论文标题
SNBI2TE4单晶的详细结构和拓扑分析
Detailed structural and topological analysis of SnBi2Te4 single crystal
论文作者
论文摘要
我们在此报告以单晶形式成功合成了拓扑材料SNBI2TE4。从粉末状样品和晶体薄片中获取的X射线衍射（XRD）图案中可以明显看出相纯度和单向生长。通过获取场发射扫描电子显微镜（FESEM）图像，也可以看到晶体形态。该晶体通过拉曼光谱和X射线光电子光谱（XPS）测量的方式彻底表征。 SNBI2TE4的拓扑特性已通过磁通型传输测量进行了探测。已经发现SNBI2TE4表现出较小但不饱和的磁耐药性（MR），高达12 t。在2 K时SNBI2TE4的低场磁导磁性（MC）可以通过Hikikami Larkin Nagaoka（HLN）的形式来很好地解释，这证实了存在的弱反态抗原分解（Wallocalcipation（Wallocaligation）的存在，以确认其存在。此外，通过使用密度功能理论（DFT），有或没有自旋轨道耦合（SOC）协议，通过第一原理计算（SOC）协议可以证明非平凡的拓扑特征。在包含SOC参数时，观察到大量电子带结构的显着变化，表示SNBI2TE4的拓扑特性。通过计算Z2不变性和（111）平面中的表面状态频谱，它的拓扑非平凡特征也得到了验证。
We report herein the successful synthesis of the topological material SnBi2Te4 in single-crystal form. Phase purity and unidirectional growth are evident from X-ray diffraction (XRD) patterns acquired from a powdered sample and a crystal flake. The crystalline morphology has also been visualized by acquiring a field-emission scanning electron microscope (FESEM) image. The crystal has been thoroughly characterized by means of Raman spectroscopy and X ray photoelectron spectroscopy (XPS) measurements. The topological properties of SnBi2Te4 have been probed through magneto-transport measurements. SnBi2Te4 has been found to exhibit a small but non-saturating magneto-resistance (MR) up to 12 T. The low-field magnetoconductivity (MC) of SnBi2Te4 at 2 K can be well explained through the Hikami Larkin Nagaoka (HLN) formalism, which confirms the presence of a weak anti-localization (WAL) effect in its crystal. Moreover, the non-trivial topological character has been evidenced through first-principles calculations using density functional theory (DFT), with and without spin-orbit coupling (SOC) protocols. A significant change in the bulk electronic band structure is observed upon the inclusion of SOC parameters, signifying the topological properties of SnBi2Te4. Its topological non-trivial character has also been verified through the calculation of Z2 invariants and the surface states spectrum in the (111) plane.
