Atomic-scale spin entity in a two-dimensional topological insulator lays the foundation to manufacture magnetic topological materials with single atomic thickness. Here, we have successfully fabricated Fe monomer, dimer and trimer doped in the monolayer stanene/Cu(111) through a low-temperature growth and systematically investigated Kondo effect by combining scanning tunneling microscopy/spectroscopy (STM/STS) with density functional theory (DFT) and numerical renormalization group (NRG) method. Given high spatial and energy resolution, tunneling conductance (dI/dU) spectra have resolved zero-bias Kondo resonance and resultant magnetic-field-dependent Zeeman splitting, yielding an effective spin S_eff = 3/2 with an easy-plane magnetic anisotropy on the self-assembled Fe atomic dopants. Reduced Kondo temperature along with attenuated Kondo intensity from Fe monomer to trimer have been further identified as a manifestation of Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between Sn-separated Fe atoms. Such magnetic Fe atom assembly in turn constitutes important cornerstones for tailoring topological band structures and developing magnetic phase transition in the single-atom-layer stanene.

二维拓扑绝缘体中的原子尺度自旋实体为制造单原子厚度的磁性拓扑材料奠定了基础。在这里，我们通过低温生长成功地制备了单层锡烯/Cu（111）中掺杂的Fe单体、二聚体和三聚体，并通过将扫描隧道显微镜/光谱学（STM/STS）与密度泛函理论相结合系统地研究了近藤效应（ DFT）和数值重正化群（NRG）方法。考虑到高空间和能量分辨率，隧道电导 (d I /d U ) 谱已经解决了零偏置近藤共振和由此产生的磁场相关的塞曼分裂，产生有效自旋S _eff  = 3/2 和易平面磁自组装 Fe 原子掺杂剂的各向异性。近藤温度降低以及从 Fe 单体到三聚体的近藤强度减弱已被进一步确定为 Sn 分离的 Fe 原子之间 Ruderman-Kittel-Kasuya-Yosida (RKKY) 相互作用的表现。这种磁性铁原子组装反过来又构成了调整拓扑能带结构和发展单原子层锡烯磁性相变的重要基石。