中国物理B ›› 2023, Vol. 32 ›› Issue (10): 107404-107404.doi: 10.1088/1674-1056/acec40

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Rubidium-induced phase transitions among metallic, band-insulating, Mott-insulating phases in 1T-TaS2

Zhengguo Wang(王政国), Weiliang Yao(姚伟良), Yudi Wang(王宇迪), Ziming Xin(信子鸣), Tingting Han(韩婷婷), Lei Chen(陈磊), Yi Ou(欧仪), Yu Zhu(朱玉), Cong Cai(蔡淙), Yuan Li(李源), and Yan Zhang(张焱)   

  1. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2023-05-10 修回日期:2023-07-19 接受日期:2023-08-01 出版日期:2023-09-21 发布日期:2023-09-27
  • 通讯作者: Yan Zhang E-mail:yzhang85@pku.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11888101, 91421107, and 11574004) and the National Key Research and Development Program of China (Grant Nos. 2018YFA0305602 and 2016YFA0301003).

Rubidium-induced phase transitions among metallic, band-insulating, Mott-insulating phases in 1T-TaS2

Zhengguo Wang(王政国), Weiliang Yao(姚伟良), Yudi Wang(王宇迪), Ziming Xin(信子鸣), Tingting Han(韩婷婷), Lei Chen(陈磊), Yi Ou(欧仪), Yu Zhu(朱玉), Cong Cai(蔡淙), Yuan Li(李源), and Yan Zhang(张焱)   

  1. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
  • Received:2023-05-10 Revised:2023-07-19 Accepted:2023-08-01 Online:2023-09-21 Published:2023-09-27
  • Contact: Yan Zhang E-mail:yzhang85@pku.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11888101, 91421107, and 11574004) and the National Key Research and Development Program of China (Grant Nos. 2018YFA0305602 and 2016YFA0301003).

摘要: Realizing phase transitions via non-thermal sample manipulations is important not only for applications, but also for uncovering the underlying physics. Here, we report on the discovery of two distinct metal-insulator transitions in 1T-TaS2 via angle-resolved photoemission spectroscopy and in-situ rubidium deposition. At 205 K, the rubidium deposition drives a normal metal-insulator transition via filling electrons into the conduction band. While at 225 K, however, the rubidium deposition drives a bandwidth-controlled Mott transition as characterized by a rapid collapsing of Mott gap and a loss of spectral weight of the lower Hubbard band. Our result, from a doping-controlled perspective, succeeds in distinguishing the metallic, band-insulating, and Mott-insulating phases of 1T-TaS2, manifesting a delicate balance among the electron-itineracy, interlayer-coupling and Coulomb repulsion. We also establish an effective method to tune the balance between these interactions, which is useful in seeking exotic electronic phases and designing functional phase-changing devices.

关键词: angle-resolved photoemission spectroscopy, metal-insulator transition, transition metal dichalcogenides

Abstract: Realizing phase transitions via non-thermal sample manipulations is important not only for applications, but also for uncovering the underlying physics. Here, we report on the discovery of two distinct metal-insulator transitions in 1T-TaS2 via angle-resolved photoemission spectroscopy and in-situ rubidium deposition. At 205 K, the rubidium deposition drives a normal metal-insulator transition via filling electrons into the conduction band. While at 225 K, however, the rubidium deposition drives a bandwidth-controlled Mott transition as characterized by a rapid collapsing of Mott gap and a loss of spectral weight of the lower Hubbard band. Our result, from a doping-controlled perspective, succeeds in distinguishing the metallic, band-insulating, and Mott-insulating phases of 1T-TaS2, manifesting a delicate balance among the electron-itineracy, interlayer-coupling and Coulomb repulsion. We also establish an effective method to tune the balance between these interactions, which is useful in seeking exotic electronic phases and designing functional phase-changing devices.

Key words: angle-resolved photoemission spectroscopy, metal-insulator transition, transition metal dichalcogenides

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

  • 74.25.Jb
74.70.Xa (Pnictides and chalcogenides) 79.60.-i (Photoemission and photoelectron spectra)