On the Tc enhancement mechanism at the FeSe/SrTiO3 interface

ORAL

Abstract

At the interface between monolayer FeSe films and STO substrate the superconducting transition temperature (Tc) is unexpectedly high. The mechanism for the Tc enhancement has been the central question, as it may present a new strategy for seeking out higher Tc materials.
To reveal the mechanism, by combining advances in high quality interface growth, 16O-18O isotope substitution, and extensive data from angle resolved photoemission spectroscopy, we provide striking evidence that the high Tc in FeSe/STO is the cooperative effect of the intrinsic pairing mechanism in the FeSe and interactions between the FeSe electrons and STO phonons.
Furthermore, our results point to the promising prospect that similar cooperation between different Cooper pairing channels may be a general framework to understand and design HTSCs.

*The National Key R&D Program of the MOST of China (Grant Nos. 2016YFA0300200, 2017YFA0303004);
The National Science Foundation of China (Grant Nos. 11704073, 11504342).
Discussions with:
Profs. Dragan Mihailovic, Hugo Keller, Annette Bussmann-Holder, Frederick Walker, and Victor E. Henrich on the isotope effects;
Guangming Zhang, Qianghua Wang, and Steve Johnston on EPI.
Dr. Darren Peets for help with the editing.
Dr. Qiuyun Chen for help with the SIMS measurements.

Presenters

  • Tianlun Yu

    • Physics, Fudan University

Authors

  • Tianlun Yu

    • Physics, Fudan University
  • Qi Song

    • Harvard University
    • Physics, Fudan University
  • Xia Lou

    • Physics, Fudan University
  • Binping Xie

    • Laboratory of Advanced Materials, Fudan University
  • Hai chao Xu

    • Physics, Fudan University
    • Fudan University
  • Chenhaoping Wen

    • Physics, Fudan University
  • Qi Yao

    • Physics, Fudan University
  • Shuyuan Zhang

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

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

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

    • Physics, Fudan University
    • Fudan University
  • Donglai Feng

    • Fudan University
    • Physics, Fudan University