Reversing the direction of the supercurrent in a controllable Josephson junction

J. J. A. Baselmans (), A. F. Morpurgo, B. J. van Wees and T. M. Klapwijk
Additional contact information
J. J. A. Baselmans: University of Groningen
A. F. Morpurgo: University of Groningen
B. J. van Wees: University of Groningen
T. M. Klapwijk: University of Groningen

Nature, 1999, vol. 397, issue 6714, 43-45

Abstract: Abstract When two superconductors are connected by a weak link, a supercurrent flows, the magnitude of which is determined by the difference in the macroscopic quantum phases of the superconductors. This phenomenon was discovered by Josephson1 for the case of a weak link formed by a thin tunnel barrier: the supercurrent, I, is related to the phase difference, π, through the Josephson current–phase relation, I = Icsinπ, with Ic being the critical current which depends on the properties of the weak link. A similar relation holds for weak links consisting of a normal metal, a semiconductor or a constriction2. In all cases, the phase difference is zero when no supercurrent flows through the junction, and increases monotonically with increasing supercurrent until the critical current is reached. Here we use nanolithography techniques to fabricate a Josephson junction with a normal-metal weak link in which we have direct access to the microscopic current-carrying electronic states inside the link. We find that the fundamental Josephson relation can be changed from I = Icsinπ to I = Icsin(π + π)—that is, a π-junction—by controlling the energy distribution of the current-carrying states in the normal metal. This fundamental change in the way these Josephson junctions behave has potential implications for their use in superconducting electronics as well as in (quantum) logic circuits based on superconductors.

Date: 1999
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/16204 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:397:y:1999:i:6714:d:10.1038_16204

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/16204

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().