电流诱导磁畴壁脱钉的非连续特性

Discontinuous properties of current-induced magnetic domain wall depinning.

作者信息

Hu X F, Wu J, Niu D X, Chen L, Morton S A, Scholl A, Huang Z C, Zhai Y, Zhang W, Will I, Xu Y B, Zhang R, van der Laan G

机构信息

1] Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, York YO10 5DD, UK [2] Nanjing-York International Center of Spintronics, School of Electronics Science and Engineering, Nanjing University, Nanjing 210093, China.

出版信息

Sci Rep. 2013 Oct 30;3:3080. doi: 10.1038/srep03080.

DOI:10.1038/srep03080

PMID:24170087

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3812652/

Abstract

The current-induced motion of magnetic domain walls (DWs) confined to nanostructures is of great interest for fundamental studies as well as for technological applications in spintronic devices. Here, we present magnetic images showing the depinning properties of pulse-current-driven domain walls in well-shaped Permalloy nanowires obtained using photoemission electron microscopy combined with x-ray magnetic circular dichroism. In the vicinity of the threshold current density (Jth = 4.2 × 10(11) A.m(-2)) for the DW motion, discontinuous DW depinning and motion have been observed as a sequence of "Barkhausen jumps". A one-dimensional analytical model with a piecewise parabolic pinning potential has been introduced to reproduce the DW hopping between two nearest neighbour sites, which reveals the dynamical nature of the current-driven DW motion in the depinning regime.

摘要

局限于纳米结构的磁畴壁（DWs）的电流驱动运动，对于基础研究以及自旋电子器件的技术应用都具有极大的吸引力。在此，我们展示了磁图像，这些图像显示了利用光发射电子显微镜结合X射线磁圆二色性获得的形状规整的坡莫合金纳米线中脉冲电流驱动畴壁的去钉扎特性。在畴壁运动的阈值电流密度（Jth = 4.2 × 10(11) A·m(-2)）附近，已观察到不连续的畴壁去钉扎和运动，呈现为一系列“巴克豪森跳跃”。引入了具有分段抛物线钉扎势的一维分析模型，以重现畴壁在两个最近邻位点之间的跳跃，这揭示了去钉扎 regime中电流驱动畴壁运动的动力学本质。