If there are two classes of matter that electronics people can agree on, its conductors and insulators. Electrically, conductors and insulators don’t have much in common. The same has held true in the quantum physics world until some research at Princeton has suggested that quantum oscillation — a phenomenon associated with metals — is taking place in an insulator. Scientists aren’t sure what’s really happening yet, but it may suggest there is a new quantum particle yet to be discovered.
In metals, electrons are very mobile which allows a relatively easy flow of electrical current. However, at low temperatures, a magnetic field can shift electrons to a quantum state causing its resistance to change in an oscillating pattern. Insulators generally do not exhibit this effect.
Researchers made a monolayer of tungsten ditelluride using the same kind of adhesive tape process you see to create graphene. In bulk, the material is a conductor but in a monolayer, tungsten ditelluride is an insulator.
The researchers postulate there may be a neutral-charge quantum particle responsible for the effect. We aren’t physics gurus, but we’ll be interested to see if anyone finds this effect in an insulator that didn’t start off being a conductor. We also aren’t sure how this relates to earlier work with quantum oscillations in Kondo insulators which also took place at Princeton.