标题： Ni4W中的巨自旋霍尔效应及其多方向自旋分量 显示英文标题

标题： Giant spin Hall effect with multi-directional spin components in Ni4W

摘要： 自旋-轨道矩（SOT）可以用来高效地操控磁性材料的磁态，这是存储和逻辑应用中的关键要素。 由于对称性约束，对于传统的SOT材料如重金属和拓扑材料，只有面内自旋可以从底层的SOT层注入到铁磁体中。 通过使用低对称性的材料或其他打破对称性的方法，已经展示了具有面外极化的非常规自旋电流，并实现了垂直磁化方向的无场确定性切换。 尽管取得了这些进展，这些材料的SOT效率通常仍然较低。 在这里，我们报告了在室温下溅射制备的Ni4W/CoFeB异质结构中，通过二次谐波霍尔测量评估得到的0.85的巨大SOT效率。 此外，由于Ni4W的低晶体对称性，观察到了非常规的面外和Dresselhaus-like自旋分量。 宏观自旋模拟表明，我们的自旋霍尔张量可将磁化切换效率提高一个数量级，从而拓宽了利用低对称性材料实现能量高效的自旋电子器件的路径。 显示英文摘要

摘要： Spin-orbit torque (SOT) can be used to efficiently manipulate the magnetic state of magnetic materials, which is an essential element for memory and logic applications. Due to symmetry constraints, only in-plane spins can be injected into the ferromagnet from the underlying SOT layer for conventional SOT materials such as heavy metals and topological materials. Through the use of materials with low symmetries, or other symmetry breaking approaches, unconventional spin currents with out-of-plane polarization has been demonstrated and enabled field-free deterministic switching of perpendicular magnetization. Despite this progress, the SOT efficiency of these materials has typically remained low. Here, we report a giant SOT efficiency of 0.85 in sputtered Ni4W/CoFeB heterostructure at room temperature, as evaluated by second harmonic Hall measurements. In addition, due to the low crystal symmetry of Ni4W, unconventional out-of-plane and Dresselhaus-like spin components were observed. Macro-spin simulation suggests our spin Hall tensor to provide about an order of magnitude improvement in the magnetization switching efficiency, thus broadening the path towards energy efficient spintronic devices using low-symmetry materials.