论文标题
由于电流限制在纳米线中，Skyrmion自旋传输扭矩
Skyrmion spin transfer torque due to current confined in a nanowire
论文作者
论文摘要
在这项工作中，我们计算出存在Skyrmion时与金属纳米线接触的Ferromagnet中存在的扭矩场。如果纳米线足够窄，则电流由单个传导带携带。在此策略中，经典扭矩模型分解了，我们表明，由自旋传输扭矩驱动的天际速度朝着与经典模型预测的不同方向移动。但是，在单个带状态下以一定速度移动Skyrmion所需的充电电流类似于经典的扭矩模型，在许多传导带中隐式地假定了电流传输。由于单带的完美极化，因此单个频带态度更有效地产生了旋转电流，但从旋转电流产生扭矩的效率较低。然而，即使没有净电荷或设备触点之间流动的旋转电流，也可以利用单个带机制来移动天空。考虑到只有几个电子状态的合奏，我们还能够恢复经典限制。在此极限中，我们发现，由于天空结构对电子电流的影响，即使在弹道纳米线中也需要考虑电子扩散。
In this work we compute the torque field present in a ferromagnet in contact with a metallic nanowire when a skyrmion is present. If the nanowire is narrow enough the current is carried by a single conduction band. In this regime the classical torque model breaks down and we show that a skyrmion driven by spin transfer torque moves in a different direction than predicted by the classical model. However, the amount of charge current required to move a skyrmion with a certain velocity in the single band regime is similar to a classical model of torque where it is implicitly assumed current transport by many conduction bands. The single band regime is more efficient creating spin current from charge current because of the perfect polarization of the single band but is less efficient creating torque from spin current. Nevertheless, it is possible to take profit of the single band regime to move skyrmions even with no net charge or spin current flowing between the device contacts. We have also been able to recover the classical limit considering an ensemble of only a few electronic states. In this limit we have discovered that electron diffusion needs to be considered even in ballistic nanowires due the effect of the skyrmion structure on the electron current.
