Max Planck Institute for Microstructure Physics, Halle (Saale), D-06120, Germany.
Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany.
Nat Commun. 2018 Nov 26;9(1):4984. doi: 10.1038/s41467-018-07373-w.
Highly efficient current-induced motion of chiral domain walls was recently demonstrated in synthetic antiferromagnetic (SAF) structures due to an exchange coupling torque (ECT). The ECT derives from the antiferromagnetic exchange coupling through a ruthenium spacer layer between the two perpendicularly magnetized layers that comprise the SAF. Here we report that the same ECT mechanism applies to ferrimagnetic bi-layers formed from adjacent Co and Gd layers. In particular, we show that the ECT is maximized at the temperature T where the Co and Gd angular momenta balance each other, rather than at their magnetization compensation temperature T. The current induced velocity of the domain walls is highly sensitive to longitudinal magnetic fields but we show that this not the case near T. Our studies provide new insight into the ECT mechanism for ferrimagnetic systems. The high efficiency of the ECT makes it important for advanced domain wall based spintronic devices.
最近，由于交换耦合扭矩（ECT），在人工反铁磁（SAF）结构中证明了手性畴壁的高效电流诱导运动。ECT 源自通过构成 SAF 的两个垂直磁化层之间的钌间隔层的反铁磁交换耦合。在这里，我们报告相同的 ECT 机制适用于由相邻 Co 和 Gd 层形成的亚铁磁双层。具体来说，我们表明 ECT 在 Co 和 Gd 角动量相互平衡的温度 T 处最大化，而不是在其磁化补偿温度 T 处。畴壁的电流诱导速度对纵向磁场非常敏感，但我们表明在 T 附近并非如此。我们的研究为亚铁磁系统的 ECT 机制提供了新的见解。ECT 的高效率使其在先进的基于畴壁的自旋电子器件中非常重要。
