Joseph Henry Laboratories of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2009 Oct 2;103(14):146401. doi: 10.1103/PhysRevLett.103.146401. Epub 2009 Sep 28.
We show that the strongly spin-orbit coupled materials Bi2Te3 and Sb2Te3 and their derivatives belong to the Z2 topological-insulator class. Using a combination of first-principles theoretical calculations and photoemission spectroscopy, we directly show that Bi2Te3 is a large spin-orbit-induced indirect bulk band gap (delta approximately 150 meV) semiconductor whose surface is characterized by a single topological spin-Dirac cone. The electronic structure of self-doped Sb2Te3 exhibits similar Z2 topological properties. We demonstrate that the dynamics of spin-Dirac fermions can be controlled through systematic Mn doping, making these materials classes potentially suitable for topological device applications.
我们证明了强自旋轨道耦合材料 Bi2Te3 和 Sb2Te3 及其衍生物属于 Z2 拓扑绝缘体类别。我们通过第一性原理理论计算和光电子能谱的结合，直接证明了 Bi2Te3 是一种大的自旋轨道诱导的间接体带隙（约 150meV）半导体，其表面具有单一的拓扑自旋狄拉克锥。自掺杂 Sb2Te3 的电子结构表现出类似的 Z2 拓扑性质。我们证明了通过系统的 Mn 掺杂可以控制自旋狄拉克费米子的动力学，这使得这些材料类别具有潜在的适用于拓扑器件应用的前景。
