论文标题
重金属 /铁磁异质结构中野外旋转轨道扭矩的调节
Modulation of field-like spin orbit torque in heavy metal / ferromagnet heterostructure
论文作者
论文摘要
最近的研究重新发现了野外旋转轨道扭矩（SOT）在纳秒时间尺度SOT动力学中的关键作用。但是，尚无一种控制其相对幅度的有效方法。在这里，我们通过调整界面自旋积累来实验地调节W/COFEB/MGO Trilayers中的场状SOT。通过执行自旋大厅的磁化测量测量，我们发现具有增强自旋脱位的COFEB，是由较大的层厚度或适当退火产生的，可以明显地增强自旋吸收并增强界面自旋混合电导电导率G_R。尽管阻尼样扭矩效率随G_R的增加而增加，但磁场状的扭矩效率却随之降低。结果表明，较高的界面自旋透明度降低了界面自旋积累，这在很大程度上导致了场状扭矩。我们的工作显示了一条新的途径，以进一步改善基于SOT的磁性设备的性能。
Recent studies rediscovered the crucial role of field-like spin orbit torque (SOT) in nanosecond-timescale SOT dynamics. However, there is not yet an effective way to control its relative amplitude. Here, we experimentally modulate the field-like SOT in W/CoFeB/MgO trilayers through tuning the interfacial spin accumulation. By performing spin Hall magnetoresistance measurement, we find that the CoFeB with enhanced spin dephasing, either generated from larger layer thickness or from proper annealing, can distinctly boost the spin absorption and enhance the interfacial spin mixing conductance G_r. While the damping-like torque efficiency increases with G_r, the field-like torque efficiency turns out to decrease with it. The results suggest that the interfacial spin accumulation, which largely contributes to a field-like torque, is reduced by higher interfacial spin transparency. Our work shows a new path to further improve the performance of SOT-based magnetic devices.
