Novel 2D Materials: Functionalized Stanene and Bismuthene Honeycomb Lattices

该项目旨在实现和调整蜂窝晶格的拓扑相，即石墨烯类似物，由高Z原子构建。我们专注于锡和铋原子的蜂窝（锡烯，铋烯）。这些理论上被描述为宽隙量子自旋霍尔（QSH）系统，适用于室温应用。为了解决实际实现问题，我们已经确定SiC（0001）作为合适的衬底。我们的外延实验已经成功地生产锡和铋蜂窝层，其特征在于扫描隧道显微镜（STM）。该项目将探讨功能化对电子和拓扑性质的影响。这包括蜂窝层下方的缓冲层，以及表面官能化，例如，金属或卤素原子。有趣的是，用氢原子或磁性杂质装饰有望产生量子反常霍尔（QAH）效应。的拓扑性质将探讨通过扫描隧道光谱（STS）的1D边缘通道。用角分辨光电子能谱（ARPES）分析了能带结构。因此，我们的外延技术提供了一种新型的QSH材料，可在SPP 1666优先计划中进行交换。它将受益于与许多其他项目的密切合作，从密度泛函理论到基于同步加速器的方法，光谱技术和解决传输特性的项目。

This project is aimed at realizing and tuning the topological phases of honeycomb lattices, i.e. of Graphene analogs, built from high-Z atoms. We focus on honeycombs of Sn and Bi atoms (Stanene, Bismuthene). These are theoretically described as wide-gap Quantum Spin Hall (QSH) systems, suitable for room temperature applications. Addressing the practical realization, we have identified SiC(0001) as a suitable substrate. Our epitaxial experiments have already succeeded in producing Sn and Bi honeycomb layers, characterized by scanning tunneling microscopy (STM). The project will explore the effect of functionalization on the electronic and topological properties. This includes buffer layers below the honeycomb layer, as well as surface functionalization with, e.g., metal or halogen atoms. Intriguingly, decoration with hydrogen atoms or magnetic impurities is expected to create the Quantum Anomalous Hall (QAH) effect. The topological properties will be probed by scanning tunneling spectroscopy (STS) of the 1D edge channels. The band structure is accessed by angle-resolved photoemission (ARPES). Our epitaxy technology thus provides access to a novel class of QSH materials, available for exchange in the SPP 1666 Priority Program. It will profit from close collaboration with many other projects, reaching from density functional theory to synchrotron-based methods, optical spectroscopy techniques, and projects addressing the transport properties.