Breakthroughs of the Year: 2025

For decades, physicists sought cuprate-like high-temperature superconductivity without copper, turning to nickelates as chemically similar candidates. Earlier superconducting nickelates were confined to ultra-thin films at very low temperatures, leaving their relevance uncertain. This work reports SmEuCaNiO2, a copper-free infinite-layer nickelate that superconducts at about 40 K under ambient pressure, doubling the previous nickelate record and establishing the first robust, cuprate-like platform accessible worldwide. The result provides a powerful testbed to probe electron pairing and resistance-free transport, guiding the design of better superconducting materials.

Citation: Nature 642, 58 (2025)

Authors: S.L.E. Chow, Z.Y. Luo, A. Ariando