Given its ability to become an insulator and a superconductor just by varying the applied pressure, are Jahn-Teller metals qualify as a new form of matter?
By: Ringo Bones
Back in May 12, 2015, researchers at Japan’s Tohoku University are making a bold claim saying that they had discovered an entirely new form of matter. The team led by Kosmas Prassides, says they’ve created what’s called a Jahn-Teller metal by inserting atoms of rubidium – a strange alkali metal more chemically reactive than pure metallic sodium – into buckyballs or buckminsterfullerene, a pure carbon structure which has a spherical shape formed from a series of interlocking polygons of carbon atoms. Buckyballs, which are somewhat related to other carbon supermaterials like graphene and carbon nanotubes, are already known for their superconductive capabilities. Here, while combining buckyballs and rubidium, the researchers created a complex crystalline structure that seemed to conduct, insulate and magnetize while acting as a metal. It goes beyond what ordinary matter can do.
Jahn-Teller metals have recently created a buzz in the scientific community because such esoteric form of matter could serve as a key to understanding one of the biggest mysteries in physics that has baffled them since the late 1980s – i.e. the phenomenon of high-temperature superconductivity. Named after the Jahn-Teller Effect which is used in chemistry to describe how at low pressures the geometric arrangement of molecules and ions in an electronic state can become distorted. This new state of matter allows scientists to transform an insulator – which can’t conduct electricity – into a conductor by simply applying pressure. Could Jahn-Teller metals be used in constructing a new generation of piezoelectric materials for use in high fidelity audio someday?