The Wonder Material That Could Finally Conduct Without Limits
If you have followed materials science at all in the last twenty years, you have heard of graphene. It was first isolated in 2004, earning Andre Geim and Konstantin Novoselov the Nobel Prize in Physics, and ever since it has been described in almost reverent terms. Graphene is a sheet of carbon just one atom thick, arranged in a honeycomb lattice. It is stronger than steel, lighter than paper, nearly transparent, and conducts electricity and heat better than almost anything else we know. Scientists have called it a meta-material because it seems to break many of the rules we expect materials to follow.
For all of its incredible properties, there has always been one major prize that graphene had not claimed: superconductivity. A superconductor is a material that can carry an electrical current with absolutely zero resistance. That means no energy is lost as heat, no matter how far the electricity has to travel. If you could make a power line out of a superconductor, you could transmit energy across continents without losing a single watt. Superconducting magnets already make MRI machines and maglev trains possible, and they are considered essential for the future of quantum computers, which need perfectly stable electrical environments to function.
The catch is that most superconductors only work when they are cooled to extremely low temperatures, often hundreds of degrees below zero, which makes them expensive and difficult to use. Finding new superconducting materials, especially ones that are versatile and can be used in modern electronics, is one of the holy grails of physics.
That is why a new study from researchers at the University of Cambridge is so exciting. The team has found a way to coax graphene itself into becoming a superconductor. On its own, graphene does not superconduct, but the Cambridge physicists discovered that when they place it in intimate contact with another material called praseodymium cerium copper oxide, or PCCO, something remarkable happens. PCCO is itself a cuprate superconductor, a member of a family of materials known for superconducting at relatively higher temperatures.
Through what physicists call the proximity effect, the superconductivity from the PCCO essentially leaks into the graphene. The electrons in the graphene begin to pair up in the way that is necessary for resistance-free flow, and the graphene sheet itself begins to behave as a superconductor. The researchers were able to demonstrate this unequivocally, showing that the graphene layer was carrying a supercurrent with no resistance.
The implications are hard to overstate. Graphene is already compatible with modern electronics manufacturing in a way that many other superconductors are not. It is flexible, it can be patterned at the nanoscale, and it can be integrated into chips. Superconducting graphene could become the foundation for a new generation of quantum computing components, where information is carried by superconducting circuits that need to be incredibly fast and perfectly efficient. It could lead to vastly more sensitive medical scanners, more compact and powerful energy storage devices, and a future power grid that does not waste up to 8 percent of its energy as heat during transmission. The full study is published in the journal Nature Communications, and while there is still a long road from a lab demonstration to a product on the shelf, it opens a door that many thought might stay closed for a long time.
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