Kagome magnet has been found to be a fertile ground for the search of exotic quantum states in condensed matter. Arising from the unusual geometry, the quantum interactions in the kagome lattice give rise to various quantum states, including the Chern-gapped Dirac fermion, Weyl fermion, flat band and van Hove singularity. Here we review recent advances in the study of the R166 kagome magnet (RT₆E₆, R = rare earths; T = transition metals; and E = Sn, Ge, etc) whose crystal structure highlights the transition-metal-based kagome lattice and rare-earth sublattice. Compared with other kagome magnets, the R166 family owns the particularly strong interplays between the d electrons on the kagome site and the localized f electrons on the rare-earth site. In the form of spin-orbital coupling, exchange interaction and many-body effect, the quantum interactions play an essential role in the Berry curvature in both the reciprocal and real spaces of R166 family. We discuss the spectroscopic and transport visualization of the topological electrons hosted in the Mn kagome layer of RMn₆Sn₆ and the various topological effects due to the quantum interactions, including the Chern-gap opening, the exchange-biased effect, the topological Hall effect and the emergent inductance. We hope this work serves as a guide for future explorations of quantum magnets.

中文翻译：

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拓扑 R166 kagome 磁体中的量子相互作用


人们发现 Kagome 磁铁是寻找凝聚态物质中奇异量子态的沃土。由于不寻常的几何形状，戈薇晶格中的量子相互作用产生了各种量子态，包括陈能隙狄拉克费米子、韦尔费米子、平带和范霍夫奇点。这里我们回顾一下R166戈薇磁体的研究进展（RT ₆ E ₆ ，R=稀土；T=过渡金属；E=Sn、Ge等）其晶体结构突出了过渡金属基戈戈米晶格和稀土亚晶格。与其他戈薇磁铁相比，R166系列在戈薇位点上的d电子与稀土位点上的局域f电子之间具有特别强的相互作用。量子相互作用以自旋轨道耦合、交换相互作用和多体效应的形式，在 R166 族的倒易空间和实空间中的贝里曲率中发挥着重要作用。我们讨论了 RMn ₆ Sn ₆ 的 Mn kagome 层中托管的拓扑电子的光谱和输运可视化，以及由于量子相互作用（包括陈能隙）而产生的各种拓扑效应开路、交换偏置效应、拓扑霍尔效应和涌现电感。我们希望这项工作能够为未来量子磁体的探索提供指导。