论文标题
Skyrmion弹球和障碍物阵列的指向运动
Skyrmion Pinball and Directed Motion on Obstacle Arrays
论文作者
论文摘要
我们检查了与在一个或两个方向上应用的交流驱动器下的一系列障碍物相互作用的天空阵列。对于AC驾驶的单个方向，我们发现Magnus力与障碍物相互作用结合使用，可以产生尺寸增加的椭圆形天空轨道，从而导致局部相位，混乱的相位以及翻译或棘轮轨道。在两个交流驱动器下，它们不相同的$ 90^\ Circ $并在两个方向上应用，Skyrmions形成了包围整数障碍物数量的局部相应轨道，类似于Antidot Lattices中电子弹球效应。作为交流振幅，马格努斯力强度和障碍物尺寸的函数，我们发现即使在底物中没有不对称性的情况下，混乱的散射状态和定向运动也会出现。定向运动遵循周期性底物的不同对称轴，我们观察到各种相反的棘轮效应。 Skyrmion系统中的Magnus力与过度阻尼系统所表现出的有向运动机制的数量要大得多。我们讨论如何使用这些结果以一种受控的方式移动天际。
We examine skyrmions interacting with a square array of obstacles under ac drives applied in one or two directions. For a single direction of ac driving, we find that the Magnus force in conjunction with the obstacle interactions can create elliptical skyrmion orbits of increasing size, leading to localized phases, chaotic phases, and translating or ratcheting orbits. Under two ac drives that are out of phase by $90^\circ$ and applied in two directions, the skyrmions form localized commensurate orbits that encircle an integer number of obstacles, similar to the electron pinball effect observed for electrons in antidot lattices. As a function of ac amplitude, Magnus force strength, and obstacle size, we find that chaotic scattering regimes and directed motion can emerge even in the absence of asymmetry in the substrate. The directed motion follows different symmetry axes of the periodic substrate, and we observe a variety of reversed ratchet effects. The Magnus force in the skyrmion system produces a significantly larger number of directed motion regimes than are exhibited by overdamped systems. We discuss how these results could be used to move skyrmions in a controlled way for possible applications.
