Imaging local supercurrent density in planar Josephson junction [Part 1]
ORAL
Abstract
Josephson junctions exhibit macroscopic coherent quantum tunneling and are central
superconducting elements that are widely used for quantum sensing and quantum technology
applications. However, direct imaging of the coherent interference of supercurrent flow in the
junction is still missing. Here, using a scanning Nitrogen-vacancy center in diamond, we report high
resolution, direct visualization of Josephson vortices in a diffusive superconducting-normal-
superconducting (SNS) junction. The supercurrent flow evolves with external current bias and threaded
flux, as the phase difference of the superconducting electrodes is tuned. We establish local scanning
magnetometry as a feasible way to measure Josephson junctions made of quantum materials.
superconducting elements that are widely used for quantum sensing and quantum technology
applications. However, direct imaging of the coherent interference of supercurrent flow in the
junction is still missing. Here, using a scanning Nitrogen-vacancy center in diamond, we report high
resolution, direct visualization of Josephson vortices in a diffusive superconducting-normal-
superconducting (SNS) junction. The supercurrent flow evolves with external current bias and threaded
flux, as the phase difference of the superconducting electrodes is tuned. We establish local scanning
magnetometry as a feasible way to measure Josephson junctions made of quantum materials.
*This work is supported by MURI under grant no. W911NF2120147 and ARO under grant no. W911NF-22-1-0248.
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Presenters
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Seunghyun Park
- Harvard University