近日，美国哈佛大学Yao, N. Y.团队揭示了La₃Ni₂O₇中非均相超导性的来源。2026年2月25日出版的《自然》杂志发表了这项成果。

长期以来，镍酸盐超导体家族一直作为高温铜氧化物超导体的类似物被广泛探索。然而，近期发现某些化学计量比的镍酸盐在高压下具有高临界温度（T_c）的超导电性，这一结果令人意外。超导态背后的微观机制在实验上仍不清晰。除了高压环境带来的实验挑战外，典型样品表现出异常微弱的抗磁响应，这被推测为反映了不均匀的"丝状"超导态。

研究组利用集成在金刚石对顶砧中的氮-空位量子传感器，采用宽场、高压、光学探测磁共振谱技术，对原位生长的La₃Ni₂O₇样品的局域抗磁响应进行成像。这些图像证实了在数微米尺度上，功能性超导响应存在显著的不均匀性。通过将抗磁迈斯纳响应与同样原位成像的局域张量应力环境以及化学计量比组成进行空间关联，研究组揭示了抑制和增强超导性的主导机制。该宽场技术同时提供了样品行为的宏观视野和卓越的局域灵敏度，能够根据在亚微米像素尺度观测到的局域结构-功能关联，快速构建多参数相图。

附：英文原文

Title: Uncovering origins of heterogeneous superconductivity in La3Ni2O7

Author: Mandyam, S. V., Wang, E., Wang, Z., Chen, B., Jayarama, N. C., Gupta, A., Riesel, E. A., Levitas, V. I., Laumann, C. R., Yao, N. Y.

Issue&Volume: 2026-02-25

Abstract: The family of nickelate superconductors have long been explored as analogues of the high-temperature cuprates1,2,3,4,5,6. Nonetheless, the recent discovery that certain stoichiometric nickelates superconduct up to high critical temperatures (Tc) under pressure came as a surprise7,8,9,10,11,12,13. The mechanisms underlying the superconducting state remain experimentally unclear. Apart from the practical challenges posed by working in a high-pressure environment, typical samples exhibit anomalously weak diamagnetic responses, which have been conjectured to reflect inhomogeneous ‘filamentary’ superconducting states7,9,14,15,16,17. Here we perform wide-field, high-pressure, optically detected magnetic resonance spectroscopy to image the local diamagnetic responses of as-grown La3Ni2O7 samples in situ, using nitrogen vacancy quantum sensors embedded in the diamond anvil cell18,19,20,21,22,23. These maps confirm marked inhomogeneity of the functional superconducting responses at the few μm scale. By spatially correlating the diamagnetic Meissner response with both the local tensorial stress environment, also imaged in situ, and stoichiometric composition, we show the dominant mechanisms suppressing and enhancing superconductivity. Our wide-field technique simultaneously provides a broad view of sample behaviour and excellent local sensitivity, enabling the rapid construction of multi-parameter phase diagrams from the local structure–function correlations observed at the sub-μm pixel scale.

DOI: 10.1038/s41586-025-10095-x

Source: https://www.nature.com/articles/s41586-025-10095-x