Song Boqin, Xie Yuyang, Li Wei-Jian, Liu Hui, Chen Jing, Tian Shangjie, Zhang Xing, Wang Qinghong, Li Xintong, Lei Hechang, Zhang Qinghua, Guo Jian-Gang, Zhao Lin, Yu Shun-Li, Zhou Xingjiang, Chen Xiaolong, Ying Tianping
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2025 Jul 1;16(1):5643. doi: 10.1038/s41467-025-60785-3.
The Kondo lattice, describing a grid of the local magnetic moments coupling to itinerant electrons, is a fertile ground of strongly correlated states in condensed matter physics. While the Kagome lattice has long been predicted to host Kondo physics with exotic magnetism and nontrivial topology, no experimental realization has been achieved to the best of our knowledge. Here, we report the discovery of CsCrSb, a van der Waals-like Kagome Kondo lattice featuring extremely flat, isolated bands at the Fermi level that composed entirely of Cr-3d electrons. We observe heavy fermions with the effective mass over 100 times greater than those of its vanadium counterpart. We also observe Kondo insulating behavior in an ultra-low carrier density of 10cm and dimensionality-induced Kondo breakdown. Counterintuitively, mechanical exfoliation of the frustrated bulk reveals hidden A-type antiferromagnetism with even-odd layer-dependent anomalous Hall effect. The realization of Kondo physics in Kagome lattice opens avenues for exploring diverse quantum criticalities in a strongly-correlated frustrated system.
近藤晶格描述了与巡游电子耦合的局域磁矩网格，是凝聚态物理中强关联态的一个丰富来源。虽然长期以来人们一直预测 Kagome 晶格会呈现具有奇异磁性和非平凡拓扑结构的近藤物理，但据我们所知，尚未有实验实现。在此，我们报告发现了 CsCrSb，一种类似范德华的 Kagome 近藤晶格，其在费米能级处具有极其平坦、孤立的能带，这些能带完全由 Cr - 3d 电子组成。我们观察到有效质量比钒对应物大 100 倍以上的重费米子。我们还在超低载流子密度 10cm 下观察到近藤绝缘行为以及维度诱导的近藤击穿。与直觉相反，受挫体块的机械剥离揭示了隐藏的 A 型反铁磁性以及与奇偶层相关的反常霍尔效应。Kagome 晶格中近藤物理的实现为探索强关联受挫系统中的各种量子临界性开辟了道路。
