中国物理B ›› 2023, Vol. 32 ›› Issue (4): 47502-047502.doi: 10.1088/1674-1056/acb423

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Doping-enhanced robustness of anomaly-related magnetoresistance in WTe2±α flakes

Jianchao Meng(孟建超)1,2, Xinxiang Chen(陈鑫祥)1, Tingna Shao(邵婷娜)1, Mingrui Liu(刘明睿)3, Weimin Jiang(姜伟民)1, Zitao Zhang(张子涛)1, Changmin Xiong(熊昌民)1, Ruifen Dou(窦瑞芬)1,†, and Jiacai Nie(聂家财)1,‡   

  1. 1 Department of Physics, Beijing Normal University, Beijing 100875, China;
    2 College of Science, Inner Mongolia University of Technology, Hohhot 010051, China;
    3 State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
  • 收稿日期:2022-09-17 修回日期:2022-12-12 接受日期:2023-01-18 出版日期:2023-03-10 发布日期:2023-03-30
  • 通讯作者: Ruifen Dou, Jiacai Nie E-mail:rfdou@bnu.edu.cn;jcnie@bnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 92065110, 11674031, 11974048, and 12074334) and the National Basic Research Program of China (Grant Nos. 2014CB920903 and 2013CB921701).

Doping-enhanced robustness of anomaly-related magnetoresistance in WTe2±α flakes

Jianchao Meng(孟建超)1,2, Xinxiang Chen(陈鑫祥)1, Tingna Shao(邵婷娜)1, Mingrui Liu(刘明睿)3, Weimin Jiang(姜伟民)1, Zitao Zhang(张子涛)1, Changmin Xiong(熊昌民)1, Ruifen Dou(窦瑞芬)1,†, and Jiacai Nie(聂家财)1,‡   

  1. 1 Department of Physics, Beijing Normal University, Beijing 100875, China;
    2 College of Science, Inner Mongolia University of Technology, Hohhot 010051, China;
    3 State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
  • Received:2022-09-17 Revised:2022-12-12 Accepted:2023-01-18 Online:2023-03-10 Published:2023-03-30
  • Contact: Ruifen Dou, Jiacai Nie E-mail:rfdou@bnu.edu.cn;jcnie@bnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 92065110, 11674031, 11974048, and 12074334) and the National Basic Research Program of China (Grant Nos. 2014CB920903 and 2013CB921701).

摘要: We study systematically the negative magnetoresistance ($MR$) effect in WTe$_{2\pm \alpha }$ flakes with different thicknesses and doping concentrations. The negative $MR$ is sensitive to the relative orientation between electrical-/magnetic-field and crystallographic orientation of WTe$_{2\pm \alpha }$. The analysis proves that the negative $MR$ originates from chiral anomaly and is anisotropic. Maximum entropy mobility spectrum is used to analyze the electron and hole concentrations in the flake samples. It is found that the negative $MR$ observed in WTe$_{2\pm \alpha }$ flakes with low doping concentration is small, and the high doping concentration is large. The doping-induced disorder obviously inhibits the positive $MR$, so the negative $MR$ can be more easily observed. In a word, we introduce disorder to suppress positive $MR$ by doping, and successfully obtain the negative $MR$ in WTe$_{2\pm \alpha }$ flakes with different thicknesses and doping concentrations, which indicates that the chiral anomaly effect in WTe$_{2}$ is robust.

关键词: Weyl semimetal, WTe2±α flakes, doping, chiral anomaly, robustness

Abstract: We study systematically the negative magnetoresistance ($MR$) effect in WTe$_{2\pm \alpha }$ flakes with different thicknesses and doping concentrations. The negative $MR$ is sensitive to the relative orientation between electrical-/magnetic-field and crystallographic orientation of WTe$_{2\pm \alpha }$. The analysis proves that the negative $MR$ originates from chiral anomaly and is anisotropic. Maximum entropy mobility spectrum is used to analyze the electron and hole concentrations in the flake samples. It is found that the negative $MR$ observed in WTe$_{2\pm \alpha }$ flakes with low doping concentration is small, and the high doping concentration is large. The doping-induced disorder obviously inhibits the positive $MR$, so the negative $MR$ can be more easily observed. In a word, we introduce disorder to suppress positive $MR$ by doping, and successfully obtain the negative $MR$ in WTe$_{2\pm \alpha }$ flakes with different thicknesses and doping concentrations, which indicates that the chiral anomaly effect in WTe$_{2}$ is robust.

Key words: Weyl semimetal, WTe2±α flakes, doping, chiral anomaly, robustness

中图分类号:  (Magnetotransport phenomena; materials for magnetotransport)

  • 75.47.-m
61.46.-w (Structure of nanoscale materials) 61.72.-y (Defects and impurities in crystals; microstructure)