Superconducting quantum interference devices are made by coupling two superconductors across a non-superconducting medium. In a previous work graphene was demonstrated to serve as an excellent such medium, where the properties of the interference can be controlled electrostatically over large distances and yet in a “ballistic” way (we think it was the first time to observe the Josephson energy of the system to depend linearly on the length of the graphene, which is the ultimate coupling expected).
The properties of the graphene SQUIDs are promising and may help us to build improved circuits and control them in a very efficient and practical way. The latter may turn to be crucial for future technologies that rely on arrays of interfering superconductors.
Graphene – based tuneable SQUIDs, APL 110, 162602