Laser ARPES on Orbital Origin of Extremely Anisotropic Superconducting Gap in FeSe Superconductor

ORAL

Abstract

We have carried out high resolution laser-based angle-resolved photoemission (ARPES) measurements on bulk FeSe superconductor (Tc=8~9K). We will report direct observation of highly anisotropic Fermi surface and extremely anisotropic superconducting gap in the nematic state of the FeSe superconductor. We find that the low-energy excitations of the entire hole pocket at the Brillouin zone center are dominated by the single dxz orbital. The superconducting gap exhibits an anticorrelation relation with the dxz spectral weight near the Fermi level. These observations provide new insights in understanding the orbital origin of the extremely anisotropic superconducting gap in the FeSe superconductor and the relation between nematicity and superconductivity in the iron-based superconductors.

*This work is supported by the National Key Research and Development Program of China (Grants No. 2016YFA0300300 and No. 2017YFA0302900), the National Natural Science Foundation of China (Grants No. 11334010 and No. 11534007), the National Basic Research Program of China (Grants No. 2015CB921000 and No. 2015CB921300), and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grants No. XDB07020300 and No. XDPB01).

–

Presenters

  • Cong Li

    • Institute of Physics, Chinese Academy of Sciences

Authors

  • Cong Li

    • Institute of Physics, Chinese Academy of Sciences

  • DeFa Liu

    • Institute of Physics, Chinese Academy of Sciences

  • Jianwei Huang

    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences

  • Bin Lei

    • Department of physics, University of Science and Technology of China

  • Le Wang

    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics

  • Xianxin Wu

    • Institute for Theoretical Physics and Astrophysics, University of Wuerzburg
    • Physics, University of Wurzburg
    • Institute for Theoretical Physics and Astrophysics, Julius-Maximilians University of Wurzburg, Am Hubland, D-97074 Wurzburg, Germany
    • Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg
    • Institute of Physics, Chinese Academy of Sciences
    • Univ of Wuerzburg
    • Institute for Theoretical Physics, University of Wuerzburg
    • Univ of Wurzburg

  • Qiang Gao

    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences
    • The Chinese Academy of Sciences, Institute of physics

  • Yuxiao Zhang

    • Institute of Physics, Chinese Academy of Sciences

  • Xu Liu

    • Institute of Physics, Chinese Academy of Sciences

  • Yong Hu

    • Institute of Physics, Chinese Academy of Sciences

  • Lin Zhao

    • National Laboratory for Superconductivity (NLSC), Institute of Physics, CAS
    • Institute of Physics, Chinese Academy of Sciences

  • Shaolong He

    • Institute of Physics, Chinese Academy of Sciences

  • Guodong Liu

    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences
    • The Chinese Academy of Sciences, Institute of physics

  • Xiaoli Dong

    • Institute of Physics, CAS
    • Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
    • Institute of Physics, Chinese Academy of Sciences

  • Xiaowen Jia

    • Institute of Physics, Chinese Academy of Sciences

  • Youguo Shi

    • Institute of Physics, Chinese Academy of Sciences
    • Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences
    • Institute of Physics

  • Jiangping Hu

    • Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences
    • Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China

  • Tao Xiang

    • Chinese Academy of Sciences (CAS), China
    • Institute of Physics
    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics, CAS
    • Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190, China

  • Xianhui Chen

    • University of Science and Technology of China
    • Department of physics, University of Science and Technology of China

  • Zuyan Xu

    • Technical Institue of Physics and Chemistry, Chinese Academy of Sciences

  • Chuangtian Chen

    • Technical Institue of Physics and Chemistry, Chinese Academy of Sciences

  • Xingjiang Zhou

    • Chinese Academy of Sciences (CAS)
    • Institute of Physics, Chinese Academy of Sciences
    • National Laboratory for Superconductivity (NLSC), Institute of Physics, CAS
    • Chinese Academy of Sciences
    • The Chinese Academy of Sciences, Institute of physics