Observation of layer-dependent <i>d<sub>xz</sub></i>/<i>d<sub>yz </sub></i>band splittings in the nematic phase of FeSe/SrTiO<sub>3</sub> films

ORAL

Abstract

The effect of interlayer coupling on physical properties of layered materials such as iron-based superconductors is an interesting question. Here, we use angle-resolved photoemission spectroscopy to directly observe the electronic structure of FeSe films with different layers grown on SrTiO3(001) substrates by in situ molecular beam epitaxy. We find two distinct layer-dependent band splittings in the Brillouin zone center and corner, respectively. In the Brillouin zone corner, the band splitting caused by the nematic phase decreases with the increase in the number of layers. On the contrary, the degeneracy of dxz/dyz bands in double-layer FeSe is lifted in multi-layer films and the band splitting in the Brillouin zone center becomes larger with the increase of film thickness. The results of double-layer FeSe grown on SrTiO3 favor the proposal of d-wave nematic order. Our layer-dependent experiments provide limitations for the theoretical study of the nematic phase in FeSe and shed insights for the study of the interplay between nematicity and superconductivity.

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Presenters

  • Xiliang Peng

    • Institute of Physics, Chinese Academy of Sciences

Authors

  • Xiliang Peng

    • Institute of Physics, Chinese Academy of Sciences

  • Kun Jiang

    • Boston College
    • Institute of Physics, Chinese Academy of Sciences
    • Physics, Boston College
    • Department of Physics, Boston College

  • Xianxin Wu

    • Institute for Theoretical Physics, University of Wuerzburg
    • Institut für Theoretische Physik und Astrophysik, Universität Würzburg
    • Physics department, Pennsylvania State University
    • University of Wurzburg
    • Institut für Theoretische Physik und Astrophysik, University of Würzburg

  • Yonghao Yuan

    • Tsinghua University

  • Yaobo Huang

    • Shanghai Synchrotron Radiation Facility

  • Tian Qian

    • Institute of Physics, Chinese Academy of Sciences

  • Wei Li

    • Department of Physics, Tsinghua University
    • Tsinghua University

  • Jiangping Hu

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

  • Ziqiang Wang

    • Boston College
    • Department of Physics, Boston College
    • Physics, Boston College

  • Yujie Sun

    • Institute of Physics, Chinese Academy of Sciences

  • Hong Ding

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