论文标题
氦离子显微镜，用于还原旋转轨道扭矩开关电流
Helium Ion Microscopy for Reduced Spin Orbit Torque Switching Currents
论文作者
论文摘要
旋转轨道扭矩驱动的开关是为记忆和无线通信设备操纵纳米级磁对象的一种有利方法。切换到另一种磁状态所需的临界电流取决于几何和所使用材料的内在特性，这些材料难以在本地控制。在这里，我们证明了聚焦的氦离子束照射如何以微观尺度调节CO薄膜的局部磁各向异性。使用异常霍尔效应的实时表征实时表征，在照射下显示了磁各向异性的数量级降低，并使用此效果显示了多层切换。结果是，在膜的预定区域可以实现旋转转换的电流密度，低至800 ka cm $^{ - 2} $，而无需光刻。在空间上改变临界电流的能力不仅对存储元素，而且对神经形态和概率计算具有影响。
Spin orbit torque driven switching is a favourable way to manipulate nanoscale magnetic objects for both memory and wireless communication devices. The critical current required to switch from one magnetic state to another depends on the geometry and the intrinsic properties of the materials used, which are difficult to control locally. Here we demonstrate how focused helium ion beam irradiation can modulate the local magnetic anisotropy of a Co thin film at the microscopic scale. Real-time in-situ characterisation using the anomalous Hall effect showed up to an order of magnitude reduction of the magnetic anisotropy under irradiation, and using this, multi-level switching is demonstrated. The result is that spin-switching current densities, down to 800 kA cm$^{-2}$, can be achieved on predetermined areas of the film, without the need for lithography. The ability to vary critical currents spatially has implications not only for storage elements, but also neuromorphic and probabilistic computing.
