Scientists have discovered a new state of matter called the ‘Jahn-Teller-metal’ that appears to be an insulator, superconductor, metal and magnet all rolled into one. The research could help develop new molecular materials that are superconductors at even higher temperatures, researchers said.
An international team of researchers made the discovery by studying a superconductor made from carbon-60 molecules or “buckyballs”. The team found the new state after changing the distance between neighbouring buckyballs by doping the material with rubidium, ‘physicsworld.com’ reported.
The study shows that the material has a rich combination of insulating, magnetic, metallic and superconducting phases – including the otherwise unknown state, which has been dubbed as “Jahn–Teller metal”.
The study, led by Kosmas Prassides of Tohoku University in Japan, provides important clues about how the interplay between the electronic structure of the molecules and their spacing within the lattice can strengthen interactions between electrons that cause superconductivity.
Superconductors are a large and diverse group of materials that offer zero resistance to electrical currents when cooled below a critical temperature (TC).
Superconducting lattices of fullerides – C60 plus three alkali-metal atoms – have been studied for more than two decades, and provide an interesting test bed.
This is because the distance between fulleride molecules – and hence the electronic properties of the material – can be adjusted by applying pressure to the material or doping it with different kinds of atoms.
The research involves caesium fulleride (Cs3C60) in a face-centred-cubic lattice with a Cs3C60 molecule at each lattice site.