Reichhardt Charles, Reichhardt Cynthia J O
Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
Sci Rep. 2020 Jul 15;10(1):11625. doi: 10.1038/s41598-020-68417-0.
We examine driven superconducting vortices interacting with quenched disorder under a sequence of perpendicular drive pulses. As a function of disorder strength, we find four types of behavior distinguished by the presence or absence of memory effects. The fragile and jammed states exhibit memory, while the elastic and pinning dominated regimes do not. In the fragile regime, the system organizes into a pinned state during the first pulse, flows during the second perpendicular pulse, and then returns to a pinned state during the third pulse which is parallel to the first pulse. This behavior is the hallmark of the fragility proposed for jamming in particulate matter. For stronger disorder, we observe a robust jamming state with memory where the system reaches a pinned or reduced flow state during the perpendicular drive pulse, similar to the shear jamming of granular systems. We show signatures of the different states in the spatial vortex configurations, and find that memory effects arise from coexisting elastic and pinned components of the vortex assembly. The sequential perpendicular driving protocol we propose for distinguishing fragile, jammed, and pinned phases should be general to the broader class of driven interacting particles in the presence of quenched disorder.
我们研究了在一系列垂直驱动脉冲下，受驱动的超导涡旋与猝灭无序相互作用的情况。作为无序强度的函数，我们发现了四种行为类型，其区别在于是否存在记忆效应。脆弱态和堵塞态表现出记忆效应，而弹性态和钉扎主导态则没有。在脆弱态中，系统在第一个脉冲期间组织成一个钉扎态，在第二个垂直脉冲期间流动，然后在与第一个脉冲平行的第三个脉冲期间回到钉扎态。这种行为是在颗粒物质中提出的堵塞脆弱性的标志。对于更强的无序，我们观察到一种具有记忆效应的稳健堵塞态，其中系统在垂直驱动脉冲期间达到钉扎态或流量减小的状态，类似于颗粒系统的剪切堵塞。我们展示了不同状态在空间涡旋构型中的特征，并发现记忆效应源于涡旋集合中弹性和钉扎成分的共存。我们提出的用于区分脆弱态、堵塞态和钉扎态的顺序垂直驱动协议，对于存在猝灭无序的更广泛的受驱动相互作用粒子类应该是通用的。
