Superconductors are materials that conduct electrical current with practically no electrical resistance at all. This ability makes them extremely interesting and attractive for a plethora of applications such as loss-less power cables, electric motors and generators, as well as powerful electromagnets that can be used for MRI imaging and for magnetic levitating trains. Now, researchers from Nagoya University have detailed the superconducting nature of a new class of superconducting material, magic-angle twisted bilayer graphene.
For a material to behave as a superconductor, low temperatures are required. Most materials only enter the superconducting phase at extremely low temperatures, such as −270°C, which is lower than those measured in outer space. This severely limits their practical applications because such extensive cooling requires very expensive and specialized liquid helium cooling equipment. This is the main reason superconducting technologies are still in their infancy.
High temperature superconductors (HTS), such as some iron and copper-based examples, enter the superconducting phase above −200°C, a temperature that is more readily achievable using liquid nitrogen which cools down a system to −195.8°C. However, the industrial and commercial applications of HTS have been thus far limited. Currently known and available HTS materials are brittle ceramic materials that are not malleable and cannot be made into useful shapes like wires. In addition, they are notoriously difficult and expensive to manufacture. This makes the search for new superconducting materials critical and a strong focus of research for physicists like Prof. Hiroshi Kontani and Dr. Seiichiro Onari from the Department of Physics, Nagoya University.
