Capping layer influence and isotropic in-plane upper critical field of the superconductivity at the FeSe/SrTiO3 interface

ORAL

Abstract

Understanding the superconductivity at the interface of FeSe/SrTiO3 is a problem of great contemporary interest due to the significant increase in critical temperature (Tc) compared to that of bulk FeSe. We report a study of the influence of a capping layer on superconductivity in thin films of FeSe grown on SrTiO3 using molecular beam epitaxy. Our results show that FeTe provides an optimal cap that barely influences the inherent Tc found in pristine FeSe/SrTiO3. In addition, ex situ magnetoresistance measurements are done in FeTe-capped FeSe films to extract the angular dependence of the in-plane upper critical magnetic field. Our observations reveal an almost isotropic in-plane upper critical field, providing insight into the symmetry and pairing mechanism of high temperature superconductivity in FeSe.

*This research was carried out using the Penn State Two-Dimensional Crystal Consortium-Materials Innovation Platform under NSF Grant No. DMR-1539916. YL acknowledges support from the University of Chicago. AR and NS acknowledge support from NSF Grant No. DMR-1539916. RX acknowledges support from the Institute for Quantum Matter under DOE EFRC grant DE-SC0019331. QL acknowledges support from DOE grant No. DE-FG02-08ER46531.

Presenters

  • Yanan Li

    • Pennsylvania State University

Authors

  • Yanan Li

    • Pennsylvania State University
  • Ziqiao Wang

    • Pennsylvania State University
  • Run Xiao

    • Pennsylvania State University
    • Physics, Pennsylvania State University
  • Qi Li

    • Pennsylvania State University
  • Ke Wang

    • Pennsylvania State University
    • Materials Research Institute, The Pennsylvania State University
  • Anthony R. Richardella

    • Pennsylvania State University
    • Physics, The Pennsylvania State University
    • The Pennsylvania State University
    • Physics, Pennsylvania State University
  • Jian Wang

    • Peking University
  • Nitin Samarth

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Physics, Pennsylvania State University
    • The Pennsylvania State University