Graphene expert comments on the creation of an extremely tiny magnetic field detector

“The research group from the University of Basel has recently created an ultracompact superconducting quantum interference device — aka SQUID, where the record miniaturization is achieved by using next-generation materials: bilayer graphene-based van der Waals heterostructures.

SQUIDs usually consist of two superconducting channels, joined into a ring, and separated with Josephson junctions — the latter are basically insulating layers. In superconductors, the electric charge is carried by Cooper pairs of bound electrons, whose behavior obeys a wave function with a given amplitude and phase. When an electric current passes through a SQUID, the flow of Cooper pairs separates into two parts upon entry. The two parts then interfere again as they exit the device. An external magnetic field affects the wave function phases of the Cooper pairs that run along the two channels, making SQUIDs very sensitive to magnetic fields.

The essence of the discovery made at the University of Basel is that using multilayer structures based on 2D materials makes it possible to expand the range of functions of SQUIDs and increase their sensitivity even further. I think we are going to see other new features soon, and that is true not just about SQUIDs but for other devices, too. Scientists are experimenting with various types of 2D materials and nanostructures based on them to make devices smaller and more accurate than ever. Humanity is approaching a new technological revolution, and I am sure there are many more brilliant discoveries to come, that will change our life for the better in the near future,” —  commented Valentyn Volkov, Director of the Center for Photonics and 2D Materials and head of the Nanophotonics and Plasmonics Lab.