Graphene isn’t normally a superconductor, but with the right conditions, the electrodes can “leak” their superconductivity into the graphene.
The researchers spent years fine-tuning their process to achieve those conditions. Their device’s geometry, materials, and engineering had to be just right."
Isn't that interesting! Graphene, or at least a very small 150nm-scale "nano surface" of Graphene becoming a superconductor under the right conditions! It'll be interesting to see where that goes in the future...