Kwon Jaesuk, Hwang Hee-Kyeong, Hong Jung-Il, You Chun-Yeol
Department of Emerging Materials Science, DGIST, Daegu, 42988, South Korea.
Sci Rep. 2018 Dec 21;8(1):18035. doi: 10.1038/s41598-018-36523-9.
Understanding of domain wall (DW) propagation in a complex structure is an essential first step toward the development of any magnetic-domain based devices including spin-based logic or magnetic memristors. Interfacial Dzyaloshinskii-Moriya interaction (iDMI) in the structure with broken inversion symmetry induces an asymmetrical DW configuration with respect to the direction of in-plane field. Dynamic behaviors of field-driven DW within the film with perpendicular magnetic anisotropy is influenced by DW tilt from the iDMI effect and the corners in the T-shaped structure of the DW path. Images from Kerr microscopy reveal that the iDMI effective field contributes to a tilted structure of DW configuration and evolution along its propagation. With the combination of iDMI and T-shaped structure, we observed two distinguished bidirectional DW propagations in two output branches and distinct arriving times at the destination pads with a uniform external field. Micromagnetic simulation results is compared with the observed dynamics of a DW configuration in the structure providing an additional confirmation of the interpreted results.
理解复杂结构中的畴壁(DW)传播是开发任何基于磁畴的器件(包括自旋逻辑或磁忆阻器)的重要第一步。具有破缺反演对称性的结构中的界面Dzyaloshinskii-Moriya相互作用(iDMI)会诱导出相对于面内场方向不对称的DW构型。具有垂直磁各向异性的薄膜内场驱动DW的动态行为受iDMI效应导致的DW倾斜以及DW路径T形结构中的拐角影响。克尔显微镜图像显示,iDMI有效场有助于DW构型的倾斜结构及其传播过程中的演化。结合iDMI和T形结构,我们在两个输出分支中观察到两种不同的双向DW传播,并且在均匀外场作用下到达目的焊盘的时间不同。将微磁模拟结果与结构中DW构型的观测动态进行比较,进一步证实了解释结果。