标题： 二维铁磁体 Fe$_3$GeTe$_2$中 Kondo 晶格行为的特征 显示英文标题

标题： Signatures of Kondo-lattice behavior in the two-dimensional ferromagnet Fe$_3$GeTe$_2$

摘要： 铁$_2$碲化锗$_3$是一种典型的范德华磁体，其磁相互作用的完整微观图景仍在讨论中。 在这里，我们使用 1.1 K 下的扫描隧道显微镜和谱学技术来描绘表面上的低能物理特性。 与之前的研究一致，我们观察到一个空间变化的法诺线型，这被归因于库恩多共振。 此外，我们在更大的能量法诺共振之上识别出一个宽度为$\approx$5 毫电子伏的小能隙。 我们认为这个能隙是相干库恩多晶格的特征，这种晶格被认为起源于一个强色散带和一个平带之间的杂化，这两个带都来源于晶格中铁原子的$d$电子。 在表面添加磁性吸附原子几乎不会影响基底的磁性特征，表明层内库恩多关联对磁性吸附物具有鲁棒性。 显示英文摘要

摘要： Fe$_2$GeTe$_3$ is a paradigmatic van der Waals magnet with the full microscopic picture of magnetic interactions still under debate. Here, we use scanning tunneling microscopy and spectroscopy at 1.1 K to map out the low-energy physics on the surface. In agreement with previous works, we observe a spatially varying Fano lineshape that has been ascribed to a Kondo resonance. In addition, we identify a small gap of $\approx$ 5 meV width on top of the larger-energy Fano resonance. We suggest that this gap is the signature of a coherent Kondo lattice that has been proposed to originate from hybridization of a strongly dispersing and a flat band both derived from $d$ electrons of the Fe atoms in the lattice. Adding magnetic adatoms on the surface hardly influences the magnetic signatures of the substrate, indicating the robustness of the intralayer Kondo correlations against magnetic adsorbates.