Berry phase is a powerful concept that unravels the nontrivial role of topology in phenomena observed in chiral magnetic materials and structures. A celebrated example is the anomalous Hall effect (AHE) driven by the nonvanishing Berry phase in momentum space. As the AHE is dependent on details of the band structure near the Fermi edge, the Berry phase and AHE can be altered in thin films whose chemical potential is tunable by dimensionality and disorder. Here, we demonstrate how Berry phase in ultrathin ${\mathrm{SrRuO}}_3$ films provides a comprehensive explanation for the nontrivial Hall response which is conventionally attributed to the topological Hall effect (THE). Particularly, the Berry phase contribution to this effect can be altered, enhanced, and even change signs in response to the number of layers, temperature, and importantly, disorder. By comparing the effects of disorder theoretically on a skyrmion model and a spin-orbit coupled model, we show that disorder suppresses the THE while it can enhance the AHE. The experiments on more disordered samples confirm this interpretation, and proposed multichannel analysis judiciously explains the observed THE-like feature.

中文翻译：

---

超薄SrRuO3薄膜中的浆果相操纵

贝里相是一个有力的概念，它揭示了拓扑结构在手性磁性材料和结构中观察到的现象中的重要作用。一个著名的例子是由动量空间中不变的Berry相驱动的异常霍尔效应（AHE）。由于AHE取决于费米边缘附近能带结构的细节，因此可以改变其化学势可通过尺寸和无序调节的薄膜中的Berry相和AHE。在这里，我们演示了Berry相如何超薄${锶}_3$影片为不平凡的霍尔响应提供了全面的解释，该响应通常归因于拓扑霍尔效应（THE）。特别地，响应于层数，温度以及重要的是无序，可以改变，增强甚至改变信号的浆果相贡献。通过理论上比较无序对Skyrmion模型和自旋轨道耦合模型的影响，我们表明，无序抑制了THE，同时可以增强AHE。在更多无序样本上进行的实验证实了这种解释，并提出的多通道分析明智地解释了观察到的类似THE的特征。