Micromagnetic simulation is carried out to investigate the current‐driven domain wall (DW) in a nanowire with perpendicular magnetic anisotropy. A stepped nanowire is proposed to pin DW and achieve high information storage capacity based on multibit per cell scheme. The DW speed is found to increase for thicker and narrower nanowires. For depinning DW from the stepped region, the current density J_dep is investigated with emphasis on device geometry and material intrinsic properties. The J_dep can be analytically determined as a function of the nanoconstriction dimension and the thickness of the nanowire. Furthermore, J_dep is found to exponential dependent on the anisotropy energy and saturation magnetization, offering thus more flexibility in adjusting the writing current for memory applications.

中文翻译：

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具有垂直磁各向异性的阶梯式磁性纳米线的畴壁动力学

进行了微磁仿真，以研究具有垂直磁各向异性的纳米线中的电流驱动畴壁（DW）。提出了一种阶梯式纳米线来固定DW，并基于每单元多位方案实现高信息存储容量。发现对于更粗和更窄的纳米线，DW速度会增加。为了将DW固定在台阶区域之外，研究了电流密度J _dep，重点是器件的几何形状和材料的固有特性。所述Ĵ _DEP可以分析确定为nanoconstriction尺寸的函数，并且所述纳米线的厚度。此外，J _dep 已经发现，电阻的指数取决于各向异性能量和饱和磁化强度，因此在为存储器应用调整写电流时提供了更大的灵活性。