The spin–orbit torque (SOT) that arises from materials with large spin–orbit coupling promises a path for ultralow power and fast magnetic-based storage and computational devices. We investigated the SOT from magnetron-sputtered Bi_xSe_(1–x) thin films in Bi_xSe_(1–x)/Co₂₀Fe₆₀B₂₀ heterostructures by using d.c. planar Hall and spin-torque ferromagnetic resonance (ST-FMR) methods. Remarkably, the spin torque efficiency (θ_S) was determined to be as large as 18.62 ± 0.13 and 8.67 ± 1.08 using the d.c. planar Hall and ST-FMR methods, respectively. Moreover, switching of the perpendicular CoFeB multilayers using the SOT from the Bi_xSe_(1–x) was observed at room temperature with a low critical magnetization switching current density of 4.3 × 10⁵ A cm^–2. Quantum transport simulations using a realistic sp³ tight-binding model suggests that the high SOT in sputtered Bi_xSe_(1–x) is due to the quantum confinement effect with a charge-to-spin conversion efficiency that enhances with reduced size and dimensionality. The demonstrated θ_S, ease of growth of the films on a silicon substrate and successful growth and switching of perpendicular CoFeB multilayers on Bi_xSe_(1–x) films provide an avenue for the use of Bi_xSe_(1–x) as a spin density generator in SOT-based memory and logic devices.

由具有大自旋轨道耦合的材料产生的自旋轨道扭矩（SOT）有望为超低功耗和基于磁性的快速存储和计算设备铺平道路。我们研究了从磁控管溅射碧SOT _X硒_{（1- X）}薄膜中的Bi _X硒_{（1- X）} /钴₂₀的Fe _60个乙_20个通过使用直流平面霍尔和自旋扭矩铁磁共振（ST-FMR异质结构） 方法。值得注意的是，自旋扭矩效率（θ_小号分别使用直流平面霍尔法和ST-FMR方法确定）分别高达18.62±0.13和8.67±1.08。此外，在室温下观察到使用Bi _x Se _{（1– x）中}的SOT转换垂直CoFeB多层膜的临界磁化强度较低，其开关电流密度为4.3×10 ⁵  A cm ^–2。使用逼真的sp ³紧束缚模型进行的量子传输模拟表明，溅射Bi _x Se _{（1- x）中的}SOT较高。这是由于量子约束效应具有电荷自旋转换效率，随着尺寸和尺寸的减小而增强。所表现出的θ_小号，易于在硅衬底和成功的增长对薄膜的生长和垂直的CoFeB多层膜的上毕切换_X硒_{（1- X）}膜提供使用Bi的途径_X硒_{（1- X）}作为基于SOT的存储器和逻辑设备中的自旋密度生成器。