Weak localization properties of the doped Z2 topological insulator
Weak localization properties of the doped Z2 topological insulator
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DOI：
10.1103/physrevb.80.085119
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发表时间：
2009-08-01
影响因子：
3.7
通讯作者：
Nomura, Kentaro
中科院分区：
文献类型：
--
作者：
Imura, Ken-Ichiro;Kuramoto, Yoshio;Nomura, Kentaro
利用弱局域化理论研究了掺杂Z（2）拓扑绝缘体的局域化性质。以石墨烯的无序Kane-Mele模型为原型，分析了拓扑质量项、谷间散射和Rashba自旋-轨道相互作用的影响.在K点和K-1点之间不存在谷间散射的情况下，石墨烯反定域化的已知趋势自然地被放置为凯恩-梅勒模型的无质量极限。后者被证明有一个单一的行为，即使在磁场的情况下，由于拓扑质量项。当引入谷间散射时，拓扑质量项使系统处于酉类，而当A和B子晶格不等价时出现的普通质量项使系统变为弱局域化。在K-K散射存在下的Rashba自旋-轨道相互作用驱动系统弱反定域化，与理想石墨烯情况形成鲜明对比。
Localization properties of the doped Z(2) topological insulator are studied by weak localization theory. The disordered Kane-Mele model for graphene is taken as a prototype and analyzed with attention to effects of the topological mass term, intervalley scattering, and the Rashba spin-orbit interaction. The known tendency of graphene to antilocalize in the absence of intervalley scattering between K and K-' points is naturally placed as the massless limit of the Kane-Mele model. The latter is shown to have a unitary behavior even in the absence of magnetic field due to the topological mass term. When intervalley scattering is introduced, the topological mass term leaves the system in the unitary class, whereas the ordinary mass term, which appears if A and B sublattices are inequivalent, turns the system to weak localization. The Rashba spin-orbit interaction in the presence of K-K-' scattering drives the system to weak antilocalization in sharp contrast to the ideal graphene case.