An anonymous reader writes: The experimental team, led by LNCMI staff scientist Cyril Proust and Louis Taillefer of the University of Sherbrooke in Canada, used their 90-tesla magnet — which creates a magnetic field nearly two million times as strong as the one enshrouding Earth — to momentarily strip away superconductivity in their cuprate sample. This revealed details of the underlying phase from which the behavior seems to arise.
With the veil lifted, the scientists discovered a sharp change in behavior at what appears to be a “quantum critical point” in cuprates, reminiscent of the freezing point of water. Theorists have long speculated that such a quantum critical point might exist, and that it could play a key role in superconductivity, said Andrey Chubukov, a condensed-matter theorist at the University of Minnesota. “One thing is to say this; another thing is to measure it,” Chubukov said.