论文标题
在二维su-schrieffer-heeger晶格中观察dirac锥体的观察
Observation of Gapped Dirac Cones in a Two-Dimensional Su-Schrieffer-Heeger Lattice
论文作者
论文摘要
二维矩形晶格中的Su-Schrieffer-Heeger（SSH）模型具有沿特定外围的拓扑边缘状态的无间隙或间隙的Dirac锥。尽管最近在光子/声学晶格和电路中实现了这样一个简单的模型，但仍缺乏其在凝结物质系统中的材料实现。在这里，我们通过角度分辨光发射光谱和理论计算来研究Ag（001）矩形SI晶格的原子和电子结构。我们证明了Si Lattice在Brillouin Zone Corners托管迪拉克锥体。我们的紧密结合分析表明，可以通过具有各向异性极化的2D SSH模型来描述狄拉克带。狄拉克锥的缝隙是由一个方向替代振幅的替代振幅驱动的，另一个方向交错的势能，并托有拓扑边缘状态。我们的结果建立了一个理想的平台，可以探索2D SSH模型的丰富物理特性。
The Su-Schrieffer-Heeger (SSH) model in a two-dimensional rectangular lattice features gapless or gapped Dirac cones with topological edge states along specific peripheries. While such a simple model has been recently realized in photonic/acoustic lattices and electric circuits, its material realization in condensed matter systems is still lacking. Here, we study the atomic and electronic structure of a rectangular Si lattice on Ag(001) by angle-resolved photoemission spectroscopy and theoretical calculations. We demonstrate that the Si lattice hosts gapped Dirac cones at the Brillouin zone corners. Our tight-binding analysis reveals that the Dirac bands can be described by a 2D SSH model with anisotropic polarizations. The gap of the Dirac cone is driven by alternative hopping amplitudes in one direction and staggered potential energies in the other one and hosts topological edge states. Our results establish an ideal platform to explore the rich physical properties of the 2D SSH model.
