中国物理B ›› 2024, Vol. 33 ›› Issue (6): 67402-067402.doi: 10.1088/1674-1056/ad362e

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Surface doping manipulation of the insulating ground states in Ta2Pd3Te5 and Ta2Ni3Te5

Bei Jiang(江北)1,2,†, Jingyu Yao(姚静宇)1,2,†, Dayu Yan(闫大禹)1,2,†, Zhaopeng Guo(郭照芃)1, Gexing Qu(屈歌星)1,2, Xiutong Deng(邓修同)1,2, Yaobo Huang(黄耀波)4, Hong Ding(丁洪)5,6, Youguo Shi(石友国)1,2,3, Zhijun Wang(王志俊)1,2, and Tian Qian(钱天)1,‡   

  1. 1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China;
    5 Tsung-Dao Lee Institute, New Cornerstone Science Laboratory, and School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 201210, China;
    6 Hefei National Laboratory, Hefei 230088, China
  • 收稿日期:2024-02-20 修回日期:2024-03-12 接受日期:2024-03-21 出版日期:2024-06-18 发布日期:2024-06-18
  • 通讯作者: Tian Qian E-mail:tqian@iphy.ac.cn
  • 基金资助:
    Project supported by the Ministry of Science and Technology of China (Grant No. 2022YFA1403800), the National Natural Science Foundation of China (Grant Nos. U2032204, 12188101, and U22A6005), the Chinese Academy of Sciences (Grant No. XDB33000000), the Synergetic Extreme Condition User Facility (SECUF), and the Center for Materials Genome.

Surface doping manipulation of the insulating ground states in Ta2Pd3Te5 and Ta2Ni3Te5

Bei Jiang(江北)1,2,†, Jingyu Yao(姚静宇)1,2,†, Dayu Yan(闫大禹)1,2,†, Zhaopeng Guo(郭照芃)1, Gexing Qu(屈歌星)1,2, Xiutong Deng(邓修同)1,2, Yaobo Huang(黄耀波)4, Hong Ding(丁洪)5,6, Youguo Shi(石友国)1,2,3, Zhijun Wang(王志俊)1,2, and Tian Qian(钱天)1,‡   

  1. 1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China;
    5 Tsung-Dao Lee Institute, New Cornerstone Science Laboratory, and School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 201210, China;
    6 Hefei National Laboratory, Hefei 230088, China
  • Received:2024-02-20 Revised:2024-03-12 Accepted:2024-03-21 Online:2024-06-18 Published:2024-06-18
  • Contact: Tian Qian E-mail:tqian@iphy.ac.cn
  • Supported by:
    Project supported by the Ministry of Science and Technology of China (Grant No. 2022YFA1403800), the National Natural Science Foundation of China (Grant Nos. U2032204, 12188101, and U22A6005), the Chinese Academy of Sciences (Grant No. XDB33000000), the Synergetic Extreme Condition User Facility (SECUF), and the Center for Materials Genome.

摘要: Manipulating emergent quantum phenomena is a key issue for understanding the underlying physics and contributing to possible applications. Here we study the evolution of insulating ground states of Ta$_{2}$Pd$_{3}$Te$_{5}$ and Ta$_{2}$Ni$_{3}$Te$_{5}$ under in-situ surface potassium deposition via angle-resolved photoemission spectroscopy. Our results confirm the excitonic insulator character of Ta$_{2}$Pd$_{3}$Te$_{5}$. Upon surface doping, the size of its global gap decreases obviously. After a deposition time of more than 7 min, the potassium atoms induce a metal-insulator phase transition and make the system recover to a normal state. In contrast, our results show that the isostructural compound Ta$_{2}$Ni$_{3}$Te$_{5}$ is a conventional insulator. The size of its global gap decreases upon surface doping, but persists positive throughout the doping process. Our results not only confirm the excitonic origin of the band gap in Ta$_{2}$Pd$_{3}$Te$_{5}$, but also offer an effective method for designing functional quantum devices in the future.

关键词: excitonic insulator, metal-insulator phase transition, surface doping, angle-resolved photoemission spectroscopy

Abstract: Manipulating emergent quantum phenomena is a key issue for understanding the underlying physics and contributing to possible applications. Here we study the evolution of insulating ground states of Ta$_{2}$Pd$_{3}$Te$_{5}$ and Ta$_{2}$Ni$_{3}$Te$_{5}$ under in-situ surface potassium deposition via angle-resolved photoemission spectroscopy. Our results confirm the excitonic insulator character of Ta$_{2}$Pd$_{3}$Te$_{5}$. Upon surface doping, the size of its global gap decreases obviously. After a deposition time of more than 7 min, the potassium atoms induce a metal-insulator phase transition and make the system recover to a normal state. In contrast, our results show that the isostructural compound Ta$_{2}$Ni$_{3}$Te$_{5}$ is a conventional insulator. The size of its global gap decreases upon surface doping, but persists positive throughout the doping process. Our results not only confirm the excitonic origin of the band gap in Ta$_{2}$Pd$_{3}$Te$_{5}$, but also offer an effective method for designing functional quantum devices in the future.

Key words: excitonic insulator, metal-insulator phase transition, surface doping, angle-resolved photoemission spectroscopy

中图分类号:  (Electronic structure (photoemission, etc.))

  • 74.25.Jb
79.60.-i (Photoemission and photoelectron spectra) 71.35.-y (Excitons and related phenomena) 71.30.+h (Metal-insulator transitions and other electronic transitions)