pair density waves

Researchers report that Cooper pairs — pairs of electrons responsible for superconductivity — can persist above a superconductor's critical temperature within pair density waves. The finding suggests pairing survives in some form even when the material no longer conducts electricity without resistance. Physicists say the observation could reshape understanding of how superconductivity emerges, particularly in unconventional superconductors.

Physicists report finding Cooper pairs surviving above the critical temperature at which a material normally becomes superconducting. The pairs appear within pair density waves, a modulated electronic state, and the discovery is likened to the Cheshire Cat's grin: superconductivity's signature lingering without the superconducting phase itself. The finding challenges assumptions about how the superconducting transition works and may reshape understanding of high-temperature superconductors.