Díaz S A, Reichhardt C, Arovas D P, Saxena A, Reichhardt C J O
Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Department of Physics, University of California San Diego, La Jolla, California 92093, USA.
Phys Rev Lett. 2018 Mar 16;120(11):117203. doi: 10.1103/PhysRevLett.120.117203.
We show using numerical simulations that slowly driven Skyrmions interacting with random pinning move via correlated jumps or avalanches. The avalanches exhibit power-law distributions in their duration and size, and the average avalanche shape for different avalanche durations can be scaled to a universal function, in agreement with theoretical predictions for systems in a nonequilibrium critical state. A distinctive feature of Skyrmions is the influence of the nondissipative Magnus term. When we increase the ratio of the Magnus term to the damping term, a change in the universality class of the behavior occurs, the average avalanche shape becomes increasingly asymmetric, and individual avalanches exhibit motion in the direction perpendicular to their own density gradient.
我们通过数值模拟表明，缓慢驱动的斯格明子与随机钉扎相互作用时，会通过相关跳跃或雪崩式移动。雪崩在持续时间和规模上呈现幂律分布，不同雪崩持续时间的平均雪崩形状可缩放到一个通用函数，这与非平衡临界状态系统的理论预测相符。斯格明子的一个显著特征是非耗散马格努斯项的影响。当我们增大马格努斯项与阻尼项的比值时，行为的普适类会发生变化，平均雪崩形状变得越来越不对称，且单个雪崩会在垂直于其自身密度梯度的方向上运动。
