论文标题
部分放松的200 nm hgte膜中的弱抗钙化
Weak antilocalization in partially relaxed 200-nm HgTe films
论文作者
论文摘要
通过实验研究了由200 nm HGTE膜中弱抗钙作用（WAL）效应引起的异常磁磁性。该膜是一种高质量的3D拓扑绝缘子，其表面状态的空间分离要比先前研究的较薄的HGTE结构更强。然而，与该膜相反，所研究的系统的特征是部分应变减少，导致散装能量差距几乎为零。已经表明，在费米级的所有位置，系统都表现出叠加在经典抛物线磁力胜地上的象牙电导率校正。由于载体的迁移率很高，因此使用弹道WAL理论对获得的结果进行了分析。在大容量能量间隙附近的费米水平位置上发现了最大的壁电导率校正振幅，这表明在这些条件下表面载体完全解耦。当散装电子或孔的密度增加时，WAL振幅单调降低，这是由于表面和散装载体之间的耦合增加而导致的。
The anomalous magnetoresistance caused by the weak antilocalization (WAL) effects in 200-nm HgTe films is experimentally studied. The film is a high quality 3D topological insulator with much stronger spatial separation of surface states than in previously studied thinner HgTe structures. However, in contrast to that films, the system under study is characterized by a reduced partial strain resulting in an almost zero bulk energy gap. It has been shown that at all positions of the Fermi level the system exhibits a WAL conductivity correction superimposed on classical parabolic magnetoresistance. Since high mobility of carriers, the analysis of the obtained results was performed using a ballistic WAL theory. The maximum of the WAL conductivity correction amplitude was found at a Fermi level position near the bulk energy gap indicating to full decoupling of the surface carriers in these conditions. The WAL amplitude monotonously decreases when the density of either bulk electrons or holes increases that results from the increasing coupling between surface and bulk carriers.
