Graphene is an incredible ingredient. It is only one atom thick, yet 200 times stronger than steel. It is a forgery of carbon atoms and can handle electricity. Under proper conditions, it is a superconductor, so that the electric current does not face any resistance.
We only know about graphene’s superconductivity since 2018. Two layers of graphene placed on top of each other. These were not completely overloaded; they had a slight bend of 1.1 degrees. The layers have cooled a bit above absolute zero, and voila superconductive graphene. As published in Science, the new work has added an extra layer of graphene. The superconductivity of this graphene sandwich achieved with a slightly different twist angle (1.56 degrees on average), but up to higher temperatures – although still a few degrees above absolute zero. The searches are interesting in themselves as we learn more about graphene. However, it has a wide range of effects. It helps researchers study superconductivity in completely new ways.
Three-layer graphene superconductors are sensitive to externally applied electric fields. By adjusting the energy of this field, researchers can control the level of superconductivity of the system. Researchers now have a suitable way to study superconductivity. “Superconductivity in spiral graphene provides physicists with an experimentally controllable and theoretically accessible model system where they can play with system properties to decode the mysteries of high-temperature superconductivity,” said Harvard Bibb, a co-lead author of the paper. “This has enabled us to observe superconductors to a new level and provided us with important clues about the method by which superconductivity operates,” Harvard PhD student Zeyu Hao added to the study.
The Holy Grail of Superconductivity is creating an element that conducts superconducting in indoor conditions. Last year, the first component superconducting at room temperature announced, but there are a few complications. It was a small amount of material, and to be a superconductor it pressed between two diamonds at a pressure of 2.5 million atmospheres. It does not really scream “wonder-material that will change our lives”.
New tri-layer graphene has shown evidence that its superconductivity driven by strong interactions between electrons. This process considered extremely important in the manufacture of stable, high-temperature superconductors, but they fully understood. This system can provide important insights into the theory of superconductivity. “The more we understand, the more opportunities there will be to increase the temperature of the superconducting transition,” Kim said.
