Direct observation of vortices in infinite-layer nickelate superconductors

ORAL

Abstract

We use a scanning SQUID (Superconducting QUantum Interference Device) to study local magnetic properties of an infinite-layer nickelate Nd0.85Sr0.15NiO2 thin film grown on LSAT ((LaAlO3)0.3(Sr2TaAlO6)0.7) substrate, and a Nd0.775Sr0.225NiO2 thin film grown on SrTiO3. We find a reduced number of magnetic inclusions for nickelates grown on LSAT, in contrast to the ferromagnetic background caused by NiOx nano-particles in nickelate films grown on SrTiO3. The reduced ferromagnetic background allows us to see superconducting vortices by imaging their magnetic field a few micrometers above the sample. The extrapolated Pearl length from fitting vortices (~ 400 um at 3 K) agrees with local susceptibility measurements. This Pearl length translates to a 1.1 um in-plane penetration depth for a thin film of 7 nm. Our study confirms the improved sample quality of nickelates grown on LSAT, and to our knowledge, is the first to reveal superconducting vortices in this recently discovered superconductor.

*This work was supported by the Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-76SF00515.

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Publication: Scanning SQUID study of ferromagnetism and superconductivity in infinite layer nickelates

Presenters

  • Ruby A Shi

    • Stanford University
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory

Authors

  • Ruby A Shi

    • Stanford University
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory

  • Kyuho Lee

    • Stanford University
    • Stanford University, SLAC National Accelerator Laboratory

  • Bai Yang Wang

    • Stanford University
    • Stanford University, SLAC National Accelerator Laboratory

  • Yusuke Iguchi

    • Stanford University
    • Stanford university
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory

  • Harold Hwang

    • Stanford Univ
    • Stanford University

  • Kathryn A Moler

    • Stanford University
    • Stanford Univ
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory