Abstract
THE classical superconducting quantum interference device (SQUID) is based on the Josephson effect1, and usually consists of a macroscopic superconducting loop with two artificial weak links (Josephson junctions) through which the supercurrent passes by quantum-mechanical tunnelling. Fink et al.2 proposed a new type of SQUID based on a homogeneous mesoscopic superconducting loop, in which interference between the supercurrents passing through the two halves of the ring results in a critical current that varies with the applied magnetic field in an oscillatory manner. Here we describe the experimental observation of these oscillations in a mesoscopic superconducting aluminum loop without artificial weak links. In this new type of quantum interferometer, 'weak-link' regions with a strongly reduced superconducting order parameter appear periodically at half-integer magnetic flux quanta owing to the interplay between the shielding and transport currents in the loop.
Similar content being viewed by others
References
Josephson, B. D. Phys. Lett. 1, 251–253 (1962).
Fink, H. J., López, A. & Maynard, R. Phys. Rev. B26, 5237–5240 (1982).
Fink, H. J., Grünfeld, V. & López, A. Phys. Rev. B35, 35–37 (1987).
de Gennes, P. G. C. R. Acad. Sci. Ser. II 292, 279–282 (1981).
Alexander, S. Phys. Rev. B27, 1541–1557 (1983).
Fink, H. J., Loo, J. & Roberts, S. M. Phys. Rev. B37, 5050–5057 (1988).
Vloeberghs, H., Moshchalkov, V. V., Van Haesendonck, C., Jonckheere, R. & Bruynseraede, Y. Phys. Rev. Lett. 69, 1268–1271 (1992).
Moshchalkov, V. V. et al. Phys. Script. T45, 226–229 (1992).
Little, W. A. & Parks, R. D. Phys. Rev. Lett. 9, 9–13 (1962).
Tinkham, M. Phys. Rev. 129, 2413–2422 (1963).
Arutyunyan, R. M. & Zharkov, G. F. Zh. eksp. teor. Fiz. 78, 1530–1542 (1980); (Engl. transl.) Sov. Phys. JETP 51, 768–774 (1980).
Muller, C. J., van Ruitenbeek, J. M. & de Jongh, L. J. Phys. Rev. Lett. 69, 140–143 (1992).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Moshchalkov, V., Gielen, L., Dhallé, M. et al. Quantum interference in a mesoscopic superconducting loop. Nature 361, 617–620 (1993). https://doi.org/10.1038/361617a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/361617a0
- Springer Nature Limited
This article is cited by
-
Tunable quantum interferometer for correlated moiré electrons
Nature Communications (2024)
-
Vortex Matter in Heterothermal Superconducting Loops
Journal of Superconductivity and Novel Magnetism (2021)
-
Current-induced SQUID behavior of superconducting Nb nano-rings
Scientific Reports (2016)
-
Andreev Oscillations in Normal-Superconducting-Normal Nanostructures
Journal of Superconductivity and Novel Magnetism (2009)
-
Ginzburg–Landau Theory: A Powerful Tool to Study Vortex Matter in Nanostructured Superconductors
Journal of Superconductivity and Novel Magnetism (2007)