论文标题
在磁性绝缘体/拓扑绝缘器异质结构中观察非线性平面厅效应
Observation of nonlinear planar Hall effect in magnetic insulator/topological insulator heterostructures
论文作者
论文摘要
将拓扑绝缘子（TIS）与磁绝缘子（MIS）的接口进行了广泛用于研究拓扑表面状态与磁性之间的相互作用。先前的运输研究通常将抑制弱抗钙化或异常霍尔效应的外观抑制为对TIS施加的磁接近效应（MPE）的特征。在这里，我们报告了在Mi Thulium和Yttrium Iron Garnet（Tmig和Yig）底物上生长的BI2SE3膜中非线性平面厅效应（NPHE）的观察，该层比非磁性GADOLIUM GALDOLIUM GALDOLIUM GALLIUM GARNET（GGG）sisubstretate（GGG）底物生长的BI2SE3级。 TMIG/BI2SE3中的非线性霍尔电阻线性取决于外部磁场，而YIG/BI2SE3中的非线性霍尔电阻在零场周围表现出额外的磁滞回路。发现NPHE的幅度随载体密度呈相反。我们推测观察到的NPHE与Ti表面状态的MPE诱导的交换间隙开口和平面外旋转纹理有关，这可以用作MI/TI异质结构中MPE的替代传输特征。
Interfacing topological insulators (TIs) with magnetic insulators (MIs) has been widely used to study the interaction between topological surface states and magnetism. Previous transport studies typically interpret the suppression of weak antilocalization or appearance of the anomalous Hall effect as signatures of magnetic proximity effect (MPE) imposed to TIs. Here, we report the observation of nonlinear planar Hall effect (NPHE) in Bi2Se3 films grown on MI thulium and yttrium iron garnet (TmIG and YIG) substrates, which is an order of magnitude larger than that in Bi2Se3 grown on nonmagnetic gadolinium gallium garnet (GGG) substrate. The nonlinear Hall resistance in TmIG/Bi2Se3 depends linearly on the external magnetic field, while that in YIG/Bi2Se3 exhibits an extra hysteresis loop around zero field. The magnitude of the NPHE is found to scale inversely with carrier density. We speculate the observed NPHE is related to the MPE-induced exchange gap opening and out-of-plane spin textures in the TI surface states, which may be used as an alternative transport signature of the MPE in MI/TI heterostructures.
