中国物理B ›› 2022, Vol. 31 ›› Issue (11): 117402-117402.doi: 10.1088/1674-1056/ac7a10

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Optical study on topological superconductor candidate Sr-doped Bi2Se3

Jialun Liu(刘佳伦)1, Chennan Wang(王晨南)2,†, Tong Lin(林桐)2, Liye Cao(曹立叶)1, Lei Wang(王蕾)1, Jiaji Li(李佳吉)1, Zhen Tao(陶镇)1, Nan Shen(申娜)1, Rina Wu(乌日娜)1, Aifang Fang(房爱芳)1, Nanlin Wang(王楠林)2,3, and Rongyan Chen(陈荣艳)1,‡   

  1. 1 Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China;
    2 International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China;
    3 Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • 收稿日期:2022-02-18 修回日期:2022-06-14 接受日期:2022-06-18 出版日期:2022-10-17 发布日期:2022-10-17
  • 通讯作者: Rongyan Chen E-mail:rychen@bnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12074042 and 11704033), the National Key Research and Development Program of China (Grant Nos. 2021YFA1400400 and 2016YFA0302300), and the Fundamental Research Funds for the Central Universities.

Optical study on topological superconductor candidate Sr-doped Bi2Se3

Jialun Liu(刘佳伦)1, Chennan Wang(王晨南)2,†, Tong Lin(林桐)2, Liye Cao(曹立叶)1, Lei Wang(王蕾)1, Jiaji Li(李佳吉)1, Zhen Tao(陶镇)1, Nan Shen(申娜)1, Rina Wu(乌日娜)1, Aifang Fang(房爱芳)1, Nanlin Wang(王楠林)2,3, and Rongyan Chen(陈荣艳)1,‡   

  1. 1 Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China;
    2 International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China;
    3 Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • Received:2022-02-18 Revised:2022-06-14 Accepted:2022-06-18 Online:2022-10-17 Published:2022-10-17
  • Contact: Rongyan Chen E-mail:rychen@bnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12074042 and 11704033), the National Key Research and Development Program of China (Grant Nos. 2021YFA1400400 and 2016YFA0302300), and the Fundamental Research Funds for the Central Universities.

摘要: Utilizing infrared spectroscopy, we study the charge dynamics of the topological superconductor candidate Sr$_x$Bi$_2$Se$_3$. The frequency-dependent reflectivity $R(\omega$) demonstrates metallic feature and the scattering rate of the free carriers decreases with temperature decreasing. The plasma edge shows a slight blue shift upon cooling, similar to the behavior of Cu$_x$Bi$_2$Se$_3$. As the carrier concentration $n$ obtained by Hall resistivity increases slightly with the decreasing temperature, the effective mass is proved to increase as well, which is in contrast with that of Cu$_x$Bi$_2$Se$_3$.We also perform the ultrafast pump-probe study on the Sr$_{0.2}$Bi$_2$Se$_3$ compounds. Resembling its parent compound Bi$_2$Se$_3$, three distinct relaxation processes are found to contribute to the transient reflectivity. However, the deduced relaxation times are quite different. In addition, the electron-optical-phonon coupling constant is identified to be $\lambda = 0.88$.

关键词: topological superconductor, infrared spectroscopy, ultrafast spectroscopy

Abstract: Utilizing infrared spectroscopy, we study the charge dynamics of the topological superconductor candidate Sr$_x$Bi$_2$Se$_3$. The frequency-dependent reflectivity $R(\omega$) demonstrates metallic feature and the scattering rate of the free carriers decreases with temperature decreasing. The plasma edge shows a slight blue shift upon cooling, similar to the behavior of Cu$_x$Bi$_2$Se$_3$. As the carrier concentration $n$ obtained by Hall resistivity increases slightly with the decreasing temperature, the effective mass is proved to increase as well, which is in contrast with that of Cu$_x$Bi$_2$Se$_3$.We also perform the ultrafast pump-probe study on the Sr$_{0.2}$Bi$_2$Se$_3$ compounds. Resembling its parent compound Bi$_2$Se$_3$, three distinct relaxation processes are found to contribute to the transient reflectivity. However, the deduced relaxation times are quite different. In addition, the electron-optical-phonon coupling constant is identified to be $\lambda = 0.88$.

Key words: topological superconductor, infrared spectroscopy, ultrafast spectroscopy

中图分类号:  (Superconducting materials other than cuprates)

  • 74.70.-b
78.30.-j (Infrared and Raman spectra) 78.47.jg (Time resolved reflection spectroscopy)