磁性掺杂拓扑绝缘体的表面磁性研究

Topological insulator is a new special quantum system which gains intensive interest in recent years for its revolutionary application potential in electronics, spintronics and quantun computation. The key to realize the application of topological insulator is a proper manipulation of its topological surface state. One of the most important aspects is the realization, detection and manipulation of the magnetism of surface states which is crucial for its application in spintronics. Since the surface magnetism only exists at the surface region, an extremely surface sensitive technique is highly needed to investigate the magnetism of surface states. Up to now, the experimental study on the surface magnetism of topological insulators is still in the beginning stage. In this porposal, we plan to grow topological insulator and realize the magntic doping by molecular beam epitaxy in ultrahigh vacuum system and investigate and manipulate its surface magntism with spin polarized scannning tunneling microscopy on the atomic scale. The study is to build up basic knowledge of the surface magentism of topological insulator for its future application in new spintronic devices.

拓扑绝缘体是近年来在国际上引起高度关注的一种特殊的新量子体系，在电子学、自旋电子学和量子计算等方面具有革命性的应用前景。实现拓扑绝缘体的应用的关键是对拓扑绝缘体的表面态性质进行调控，其中非常重要的一个方面是如何实现、探测并且调控拓扑绝缘体的表面态的磁性，这是拓扑绝缘体实现自旋电子学器件应用的基础。由于拓扑绝缘体的表面磁性仅在表面存在，因此需要及其灵敏的表面磁性探测手段。目前，这一方面的实验研究还处在刚刚开始的阶段。本项目计划在超高真空下实现拓扑绝缘体的生长以及磁性掺杂,并利用原子级分辨的表面自旋敏感探测手段-自旋极化扫描隧道显微镜-实现对其表面磁性的原位表征以及表面自旋的调控，为发展新型自旋电子学器件提供基础。

拓扑绝缘体由于其在电子学、自旋电子学和量子计算等方面的应用前景而成为近年来研究的热点。本项目着重研究了如何在超高真空环境下在拓扑绝缘体表面实现磁性掺杂、磁性薄膜生长，并利用自旋极化扫描隧道显微镜对磁性进行控制和表征，研究了磁性薄膜在拓扑绝缘体表面的磁畴形成情况，特别是对磁性分子在拓扑绝缘体表面的磁性行为做了深入的研究，共发表受本项目资助论文10篇。