Interface engineering of superconductor/normal metal heterostructures: the critical role of interface on proximity and inverse effect

ORAL

Abstract

We investigate the crucial role of interface on superconducting proximity and its inverse effect, using epitaxially grown vertical/lateral superconductor/normal metal (S/N) heterostructures. The two different S/N heterostructures have utterly different interface nature: one is transparent and the other opaque. Because of the electrically transparent interface of the vertical heterostructure, electrons fully coherence in the vertical S/N heterostructure. Local tunneling spectroscopy and global superfluid density measurement show the uniform superconducting gap (SCG) throughout whole vertical S/N heterostructure with no discontinuity. In contrast, lateral S/N heterostruture reveals the spatial dependent SCG with an abrupt discontinuity due to the diffuse interface. Moreover, we found that for the vertical heterostructure in Cooper limit, electron-phonon coupling strength weakens as the thickness ratio of Pb to Ag is lower than 2.

*This work was supported by ONR-N00014-14-1-0330, the Welch Foundation (F-1672), and the National Science Foundation DMR-1506678.

Presenters

  • Hyoungdo Nam

    • Physics, University of Texas at Austin
    • Physics, Univ of Texas, Austin
    • Department of Physics, Univ of Texas, Austin

Authors

  • Hyoungdo Nam

    • Physics, University of Texas at Austin
    • Physics, Univ of Texas, Austin
    • Department of Physics, Univ of Texas, Austin
  • Chendong Zhang

    • Department of Physics, Univ of Texas, Austin
  • Siyuan Zhu

    • Physics, University of Texas at Austin
    • Department of Physics, Univ of Texas, Austin
  • Jisun Kim

    • Department of Physics, Univ of Texas, Austin
  • Jungdae Kim

    • Department of Physics,BRL, and EHSRC, University of Ulsan
    • Department of Physics, Univ of Texas, Austin
  • Hongjun Gao

    • Chinese Academy of Sciences
    • Institue of Physics, Chinese Academy of Sciences
  • Qian Niu

    • Univ of Texas, Austin
    • Physics, University of Texas at Austin
    • Department of Physics, University of Texas at Austin
    • Physics, The University of Texas at Austin
    • Department of Physics, Univ of Texas, Austin
  • Chih-Kang Shih

    • the University of Texas at Austin
    • Physics, University of Texas at Austin
    • Physics, Univ of Texas, Austin
    • Department of Physics, Univ of Texas, Austin
    • Physics, UT Austin
    • Univ of Texas, Austin