Most people are familiar with some of the common states of matter: solids, liquids and gases. Scientists also recognize a fourth state of matter — plasma — that is commonly observable here on Earth, as well as a host of other states that can only be created in the lab, such as Bose–Einstein condensates and neutron-degenerate matter. Jahn-Teller metals can now be added to this list, a state which appears to have the properties of an insulator, superconductor, metal and magnet all wrapped into one.
It's the material's superconductivity which might be the most interesting trait, however. It has the potential to achieve superconductivity at a relatively high critical temperature ("high" as in -135 degrees Celsius as opposed to the sub -243.2 degrees Celsius required by many ordinary metallic superconductors), which is significant for the science of superconductivity. Superconductors conduct electricity without resistance, so they have the potential to revolutionize how we use and produce energy. But these technologies become far more feasible if developed using high-temperature superconductivity.
A team led by chemist Kosmas Prassides from Tokohu University in Japan produced the new state of matter by introducing rubidium into carbon-60 molecules — more commonly known as "buckyballs" — which altered the distance between molecules. This essentially ramps up the pressure inside the material, transforming it from an insulator to a metal.
What the researchers observed, however, was that when an insulator becomes a metal, there is a transitional phase where the molecules hang on to their old shapes. So the material still looks like an insulator, but electrons nevertheless manage to hop around freely as if it were a conductor. It's this transitional phase where the material takes the form of a Jahn-Teller metal, a state which is both an insulator and conductor at the same time.
Of course, it will take oodles of more study before this new state of matter might be reasonably controlled and understood before any real-life, revolutionary applications can be developed out of it. But if you're a geek for science it's impossible not to be excited by this discovery — a new state of matter! The potential breakthroughs in the science of superconductivity alone is reason to feel exhilarated.
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