中国物理B ›› 2026, Vol. 35 ›› Issue (8): 86802-086802.doi: 10.1088/1674-1056/ae66dd

• • 上一篇    

Layer-dependent local gate response in graphene-supported TaSe2 films studied by gate-tunable STM

Kefan Wu(吴可凡)1,2,†, Linfei Li(李林飞)2,3,†,‡, Zhixuan Li(李志轩)1,2,†, Ke Zhu(祝轲)2,1, Jiayi Wang(王嘉翌)2,1, Hui Guo(郭辉)2,1, Shiyu Zhu(朱诗雨)2,1, Xiao Lin(林晓)1,2,§, and Hong-Jun Gao(高鸿钧)2,1   

  1. 1 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China;
    2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    3 School of Materials Science and Engineering, School of Interdisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
  • 收稿日期:2026-04-03 修回日期:2026-04-23 接受日期:2026-04-30 发布日期:2026-07-23
  • 通讯作者: Linfei Li, Xiao Lin E-mail:lilinfei@bit.edu.cn;xlin@ucas.ac.cn
  • 基金资助:
    The work is supported by the National Natural Science Foundation of China (Grant Nos. 12522408, 62488201, 61925111, U23A6015, 52572188, 12374199, and 52250402), the National Key Research and Development Program of China (Grant Nos. 2024YFA1207800 and 2025YFA1212800), CAS Project for Young Scientists in Basic Research (Grant No. YSBR-003), and the Beijing Nova Program (20240484651). This work also benefitted from the resources and support from the Electron Microscopy Center at the University of Chinese Academy of Sciences.

Layer-dependent local gate response in graphene-supported TaSe2 films studied by gate-tunable STM

Kefan Wu(吴可凡)1,2,†, Linfei Li(李林飞)2,3,†,‡, Zhixuan Li(李志轩)1,2,†, Ke Zhu(祝轲)2,1, Jiayi Wang(王嘉翌)2,1, Hui Guo(郭辉)2,1, Shiyu Zhu(朱诗雨)2,1, Xiao Lin(林晓)1,2,§, and Hong-Jun Gao(高鸿钧)2,1   

  1. 1 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China;
    2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    3 School of Materials Science and Engineering, School of Interdisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
  • Received:2026-04-03 Revised:2026-04-23 Accepted:2026-04-30 Published:2026-07-23
  • Contact: Linfei Li, Xiao Lin E-mail:lilinfei@bit.edu.cn;xlin@ucas.ac.cn
  • Supported by:
    The work is supported by the National Natural Science Foundation of China (Grant Nos. 12522408, 62488201, 61925111, U23A6015, 52572188, 12374199, and 52250402), the National Key Research and Development Program of China (Grant Nos. 2024YFA1207800 and 2025YFA1212800), CAS Project for Young Scientists in Basic Research (Grant No. YSBR-003), and the Beijing Nova Program (20240484651). This work also benefitted from the resources and support from the Electron Microscopy Center at the University of Chinese Academy of Sciences.

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摘要： Gate-tunable scanning tunnelling microscopy (STM) enables direct correlation between electrostatic gating and local electronic states in two-dimensional correlated materials. Here, we investigate TaSe$_2$ films on graphene using a home-built gate-tunable STM setup. Large-area and atomically resolved STM images reveal well-defined TaSe$_2$ islands and an ordered charge-density-wave (CDW) superstructure. Monolayer TaSe$_2$ shows spatially resolved scanning tunnelling spectroscopy (STS) features but a strongly suppressed gate response under back-gate voltages. In contrast, bilayer TaSe$_2$ exhibits a richer zero-gate electronic structure and systematic bias-dependent evolution of CDW contrast. Fixed-point gate-dependent STS in the bilayer region demonstrates clear spectral-weight redistribution and low-energy feature evolution. Our results establish a feasible gate-tunable STM protocol for TaSe$_2$/graphene heterostructures and reveal pronounced layer-dependent local gate response in correlated two-dimensional systems.

关键词: gate-tunable STM, TaSe$_2$, charge-density wave, gate response

Abstract: Gate-tunable scanning tunnelling microscopy (STM) enables direct correlation between electrostatic gating and local electronic states in two-dimensional correlated materials. Here, we investigate TaSe$_2$ films on graphene using a home-built gate-tunable STM setup. Large-area and atomically resolved STM images reveal well-defined TaSe$_2$ islands and an ordered charge-density-wave (CDW) superstructure. Monolayer TaSe$_2$ shows spatially resolved scanning tunnelling spectroscopy (STS) features but a strongly suppressed gate response under back-gate voltages. In contrast, bilayer TaSe$_2$ exhibits a richer zero-gate electronic structure and systematic bias-dependent evolution of CDW contrast. Fixed-point gate-dependent STS in the bilayer region demonstrates clear spectral-weight redistribution and low-energy feature evolution. Our results establish a feasible gate-tunable STM protocol for TaSe$_2$/graphene heterostructures and reveal pronounced layer-dependent local gate response in correlated two-dimensional systems.

Key words: gate-tunable STM, TaSe$_2$, charge-density wave, gate response

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

  • 68.37.Ef
71.45.Lr (Charge-density-wave systems) 73.20.At (Surface states, band structure, electron density of states) 73.40.Qv (Metal-insulator-semiconductor structures (including semiconductor-to-insulator))