Mallick Sougata, Sassi Yanis, Prestes Nicholas Figueiredo, Krishnia Sachin, Gallego Fernando, M Vicente Arche Luis, Denneulin Thibaud, Collin Sophie, Bouzehouane Karim, Thiaville André, Dunin-Borkowski Rafal E, Jeudy Vincent, Fert Albert, Reyren Nicolas, Cros Vincent
Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, France.
Department of Physics and Nanotechnology, College of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India.
Nat Commun. 2024 Oct 1;15(1):8472. doi: 10.1038/s41467-024-52210-y.
The last decade has seen significant improvements in our understanding of skyrmions current induced dynamics, along with their room temperature stabilization, however, the impact of local material inhomogeneities still remains an issue that impedes reaching the regime of steady state motion of these spin textures. Here, we study the spin-torque driven motion of skyrmions in synthetic ferrimagnetic multilayers with the aim of achieving high mobility and reduced skyrmion Hall effect. We consider Pt|Co|Tb multilayers of various thicknesses with antiferromagnetic coupling between the Co and Tb magnetization. The increase of Tb thickness in the multilayers reduces the total magnetic moment and increases the spin-orbit torques allowing to reach velocities up to 400 ms for skyrmions with diameters of about 160 nm. We demonstrate that due to reduced skyrmion Hall effect combined with the edge repulsion of the magnetic track, the skyrmions move along the track without any transverse deflection. Further, by comparing the field-induced domain wall motion and current-induced skyrmion motion, we demonstrate that the skyrmions at the largest current densities present all the characteristics of a dynamical flow regime.
在过去十年中，我们对斯格明子电流诱导动力学的理解有了显著进步，同时它们在室温下也能稳定存在。然而，局部材料不均匀性的影响仍然是一个问题，阻碍了这些自旋纹理达到稳态运动状态。在此，我们研究了合成亚铁磁多层膜中斯格明子的自旋扭矩驱动运动，目的是实现高迁移率并降低斯格明子霍尔效应。我们考虑了不同厚度的Pt|Co|Tb多层膜，其中Co和Tb磁化之间存在反铁磁耦合。多层膜中Tb厚度的增加会降低总磁矩并增加自旋轨道扭矩，使得直径约为160nm的斯格明子能够达到高达400m/s的速度。我们证明，由于斯格明子霍尔效应的降低以及磁迹的边缘排斥，斯格明子沿着磁迹移动而没有任何横向偏转。此外，通过比较场诱导畴壁运动和电流诱导斯格明子运动，我们证明了在最大电流密度下的斯格明子呈现出动态流态的所有特征。
