Quantum Cooper pairs linger in uranium ditelluride post-superconductivity

Physicists at the University of Illinois Urbana-Champaign’s Grainger College of Engineering have observed Cooper pairs persisting in the metal uranium ditelluride even after superconductivity ceases. These pairs organize into patterns called pair density waves, predicted two decades ago but never before directly observed to remain once superconductivity vanishes. “Pair density waves are the Cheshire Cat’s grin of superconductivity,” explains Eduardo Fradkin, an Illinois Grainger Engineering physics professor and project co-lead; they are a vestige of the superconducting phase itself. This research, published in the Proceedings of the National Academy of Sciences, offers new insight into unconventional superconductivity and…