← Back to search

Highly linear proximity-based double-loop SQUID operating above 4 K

G. Trupiano, E. Riccardi, C. Puglia, M. Kiczynski, A. Gardin, G. De Simoni, G. C. Tettamanzi, F. Giazotto

DOI 10.1103/m4wn-d31t · Physical Review Applied

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We demonstrate a highly linear superconducting quantum interference device (SQUID) interferometer based on a double-loop (Bi-SQUID) architecture incorporating three superconductor-normal metal-superconductor (S-N-S) junctions. Fabricated using niobium-gold technology, the device exhibits robust operation at liquid helium temperatures, with a superconducting transition temperature of 8.5 K. The dc flux-to-voltage transfer function demonstrates sharp, symmetric, and highly linear behavior at temperatures up to 5 K. Bi-SQUIDs featuring our single-element S-N-S design represent an interesting and original approach to this field, as they exhibit a numerically estimated spurious-free dynamic range linearity exceeding 60 dB, achieved in a single element, simplifying the requirements in terms of arrays containing hundreds of junctions. These results highlight the potential of proximity-based Bi-SQUIDs for compact and highly linear cryogenic interferometric devices, motivating future investigations of their dynamic and noise performance for applied implementations such as quantum sensing, magnetometry, and biomedical diagnostics.

Source-reported materials — not catalogue approval

FormulaReported Tc (K)Pressure (GPa)Type
Nb

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

8.5Pressure not reportedunknown

Similar papers