Editor's Summary
3 April 2008
Better than insulating
The introduction of disorder into thin superconducting films induces a droplet-like electronic texture, with superconducting islands immersed in a normal matrix. By fine-tuning this disorder, the system can be transformed from superconductor to insulator. A paper in this issue presents experimental evidence for the involvement of a previously uncharacterized 'superinsulating' state of matter in this process, a 'mirror image' equivalent of a superconductor with infinite resistance. During the transition from superconductor to insulator, a distinct conductivity state is formed, a Cooper-pair insulator, with thermally activated conductivity. Experiments in titanium nitride films show that at a certain finite temperature, a Cooper-pair insulator becomes a superinsulator, a state resembling superconductivity in that it is destroyed by a sufficiently strong critical magnetic field, and breaks down at some critical voltage.
News and Views: Condensed-matter physics: Opposite of a superconductor
Magnetism and superconductivity are caused by spontaneous ordering on a macroscopic scale. Studies of a two-dimensional superconductor reveal another striking example of such behaviour — superinsulation.
Rosario Fazio
doi:10.1038/452542a
Letter: Superinsulator and quantum synchronization
Valerii M. Vinokur, Tatyana I. Baturina, Mikhail V. Fistul, Aleksey Yu. Mironov, Mikhail R. Baklanov & Christoph Strunk
doi:10.1038/nature06837