Topological Character and Magnetism of the Dirac State in Mn-Doped Bi2Te3
Topological Character and Magnetism of the Dirac State in Mn-Doped Bi2Te3
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DOI：
10.1103/physrevlett.109.076801
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发表时间：
2012-08-16
影响因子：
8.6
通讯作者：
Chulkov, E. V.
中科院分区：
文献类型：
--
作者：
Henk, J.;Flieger, M.;Chulkov, E. V.
第一性原理和模型计算表明，拓扑绝缘体Bi2Te3的Dirac表面态在表面层掺杂适量Mn后仍然存在，但随着磁化方向的变化会失去其拓扑特征。色散在很大程度上取决于Mn磁化的方向：对于垂直磁化，在Dirac点打开16mev的间隙；对于平面内磁化，可以根据磁化方位打开或关闭一个微小的间隙。基态为铁磁性，临界温度为12k。研究结果为狄拉克表面态拓扑特征的磁控制及其对自旋相关输运性质的影响提供了一条途径。
First-principles and model calculations show that the Dirac surface state of the topological insulator Bi2Te3 survives upon moderate Mn doping of the surface layers but can lose its topological character as a function of magnetization direction. The dispersion depends considerably on the direction of the Mn magnetization: for perpendicular magnetization, a gap of 16 meV opens up at the Dirac point; for in-plane magnetization, a tiny gap can be opened or closed in dependence on the magnetization azimuth. The ground state is ferromagnetic, with a critical temperature of 12 K. The results provide a path towards a magnetic control of the topological character of the Dirac surface state and its consequences to spin-dependent transport properties.