Boundary-Obstructed Topological High-Tc Superconductivity in Iron Pnictides

ORAL

Abstract

Nontrivial topology and unconventional pairing are two central guiding principles in the contemporary search for and analysis of superconducting materials and heterostructure compounds. It is quite rare that a single material compound possesses both non-trivial topological electronic band structure and unconventional pairing. In this work, we will describe an example of such system in iron-based superconductors. We propose to realize high-order topological superconductors, a new topological phase with the gapless modes located at the corner/hinge instead of the edge/surface, in the 112-family of iron pnictides, such as Ca1-xLaxFeAs2 [1], with the great advantage of the Curie temperature above 40K. Our theory provides the microscopic physical mechanism and topological characterization of this topological phase. Our works not only provide a physical understanding of the existing experiments, but also opens a new arena for high-order topological superconductivity with stable corner/hinge Majorana modes in intrinsic superconductors with high Curie temperature.

*C. X. L. acknowledges the support of the Office of Naval Research (Grant No. N00014-18-1-2793), DOE Grant No. DE- 417SC0019064, and the Kaufman New Initiative research grant KA2018-98553 of the Pittsburgh Foundation.

Presenters

  • Chaoxing Liu

    • The department of Physics, Pennsylvania State University
    • Pennsylvania State University
    • Department of Physics, the Pennsylvania State University, University Park

Authors

  • Chaoxing Liu

    • The department of Physics, Pennsylvania State University
    • Pennsylvania State University
    • Department of Physics, the Pennsylvania State University, University Park
  • Xianxin Wu

    • The department of Physics, Pennsylvania State University
    • Chinese Academy of Science
    • Julius-Maximilians University of Wuerzburg
    • Max Planck Institute for Solid State Physics
  • Wladimir Benalcazar

    • The department of Physics, Pennsylvania State University
    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
  • Yinxiang Li

    • University of Shanghai for Science and Technology, Shanghai, Tin Ka-Ping College of Science
  • Ronny Thomale

    • Julius-Maximilians-Universität Würzburg, Institut für Theoretische Physik und Astrophysik
    • Universität Würzburg
    • Julius-Maximilians University of Wuerzburg
    • Wuerzburg University
  • Jiangping Hu

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