二维电子化合物上由浮动电子覆盖的拓扑费米弧表面态
Topological Fermi-arc surface state covered by floating electrons on a two-dimensional electride
AI总结：
本研究通过ARPES和STM实验，首次在铁磁电子化合物[Gd₂C]²⁺·2e⁻中观测到外尔锥与费米弧拓扑表面态，且该态位于顶层浮动量子电子液体下方形成双层表面态，验证了其非平庸拓扑性并实现新型表面异质结。
摘要：
二维电子化合物因阳离子原子层与阴离子电子层之间的有趣的相互作用，可获得拓扑非平庸相。然而，拓扑表面态的实验证据仍有待验证。本文通过角分辨光电子能谱（ARPES）和扫描隧道显微镜（STM），我们探测了铁磁电子化合物$[Gd_{2}C]^{2+}\u00b7}2e^{-}$的磁性外尔态。特别地，依赖光子能量的ARPES测量证实了外尔锥和费米弧态的存在，这与理论能带结构计算一致。值得注意的是，STM测量显示费米弧态存在于顶层Gd层上的浮动量子电子液体下方，在异质结中形成了双层堆叠的表面态。因此，我们的工作不仅揭示了$[Gd_{2}C]^{2+}\u00b7}2e^{-}$电子化合物的非平庸拓扑性质，还实现了一种能够承载不同于体相现象的表面异质结。
英文摘要：
Two-dimensional electrides can acquire topologically non-trivial phases due to intriguing interplay between the cationic atomic layers and anionic electron layers. However, experimental evidence of topological surface states has yet to be verified. Here, via angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM), we probe the magnetic Weyl states of the ferromagnetic electride $[Gd_{2}$C]^{2+}\cdot2e^{-}$. In particular, the presence of Weyl cones and Fermi-arc states is demonstrated through photon energy-dependent ARPES measurements, agreeing with theoretical band structure calculations. Notably, the STM measurements reveal that the Fermi-arc states exist underneath a floating quantum electron liquid on the top Gd layer, forming double-stacked surface states in a heterostructure. Our work thus not only unveils the non-trivial topology of the $[Gd_{2}$C]^{2+}\cdot2e^{-}$ electride but also realizes a surface heterostructure that can host phenomena distinct from the bulk.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
