Quantized anomalous Hall resistivity achieved in molecular beam epitaxy-grown MnBi 2 Te 4 thin films

The intrinsic magnetic topological insulator MnBi Te provides a feasible pathway to the high-temperature quantum anomalous Hall (QAH) effect as well as various novel topological quantum phases. Although quantized transport properties have been observed in exfoliated MnBi Te thin flakes, it remains a...

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Bibliographic Details
Published in:National science review 2024-02, Vol.11 (2), p.nwad189
Main Authors: Bai, Yunhe, Li, Yuanzhao, Luan, Jianli, Liu, Ruixuan, Song, Wenyu, Chen, Yang, Ji, Peng-Fei, Zhang, Qinghua, Meng, Fanqi, Tong, Bingbing, Li, Lin, Jiang, Yuying, Gao, Zongwei, Gu, Lin, Zhang, Jinsong, Wang, Yayu, Xue, Qi-Kun, He, Ke, Feng, Yang, Feng, Xiao
Format: Article
Language:English
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Summary:The intrinsic magnetic topological insulator MnBi Te provides a feasible pathway to the high-temperature quantum anomalous Hall (QAH) effect as well as various novel topological quantum phases. Although quantized transport properties have been observed in exfoliated MnBi Te thin flakes, it remains a big challenge to achieve molecular beam epitaxy (MBE)-grown MnBi Te thin films even close to the quantized regime. In this work, we report the realization of quantized anomalous Hall resistivity in MBE-grown MnBi Te thin films with the chemical potential tuned by both controlled oxygen exposure and top gating. We find that elongated post-annealing obviously elevates the temperature to achieve quantization of the Hall resistivity, but also increases the residual longitudinal resistivity, indicating a picture of high-quality QAH puddles weakly coupled by tunnel barriers. These results help to clarify the puzzles in previous experimental studies on MnBi Te and to find a way out of the big difficulty in obtaining MnBi Te samples showing quantized transport properties.
ISSN:2053-714X