中国物理B ›› 2025, Vol. 34 ›› Issue (12): 126801-126801.doi: 10.1088/1674-1056/ae0926

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Unchanged top surface-state structures in three-dimensional topological insulator Sb2Te3 thin films in the presence of bottom-surface moiré potentials

Dezhi Song(宋德志)†, Fuyang Huang(黄扶旸)†, Jun Zhang(仉君)‡, and Ye-Ping Jiang(蒋烨平)§   

  1. Key Laboratory of Polar Materials and Devices, East China Normal University, Shanghai 200241, China
  • 收稿日期:2025-08-16 修回日期:2025-09-07 接受日期:2025-09-19 发布日期:2025-11-25
  • 通讯作者: Jun Zhang, Ye-Ping Jiang E-mail:zhangjun@ee.ecnu.edu.cn;ypjiang@clpm.ecnu.edu.cn
  • 基金资助:
    We acknowledge the supporting from the National Key R&D Program of China (Grant No. 2022YFA1403102) and the National Natural Science Foundation of China (Grant Nos. 12474478, 92065102, and 12574094).

Unchanged top surface-state structures in three-dimensional topological insulator Sb2Te3 thin films in the presence of bottom-surface moiré potentials

Dezhi Song(宋德志)†, Fuyang Huang(黄扶旸)†, Jun Zhang(仉君)‡, and Ye-Ping Jiang(蒋烨平)§   

  1. Key Laboratory of Polar Materials and Devices, East China Normal University, Shanghai 200241, China
  • Received:2025-08-16 Revised:2025-09-07 Accepted:2025-09-19 Published:2025-11-25
  • Contact: Jun Zhang, Ye-Ping Jiang E-mail:zhangjun@ee.ecnu.edu.cn;ypjiang@clpm.ecnu.edu.cn
  • About author:2025-126801-251421.pdf
  • Supported by:
    We acknowledge the supporting from the National Key R&D Program of China (Grant No. 2022YFA1403102) and the National Natural Science Foundation of China (Grant Nos. 12474478, 92065102, and 12574094).

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摘要： The exertion of a long-period potential on two-dimensional (2D) systems leads to band-structure downfolding and the formation of mini flat bands, thereby providing a route for band engineering and enabling the realization of new physical phenomena through the tuning of electron-electron interactions. In this work, the effect of the moiré superlattice formed between the substrate and the bottom quintuple layer (QL) of 3- and 4-QL three-dimensional (3D) topological insulator Sb$_{2}$Te$_{3}$ thin films on the top surface states is investigated. The scanning tunneling spectra reveal that the bulk-like bands exhibit potential variations consistent with the moiré pattern. In contrast, the surface states display only minimal potential variations, resulting in the absence of mini-band formation in the top surface states. These surface states remain nearly unaffected, as confirmed by Landau-level spectroscopy and simulations. The results suggest distinct roles of the bottom-surface moiré potential on the bulk states and the top surface states in the weak coupling regime between the two surfaces.

关键词: scanning tunneling spectroscopy, topological surface states, heterostructure, moiré potential

Abstract: The exertion of a long-period potential on two-dimensional (2D) systems leads to band-structure downfolding and the formation of mini flat bands, thereby providing a route for band engineering and enabling the realization of new physical phenomena through the tuning of electron-electron interactions. In this work, the effect of the moiré superlattice formed between the substrate and the bottom quintuple layer (QL) of 3- and 4-QL three-dimensional (3D) topological insulator Sb$_{2}$Te$_{3}$ thin films on the top surface states is investigated. The scanning tunneling spectra reveal that the bulk-like bands exhibit potential variations consistent with the moiré pattern. In contrast, the surface states display only minimal potential variations, resulting in the absence of mini-band formation in the top surface states. These surface states remain nearly unaffected, as confirmed by Landau-level spectroscopy and simulations. The results suggest distinct roles of the bottom-surface moiré potential on the bulk states and the top surface states in the weak coupling regime between the two surfaces.

Key words: scanning tunneling spectroscopy, topological surface states, heterostructure, moiré potential

中图分类号:  (Microscopy of surfaces, interfaces, and thin films)

  • 68.37.-d
68.37.Ef (Scanning tunneling microscopy (including chemistry induced with STM)) 73.20.At (Surface states, band structure, electron density of states) 73.21.Cd (Superlattices)