Magnetic Imaging of Proximity and Vortex Phenomena in Superconducting Devices

ORAL

Abstract

Superconducting devices play a crucial role in modern science and technology, forming the foundation of ultrasensitive sensors, precision metrology systems, and advanced computing platforms. One key application lies in millimeter-wave astronomy, where superconducting detectors serve as the primary sensing elements for cosmological observations. Among the most widely used devices in this field are transition-edge sensors (TESs) and kinetic inductance detectors (KIDs). In this work, we employ scanning superconducting quantum interference device (SQUID) microscopy to directly image the local superconducting properties of these sensors. Specifically, we visualize both the direct and inverse superconducting proximity effects in Al-Mn and Mo/Au bilayer TESs and model the observed phenomena by solving the Usadel and Ginzburg–Landau equations for the relevant geometries. For Al-based KIDs, we image the vortex configurations across different regions of the device and directly correlate variations in the resonant frequency and quality factor with the local vortex density. Together, these results highlight the utility of local magnetic imaging as a tool for elucidating the mesoscopic behavior of superconducting devices, providing valuable insights into their performance and design.

*This work was supported by the Air Force Research Laboratory, Project Grant FA9550-21-1-0429. S. Walker acknowledges support by the National Science Foundation Award No. 2503181.

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Presenters

  • Austin R Kaczmarek

    • Cornell University

Authors

  • Austin R Kaczmarek

    • Cornell University

  • Samantha Walker

    • Cornell University

  • Darshan Patel

    • Cornell University

  • Jason Austermann

    • National Institute of Standards and Technology Boulder
    • National Institute of Standards and Technology
    • NIST

  • Douglas A Bennett

    • National Institute of Standards and Technology (NIST)
    • National Institute of Standards and Technology, Boulder, Colorado 80305, USA
    • National Institute of Standards and Technology Boulder
    • National Institute of Standards and Technology, Boulder

  • Kelsey M Morgan

    • National Institute of Standards and Technology
    • NIST

  • Daniel Swetz

    • National Institute of Standards and Technology

  • Dan Schmidt

    • National Institute of Standards and Technology, Boulder, Colorado 80305, USA
    • National Institute of Standards and Technology Boulder
    • NIST

  • Shannon M Duff

    • National Institute of Standards and Technology (NIST)
    • National Institute of Standards and Technology, Boulder, Colorado 80305, USA
    • National Institute of Standards and Technology Boulder
    • NIST

  • Johannes Hubmayr

    • National Institute of Standards and Technology Boulder
    • National Institute of Standards and Technology
    • NIST

  • Jordan D Wheeler

    • National Institute of Standards and Technology Boulder

  • Michael Vissers

    • National Institute of Standards and Technology Boulder
    • National Institute of Standards and Technology
    • National Institute of Standards and Technology, Boulder

  • Anna Vaskuri

    • NIST

  • Joel C Weber

    • University of Colorado Boulder
    • NIST

  • Joel N Ullom

    • National Institute of Standards and Technology Boulder
    • National Institute of Standards and Technology, Boulder, Colorado 80305, USA

  • Michael D Niemack

    • Cornell University

  • Katja C Nowack

    • Cornell University