重费米子超导通常发生在近藤杂化与RKKY长程磁有序竞争的量子临界点附近，是研究量子临界涨落驱动非常规超导配对的重要载体。降低晶体结构维度，量子涨落便会增强，若在二维范德华材料中实现重费米子超导，将为研究维度调控的量子临界行为和非常规超导机制提供理想平台。而二维范德华重费米子体系非常少见，近期发现的范德华层状重费米子金属CeSiI为此带来契机。该材料在常压下具有近藤相干态和长程反铁磁序，但超导电性尚未被发现。
Recently, the Institute of Physics of the Chinese Academy of Sciences/Beijing National Research Center for Condensed Matter Physics and others have made progress in the research of two-dimensional van der Waals heavy fermion superconductors. Relying on the extremely low temperature, high hydrostatic pressure, and high-precision physical property measurement platform provided by the six-sided anvil high-pressure experimental station of the comprehensive extreme conditions experimental device, the team carried out high-voltage and low-temperature electrical transport measurements on CeSiI single crystals to construct a complete temperature-pressure phase diagram. The study found that the Kondo coherence temperatureT*(P)随加压先降低后升高，在约6 GPa达到最低值，呈现反常的“V”型演化规律，这与传统重费米子体系不同；反铁磁有序温度TN(P)随加压持续降低，在约6 GPa时完全消失；低温出现压力诱导的超导穹顶，其最高超导转变温度约240 mK，上临界场超过泡利顺磁极限的4至7倍。
The study further analyzed the electrical transport properties in the low-temperature normal state and found that the area adjacent to the superconducting dome has typical quantum critical characteristics such as linear resistivity and electron effective mass divergence. This indicates that this system may have an unconventional pairing mechanism driven by quantum critical antiferromagnetic fluctuations.
该研究首次在二维范德华重费米子体系CeSiI中实现了压力驱动的超导电性，并构建了包含近藤相干态、反铁磁有序、量子临界行为与非常规超导的完整相图。这不仅为探究二维极限下的重费米子超导提供了全新材料平台，并为未来借助机械剥离、应变调控及构建范德华异质器件等手段探索新型低维关联量子物态奠定了基础。
Relevant research results were published in "Nature-Physics" (Nature Physics）上。研究工作得到国家重点研发计划、国家自然科学基金、中国科学院相关项目及国家重大科技基础设施综合极端条件实验装置的支持。
Crystal structure and temperature-pressure phase diagram of CeSiI
Source: https://www.cas.cn/syky/202608/t20260828_5119229.shtml