Magnetic Weyl semimetals with spontaneously broken time-reversal symmetry exhibit a large intrinsic anomalous Hall effect originating from the Berry curvature. To employ this large Hall current for room temperature topo-spintronics applications, it is necessary to fabricate these materials as thin or ultrathin films. Here, we experimentally demonstrate that Weyl semimetal Co₂MnGa thin films (20–50 nm) show a large anomalous Hall angle ~11.4% at low temperature and ~9.7% at room temperature, which can be ascribed to the non-trivial topology of the band structure with large intrinsic Berry curvature. However, the anomalous Hall angle decreases significantly with thicknesses below 20 nm, which band structure calculations confirm is due to the reduction of the majority spin contribution to the Berry curvature. Our results suggest that Co₂MnGa is an excellent material to realize room temperature topo-spintronics applications; however, the significant thickness dependence of the Berry curvature has important implications for thin-film device design.

具有自发性的时间反转对称性的磁性Weyl半金属表现出源自Berry曲率的大固有异常霍尔效应。为了将这种大霍尔电流用于室温拓扑自旋电子应用，有必要将这些材料制成薄膜或超薄膜。在这里，我们通过实验证明了Weyl半金属Co ₂MnGa薄膜（20–50 nm）在低温下显示出大的异常霍尔角，在室温下为〜11.4％，在室温下显示为〜9.7％，这可以归因于具有大固有Berry曲率的能带结构的非平凡拓扑。但是，异常霍尔角在厚度小于20 nm时会显着减小，该能带结构计算证实是由于多数自旋对Berry曲率的贡献减小。我们的结果表明，Co ₂ MnGa是实现室温陀螺自旋电子学应用的出色材料。然而，浆果曲率对厚度的显着依赖性对薄膜器件设计具有重要意义。