Ultralow-loss domain wall motion driven by a magnetocrystalline anisotropy gradient in an antiferromagnetic nanowire-猫眼课题宝

DOI：

10.1103/physrevresearch.2.013166

发表时间：

2019-05

期刊：

Physical Review Research

影响因子：

4.2

通讯作者：

中科院分区：

文献类型：

作者：

D. L. Wen;Z. Chen;W. H. Li;M. Qin;Deyang Chen;Z. Fan;M. Zeng;Xubing Lu;Xingsen Gao;Jian Liu

寻找控制反铁磁畴壁的新方法是原子力显微镜（AFM）自旋电子器件运行的重要问题之一。在本工作中，我们从理论上研究了由外电场产生的轴向各向异性梯度驱动的AFM纳米线的畴壁运动，从而实现了具有超低能量损失的AFM畴壁运动的电子控制。利用Landau-Lifshitz-Gilbert方程模拟了各向异性梯度大小和材料本征特性对畴壁速度的影响，并利用能量耗散定理进行了推导。结果表明，当梯度较小时，畴壁的运动速度接近恒定；当梯度较大时，畴壁宽度增大，畴壁运动速度加快。畴壁迁移率与晶格尺寸和畴壁类型无关，而Dzyaloshinskii-Moriya相互作用增强了畴壁迁移率。此外，定性地解释了原子力显微镜壁动力学比铁磁壁动力学快得多的物理机制。这项工作揭示了一种很有前途的控制AFM畴壁的策略，有利于未来AFM自旋电子学的应用。

Searching for new methods controlling antiferromagnetic (AFM) domain wall is one of the most important issues for AFM spintronic device operation. In this work, we study theoretically the domain wall motion of an AFM nanowire, driven by the axial anisotropy gradient generated by external electric field, allowing the electro control of AFM domain wall motion in the merit of ultra-low energy loss. The domain wall velocity depending on the anisotropy gradient magnitude and intrinsic material properties is simulated based on the Landau-Lifshitz-Gilbert equation and also deduced using the energy dissipation theorem. It is found that the domain wall moves at a nearly constant velocity for small gradient, and accelerates for large gradient due to the enlarged domain wall width. The domain wall mobility is independent of lattice dimension and types of domain wall, while it is enhanced by the Dzyaloshinskii-Moriya interaction. In addition, the physical mechanism for much faster AFM wall dynamics than ferromagnetic wall dynamics is qualitatively explained. This work unveils a promising strategy for controlling the AFM domain walls, benefiting to future AFM spintronic applications.

Ultralow-loss domain wall motion driven by a magnetocrystalline anisotropy gradient in an antiferromagnetic nanowire

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