拓扑表面态新奇自旋构形的自旋极化扫描隧道谱研究

项目名称： 拓扑表面态新奇自旋构形的自旋极化扫描隧道谱研究

项目编号： No.11474112

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 付英双

作者单位： 华中科技大学

项目金额： 100万元

中文摘要： 拓扑绝缘体表面态具有独特的自旋特性，是许多新奇拓扑量子物理现象的基础。目前对拓扑表面态自旋的研究主要借助于自旋和角度分辨的光电子能谱在动量空间展开，但是在实空间的研究尚属空白。在本项目中，我们将利用自旋极化扫描隧道显微镜这种对自旋灵敏的实空间表征工具，研究拓扑表面态在特定外界作用下在实空间预期出现的新奇自旋量子现象。这包括系统研究拓扑绝缘体Bi2Se3中的朗道波函数在杂质电势调控下产生的新奇自旋构形，以揭示拓扑表面态朗道波函数的自旋特性；探测Cr掺杂的磁性拓扑绝缘体Sb2Te3表面态中的磁畴结构和手性边界态，并澄清其中的磁性相互作用机制。该项目的实施将一方面丰富我们对拓扑表面态自旋特性的理解，为实现更加新奇的拓扑物理现象奠定基础，另一方面将为拓扑绝缘体在自旋电子学中的应用开辟新的平台。

中文关键词： 拓扑表面态；自旋极化扫描隧道显微镜；朗道波函数；电子结构；自旋构形

英文摘要： The surface state of topological insulators has unique spin characters, which is the basis for many novel topological quantum phenomena.To date, the studies on the spin properties of topological surface state have been mainly focused on its momentum space with spin and angle resolved photo emission spectroscopy. And its study in real space is still lacking. In this project, we will use spin-polarized scanning tunneling microscopy, which is a probe that is spin sensitive in real space, to investigate the novel quantum spin phenomena of topological surface state, which are expected to emerge in real space under certain external perturbations. We will systematically investigate the novel spin textures that are generated by the influence of an impurity potential on the Landau wave functions of topological surface state in Bi2Se3.The study could unravel the spin character in the Landau wave function of topological surface state. We will also investigate the magnetic domain structure and chiral edge modes that are existing in Cr doped magnetic topological insulator Sb2Te3, and clarify the underlying mechanism that mediates the magnetic interaction. The execution of this project will on one hand enrich our understanding of the spin properties of topological surface state, set a foundation for exploring yet more exotic topological phenomena, and on the other hand open a new platform for the application of topological insulators in spin-based electronics.

英文关键词： topological surface state;SPSTM;Landau wave function;electronic structure;spin texture