论文标题
磁性涡流核心极性的重复确定性缺陷辅助切换
Repeated deterministic defect-assisted switching of magnetic vortex core polarity
论文作者
论文摘要
由于其稳定性，磁性涡流芯（VC）的极性是二进制数据存储的候选者。可以通过将VC驱动到关键速度$ v_c $上方来完成切换。在这里，我们通过大大减少本地$ v_c $的方式来报告VC极性的受控和重复转换。我们用磁场脉冲激发了薄膜磁盘中的涡旋动力学，并使用时间分辨的KERR显微镜绘制二维VC轨迹。在原始样品中，我们观察到VC的正常旋转运动。但是，在激光诱导的缺陷产生后，我们观察到在大量减少的临界速度低至20 m/s的临界速度下重复的VC逆转。微磁模拟揭示了局部减少交换耦合如何创建VC反转位点，以确定性VC开关。
Because of its stability, the polarity of a magnetic vortex core (VC) is a candidate for binary data storage. Switching can be accomplished, e.g, by driving the VC above a critical velocity $v_c$. Here, we report on controlled and repeated switching of VC polarity by significantly reducing $v_c$ locally. We excite vortex dynamics in thin Permalloy disks with a magnetic field pulse, and map the two-dimensional VC trajectory using time-resolved Kerr microscopy. In pristine samples, we observe normal gyrotropic motion of the VC. After laser-induced generation of defects, however, we observe repeated VC reversal at much-reduced critical velocities as low as 20 m/s. Micromagnetic simulations reveal how local reduction of exchange coupling can create VC reversal sites for deterministic VC switching.
