale and Nanoscale Physics The chiral edge current is the boundary manifestation of the Chern number of a quantum anomalous Hall (QAH) insulator. Its direct observation is assumed to require well-quantized Hall conductance, and is so far lacking. The recently discovered van der Waals antiferromagnet MnBi$_2$Te$_4$ is theorized as 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-layer. The chirality of such edge current 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. |
| title | Direct observation of chiral edge current at zero magnetic field in odd-layer MnBi$_2$Te$_4$ |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2307.10150 |