Experimental Realization of a Three-Dimensional Topological Insulator, Bi2Te3
Experimental Realization of a Three-Dimensional Topological Insulator, Bi2Te3
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DOI：
10.1126/science.1173034
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发表时间：
2009-07-10
期刊：
影响因子：
56.9
通讯作者：
Shen, Z. -X.
中科院分区：
文献类型：
--
作者：
Chen, Y. L.;Analytis, J. G.;Shen, Z. -X.
三维拓扑绝缘体是一种新的量子物质状态，具有体能隙，表面有奇数个相对论狄拉克费米子。用角分辨光电子能谱研究了Bi2Te3的表面态，证明表面态是由一个非简并的Dirac锥组成的。此外，通过适当的空穴掺杂，费米能级可以被调谐到只与表面态相交，这表明体态有一个完整的能隙。我们的结果表明，Bi2Te3是一个简单的三维拓扑绝缘体模型系统，表面只有一个狄拉克锥体。Bi2Te3的大体积能隙也预示着高温自旋电子学应用的巨大潜力。
Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi2Te3 with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi2Te3 is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi2Te3 also points to promising potential for high-temperature spintronics applications.