Superinsulator
A superinsulator is a material that at low temperatures under certain conditions has an infinite resistance and no current will pass through it. The superinsulating state has many parallels to the superconducting state, and can be destroyed (in a sudden phase transition) by increased temperature, magnetic fields and voltage.
The superinsulating state was first observed in a titanium nitride film in April 2008 by Russian scientists Valerii Vinokur and Tatyana Baturina working at Argonne National Laboratory, United States. Currently it is not known if the superinsulation state they observed means the dielectric permittivity of the material approaches infinity, or whether the material just has zero conduction as would be found in a vacuum.
Other researchers have seen the same phenomenon in disordered indium oxide films, but have proposed a different explanation for their observations.
Both superconductivity and superinsulation are caused by the pairing of conduction electrons at low temperatures into Cooper pairs. In superconductors, all the pairs move in unison, allowing current without resistance. In superinsulators the Cooper pairs avoid each other, preventing current from flowing. A phase diagram showing parallels with superconductivity is here:
Superinsulators could potentially be used to create batteries that do not lose charge when not in use. Combined with superconductors, superinsulators could be used to create electrical circuits with almost no energy lost as heat.
It has been suggested by several authors that the "superinsulator" may not be a fundamentally new state of solid, but is rather caused due to the non-equilibrium heating of the electrons with respect to the phonons at low temperatures. This notion gets support from the fact that the jump in the current-voltage characteristics, a hallmark of the superinsulating state, is also observed in other systems, such as YxSi1−x, where no known superconducting correlations exist.
...
Wikipedia