EuTiO₃, a magnetic semiconductor with a simple band structure, is one of the ideal systems to control the anomalous Hall effect (AHE) by tuning the Fermi level. The electrons in the conduction bands of La-doped EuTiO₃ are subject to the spin-orbit interaction and Zeeman field from the spontaneous magnetization, which generates rich structures in the electron band such as Weyl nodes. This unique property makes EuTiO₃ a relatively simple multiband system with its Berry curvature being controlled by electron doping and magnetic field. We report a nonmonotonic magnetic field dependence of the anomalous Hall resistivity, which is ascribed to the change of electronic bands induced by the Zeeman splitting during the magnetization process. The anomalous Hall resistivity measurement in high-mobility films grown by gas source molecular beam epitaxy shows additional terms in the AHE during the magnetization process, which is not proportional to the magnetization. Our theoretical calculation indicates that the change of Zeeman field in the process of canting the magnetic moments causes the type II Weyl nodes in the conduction band to move, resulting in a peculiar magnetic field dependence of the AHE; this is revealed by the high-quality films with a long scattering lifetime of conduction electrons.

中文翻译：

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高迁移率EuTiO3薄膜中的多个Weyl节点产生异常的霍尔效应。

EuTiO ₃是一种具有简单能带结构的磁性半导体，是通过调节费米能级来控制异常霍尔效应（AHE）的理想系统之一。掺La的EuTiO ₃的导带中的电子会受到自旋磁化作用和自发磁化作用的塞曼场的影响，从而在电子带中产生丰富的结构，例如Weyl结。这种独特的性能使EuTiO ₃一个相对简单的多频带系统，其贝里曲率由电子掺杂和磁场控制。我们报告了异常霍尔电阻率的非单调磁场依赖性，这归因于在磁化过程中由塞曼分裂引起的电子带的变化。气源分子束外延生长的高迁移率薄膜中霍尔电阻率的异常测量表明，在磁化过程中，AHE中存在其他项，这与磁化强度不成正比。我们的理论计算表明，在倾斜磁矩的过程中，塞曼场的变化会导致导带中的II型Weyl节点移动，从而导致AHE的磁场依赖性变大。