Charlie Wood in Quanta:
For decades, a family of crystals has stumped physicists with its baffling ability to superconduct — that is, carry an electric current without any resistance — at far warmer temperatures than other materials.
Now, an experiment years in the making has directly visualized superconductivity on the atomic scale in one of these crystals, finally revealing the cause of the phenomenon to nearly everyone’s satisfaction. Electrons appear to nudge each other into a frictionless flow in a manner first suggested by a venerable theory nearly as old as the mystery itself.
“This evidence is really beautiful and direct,” said Subir Sachdev, a physicist at Harvard University who builds theories of the crystals, known as cuprates, and was not involved in the experiment.