中国物理B ›› 2025, Vol. 34 ›› Issue (7): 76801-076801.doi: 10.1088/1674-1056/adcea3

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Characterization of antisite defects and in-gap states in antiferromagnetic MnSb2Te4

Junming Zhang(张峻铭)1,2, Ming Xi(席明)3,4, Yuchong Zhang(张羽翀)1,2, Hang Li(李航)1, Jiali Zhao(赵佳丽)1, Hechang Lei(雷和畅)3,4,†, Zhongxu Wei(魏忠旭)1,‡, and Tian Qian(钱天)1,§   

  1. 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100490, China;
    3 School of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing 100872, China;
    4 Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, China
  • 收稿日期:2025-04-03 修回日期:2025-04-17 接受日期:2025-04-21 出版日期:2025-06-18 发布日期:2025-06-18
  • 通讯作者: Hechang Lei, Zhongxu Wei, Tian Qian E-mail:hlei@ruc.edu.cn;zhongxuwei@iphy.ac.cn;tqian@iphy.ac.cn
  • 基金资助:
    Project supported by the National Key R&D Program of China (Grant Nos. 2022YFA1403800 and 2023YFA1406500) and the National Natural Science Foundation of China (Grant No. 12274459).

Characterization of antisite defects and in-gap states in antiferromagnetic MnSb2Te4

Junming Zhang(张峻铭)1,2, Ming Xi(席明)3,4, Yuchong Zhang(张羽翀)1,2, Hang Li(李航)1, Jiali Zhao(赵佳丽)1, Hechang Lei(雷和畅)3,4,†, Zhongxu Wei(魏忠旭)1,‡, and Tian Qian(钱天)1,§   

  1. 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100490, China;
    3 School of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing 100872, China;
    4 Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, China
  • Received:2025-04-03 Revised:2025-04-17 Accepted:2025-04-21 Online:2025-06-18 Published:2025-06-18
  • Contact: Hechang Lei, Zhongxu Wei, Tian Qian E-mail:hlei@ruc.edu.cn;zhongxuwei@iphy.ac.cn;tqian@iphy.ac.cn
  • Supported by:
    Project supported by the National Key R&D Program of China (Grant Nos. 2022YFA1403800 and 2023YFA1406500) and the National Natural Science Foundation of China (Grant No. 12274459).

摘要: Intrinsic magnetic topological insulators have been reported to exhibit novel physical phenomena such as the quantum anomalous Hall effect and axion insulator states, demonstrating potential for applications in spintronics and topological quantum computing. Here we perform low-temperature scanning tunneling microscopy (STM) investigations of the antiferromagnetic ground state of MnSb$_{2}$Te$_{4}$, a predicted magnetic topological insulator isostructural with MnBi$_{2}$Te$_{4}$. We visualize the hexagonal Te-terminated surface of MnSb$_{2}$Te$_{4}$ and identify two distinct defects originating from different antisite substitutions. Notably, we identify an in-gap state above the Fermi energy where the tunneling spectrum exhibits a negative differential conductance behavior. This electronic state can be modulated by external electric and magnetic fields, suggesting effective pathways for electronic state manipulation. Spin-resolved STM measurements further reveal additional magnetic resonance peaks associated with Mn antisite defects. Our results provide novel insights into the investigation of magnetic topological insulators and demonstrate a promising approach to modulate the localized electronic states.

关键词: magnetic topological insulator, antisite defects, tunable electronic states, scanning tunneling microscopy

Abstract: Intrinsic magnetic topological insulators have been reported to exhibit novel physical phenomena such as the quantum anomalous Hall effect and axion insulator states, demonstrating potential for applications in spintronics and topological quantum computing. Here we perform low-temperature scanning tunneling microscopy (STM) investigations of the antiferromagnetic ground state of MnSb$_{2}$Te$_{4}$, a predicted magnetic topological insulator isostructural with MnBi$_{2}$Te$_{4}$. We visualize the hexagonal Te-terminated surface of MnSb$_{2}$Te$_{4}$ and identify two distinct defects originating from different antisite substitutions. Notably, we identify an in-gap state above the Fermi energy where the tunneling spectrum exhibits a negative differential conductance behavior. This electronic state can be modulated by external electric and magnetic fields, suggesting effective pathways for electronic state manipulation. Spin-resolved STM measurements further reveal additional magnetic resonance peaks associated with Mn antisite defects. Our results provide novel insights into the investigation of magnetic topological insulators and demonstrate a promising approach to modulate the localized electronic states.

Key words: magnetic topological insulator, antisite defects, tunable electronic states, scanning tunneling microscopy

中图分类号:  (Scanning tunneling microscopy (including chemistry induced with STM))

  • 68.37.Ef
75.50.Ee (Antiferromagnetics) 73.21.Ac (Multilayers) 07.79.Cz (Scanning tunneling microscopes)