In April an international team of scientists introduced a new fundamental state of matter: superinsulating. Just as a superconducting material allows a current to pass through it without any resistance, a superinsulating material can hold a charge infinitely long without leakage.
Valerii Vinokur, a physicist at Argonne National Laboratory in Illinois, co-led the team that made the superinsulator [subscription required] out of a film of titanium nitride, an extremely hard ceramic material. At low temperature titanium nitride can have two very different sets of traits—either a superconductor or an insulator—depending on the thickness of the film. When the material is just thin enough, it switches from superconducting to insulating. But cooling the film more revealed a third state: a superinsulator. “The observation came as a complete surprise,” Vinokur says.
The superinsulating capacity of titanium nitride occurs only at supercold temperatures, within one-tenth of one degree of absolute zero, the temperature at which all motion ceases. Superinsulation thus joins the ranks of other bizarre phases of matter that exist under extreme conditions, like superconductivity and Bose-Einstein Condensate (a condition in which, at almost absolute zero, large groups of atoms blur together into a single quantum state).
Vinokur says he hopes to find ways to increase the temperature and make superinsulators commercially useful. Other materials could be used in addition to titanium nitride, and superconducting wires could be surrounded by superinsulators, creating a “supercircuit” that would generate no heat and keep a current infinitely long. Possibilities are super—just super.