Maura Sassetti

Superconducting Quantum Interference Devices based on InSb nanoflag Josephson junctions

  1. Andrea Chieppa,
  2. Gaurav Shukla,
  3. Simone Traverso,
  4. Giada Bucci,
  5. Valentina Zannier,
  6. Samuele Fracassi,
  7. Niccolo Traverso Ziani,
  8. Maura Sassetti,
  9. Matteo Carrega,
  10. Fabio Beltram,
  11. Francesco Giazotto,
  12. Lucia Sorba,
  13. and Stefan Heun
Planar Josephson junctions (JJs) based on InSb nanoflags have recently emerged as an intriguing platform in superconducting electronics. This letter presents the fabrication and investigation
of superconducting quantum interference devices (SQUIDs) employing InSb nanoflag JJs. We provide measurements of interference patterns in both symmetric and asymmetric geometries. The interference patterns in both configurations can be modulated by a back-gate voltage, a feature well reproduced through numerical simulations. The observed behavior aligns with the skewed current-phase relations of the JJs, demonstrating significant contributions from higher harmonics. We explore the magnetic field response of the devices across a wide range of fields (±30 mT), up to the single-junction interference regime, where a Fraunhofer-like pattern is detected. Finally, we assess the flux-to-voltage sensitivity of the SQUIDs to evaluate their performance as magnetometers. A magnetic flux noise of S1/2Φ=4.4×10−6Φ0/Hz‾‾‾√ is identified, indicating potential applications in nanoscale magnetometry.
arxiv pdf