1] Department of Physics, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany [2] Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany [3] SwissFEL, Paul Scherrer Institute, 5232 Villigen, Switzerland and Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland [4] Institut für Physik, Johannes Gutenberg Universität Mainz, 55128 Mainz, Germany.
Nat Commun. 2013;4:2328. doi: 10.1038/ncomms3328.
Magnetic sensing and logic devices based on the motion of magnetic domain walls rely on the precise and deterministic control of the position and the velocity of individual magnetic domain walls in curved nanowires. Varying domain wall velocities have been predicted to result from intrinsic effects such as oscillating domain wall spin structure transformations and extrinsic pinning due to imperfections. Here we use direct dynamic imaging of the nanoscale spin structure that allows us for the first time to directly check these predictions. We find a new regime of oscillating domain wall motion even below the Walker breakdown correlated with periodic spin structure changes. We show that the extrinsic pinning from imperfections in the nanowire only affects slow domain walls and we identify the magnetostatic energy, which scales with the domain wall velocity, as the energy reservoir for the domain wall to overcome the local pinning potential landscape.
基于磁畴壁运动的磁传感和逻辑器件依赖于对单个磁畴壁在弯曲纳米线中的位置和速度的精确和确定性控制。畴壁速度的变化预计会因内在效应（如畴壁自旋结构的振荡转变）和外在钉扎（由于不完美）而产生。在这里，我们使用纳米级自旋结构的直接动态成像，首次能够直接检验这些预测。我们发现了一种新的畴壁运动振荡模式，即使在低于 Walker 击穿的情况下也与周期性的自旋结构变化有关。我们表明，来自纳米线不完美的外在钉扎仅影响缓慢的畴壁，我们确定了静磁能量，它与畴壁速度成正比，作为畴壁克服局部钉扎势垒的能量储备。
