Researchers at the University of Cambridge, managed to activate graphene's potential to superconduct by coupling it with a material called praseodymium cerium copper oxide (PCCO). The researchers suggest that superconductive graphene could have interesting applications; It could be used to create new types of superconducting quantum devices for high-speed computing, and it might also be used to prove the existence of a form of superconductivity known as "p-wave" superconductivity, which academics have been struggling to verify for many years.
Graphene's ability to superconduct has been speculated but thus far has only been achieved by doping it with, or by placing it on, a superconducting material - a process that can compromise some of its other properties. "Placing graphene on a metal can dramatically alter the properties so it is technically no longer behaving as we would expect," the team stated. "What you see is not graphene's intrinsic superconductivity, but simply that of the underlying superconductor being passed on."
PCCO is an oxide from a wider class of superconducting materials called "cuprates". It also has well-understood electronic properties, and using scanning and tunnelling microscopy, the researchers were able to distinguish the superconductivity in PCCO from the superconductivity observed in graphene. In this Cambridge study, the team saw a different type of superconductivity in the graphene than in PCCO, meaning that it came from the graphene itself.
It remains unclear what type of superconductivity the team activated, but their results indicate that it is the above-mentioned elusive "p-wave" form. If so, the study could transform the ongoing debate about whether this mysterious type of superconductivity exists, and - if so - what exactly it is.
"If p-wave superconductivity is indeed being created in graphene, graphene could be used as a scaffold for the creation and exploration of a whole new spectrum of superconducting devices for fundamental and applied research areas," the researchers said. "Such experiments would necessarily lead to new science through a better understanding of p-wave superconductivity, and how it behaves in different devices and settings."
The study also has further implications. For example, it suggests that graphene could be used to make a transistor-like device in a superconducting circuit, and that its superconductivity could be incorporated into molecular electronics. "In principle, given the variety of chemical molecules that can bind to graphene's surface, this research can result in the development of molecular electronics devices with novel functionalities based on superconducting graphene," the researchers added.
This work was conducted by Cambridge University, alongside collaborators from the Cambridge Graphene Centre, the Hebrew University of Jerusalem in Israel, and the Norwegian University of Science and Technology in Trondheim,