Feng Haifeng, Liu Chen, Zhou Si, Gao Nan, Gao Qian, Zhuang Jincheng, Xu Xun, Hu Zhenpeng, Wang Jiaou, Chen Lan, Zhao Jijun, Dou Shi Xue, Du Yi
Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, Wollongong, New South Wales 2500, Australia.
BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, P.R. China.
Nano Lett. 2020 Apr 8;20(4):2537-2543. doi: 10.1021/acs.nanolett.9b05316. Epub 2020 Mar 27.
Two-dimensional (2D) materials with a Lieb lattice host exotic electronic band structures. Such a system does not exist in nature, and it is also difficult to obtain in the laboratory due to its structural instability. Here, we experimentally realized a 2D system composed of a tin overlayer on an aluminum substrate by molecular beam epitaxy. The specific arrangement of Sn atoms on the Al(100) surface, which benefits from favorable interface interactions, forms a stabilized buckled Lieb lattice. Theoretical calculations indicate a partially broken nodal line loop and a topologically nontrivial insulating state with a spin-orbital coupling effect in the band structure of this Lieb lattice. The electronic structure of this system is experimentally characterized by angle-resolved photoemission spectroscopy, in which the hybridized states between topmost Al atoms and Sn atoms are revealed. Our work provides an appealing method for constructing 2D quantum materials based on the Lieb lattice.
具有利布晶格的二维（2D）材料拥有奇异的电子能带结构。这样的体系在自然界中并不存在，并且由于其结构不稳定性，在实验室中也难以获得。在此，我们通过分子束外延实验实现了一个由铝衬底上的锡覆盖层组成的二维体系。得益于良好的界面相互作用，锡原子在Al(100)表面的特定排列形成了一种稳定的翘曲利布晶格。理论计算表明，在这种利布晶格的能带结构中存在部分断裂的节线环以及具有自旋轨道耦合效应的拓扑非平凡绝缘态。该体系的电子结构通过角分辨光电子能谱进行了实验表征，其中揭示了最顶层铝原子和锡原子之间的杂化态。我们的工作为基于利布晶格构建二维量子材料提供了一种有吸引力的方法。
