Most people are now familiar with the term “superconductor” -- a
material which possesses practically no resistance to electricity,
theoretically able to sustain a closed system indefinitely without external
power. Unfortunately, there are presently no known superconductors that work at
room temperature, most only at a few degrees above absolute zero.
Superinsulators are not something one often reads about.
There were no known such materials, in fact, until researchers at the U.S.
Department of Energy's Argonne National Laboratory produced one. A
superinsulator, just as it sounds, works in exactly the opposite manner as a
superconductor – very minimal to no current will pass through it.
The researchers found that a certain material, a thin film
of titanium nitride, experienced a resistance increase of 100,000 percent as
its temperature or the external magnetic field dropped below a certain
threshold. Led by Valerii Vinokur of Argonne and Russian scientist Tatyana
Baturina, the group of scientists used a dilution refrigerator to cool the
sheet to near absolute zero temperature to make their observations.
Interestingly, the gimmick to superinsulators is virtually
the same as for superconductors, relying on electron pairing known as Cooper
pairs. These stable electron pairs form long chains in superconductors,
allowing the near infinitely free flow of current. Conversely, in superinsulators,
the Cooper pairs instead of linking together remain completely independent,
thus inhibiting the flow of current nearly infinitely.
The group found that the difference between superconducting
and superinsulating materials in this case is dependent on the thickness of the
film. Several materials aside from titanium nitride also act in this manner,
though none at room temperature.
In the future, superconducting and superinsulating materials
could be combined to create a perfect theoretical self-sustaining circuit, high
current transmission lines with no leakage, or high performance batteries just
to name a few. A viable material with acceptable production costs would likely
harbinger a revolution in electrical devices of all kinds and industries.