Meet the Newest State of Matter
9 May 2015 // 11:30 AM CET
It’s only slightly less exciting than it sounds: a new state of matter. The discovery, which comes courtesy of an international team led by Kosmas Prassides of Tokohu University in Japan, offers a novel material with an unusual combination of properties—insulator, superconductor, metal, magnet. Of particular interest is the hint of high-temperature superconductivity, something of a materials science holy grail and a persistent physics mystery.
So, there are lots of different states of matter. We all know solids, liquids, gases, and, probably, plasmas, but beyond these there’s an entire catalog of matter alternatives: Bose–Einstein condensate, degenerate matter, supersolids/superfluids, quark-gluon plasma, etc. The difference is that all those alternatives are lab-created and don’t have much place out in the real world of nature. The Prassides group’s new material is one of those states, a crystalline arrangement of carbon-60 molecules, better known as buckyballs, doped with rubidium atoms, which are used here to control and maintain distances between the buckyballs, tuning the material’s properties/phases.
It’s in this tuning that we find the new, previously unknown state or states of matter, which are known as a “Jahn–Teller metals” after the Jahn-Teller effect, which relates structural deformations among molecules found within a material to its electrical properties. Put simply, by applying or removing pressure, it’s possible to boost the conductivity of what may have been an insulator at lower pressures. High pressure: conductivity.