Magnetism in two-dimensional (2D) van der Waals (vdW) materials has lately attracted considerable attention from the point of view of both fundamental science and device applications. Obviously, establishing a detailed and solid understanding of their magnetism is the key first step toward various applications. Although Fe₃GeTe₂ is a representative ferromagnetic (FM) metal in this family, many aspects of its magnetic and electronic behaviors still remain elusive. Here, we report our new finding that Fe₃GeTe₂ is a special type of correlated metal known as “Hund metal”. Furthermore, we demonstrate that Hund metallicity in this material is quite unique by exhibiting remarkable site dependence of Hund correlation strength, hereby dubbed “site-differentiated Hund metal”. Within this new picture, many of the previous experiments can be clearly understood, including the ones that were seemingly contradictory to one another.

从基础科学和设备应用的角度来看，二维 (2D) 范德华 (vdW) 材料中的磁性最近引起了相当大的关注。显然，对它们的磁性建立详细而扎实的了解是迈向各种应用的关键的第一步。尽管 Fe ₃ GeTe ₂是该家族中具有代表性的铁磁 (FM) 金属，但其磁性和电子行为的许多方面仍然难以捉摸。在这里，我们报告了我们的新发现，即 Fe ₃ GeTe ₂是一种特殊类型的相关金属，称为“Hund 金属”。此外，我们通过展示 Hund 相关强度的显着位置依赖性，证明了这种材料中的 Hund 金属丰度非常独特，因此被称为“位点分化的 Hund 金属”。在这幅新图景中，可以清晰地理解之前的许多实验，包括那些看似相互矛盾的实验。