Persistence of pinning and creep beyond critical drive within the strong pinning paradigm
Persistence of pinning and creep beyond critical drive within the strong pinning paradigm
复制标题
在强钉扎范式中，钉扎和蠕变的持续性超出了临界驱动力
DOI：
10.1103/physrevb.98.094510
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发表时间：
2018
影响因子：
3.7
通讯作者：
G. Blatter
中科院分区：
文献类型：
--
作者：
M. Buchacek;R. Willa;V. Geshkenbein;G. Blatter
钉扎和热蠕变决定了许多包含超结构的系统的响应，例如 II 型超导体中的涡流、铁磁性材料中的畴壁或金属中的位错。驱动力和热波动的结合导致上部结构脱钉，其速度 $v$ 决定了电、磁或机械响应。人们普遍认为，钉扎和蠕变在临界驱动 $F_c$ 之上崩溃，导致速度 $v$ 急剧上升。我们通过研究 II 型超导体中强涡钉扎框架内的热波动的影响来挑战这种看法。事实上，我们表明钉扎和热蠕变的持续性远远超出了临界力。由此产生的力-速度特性在很大程度上保持其零温度形状，并且热蠕变通过临界驱动的向下重正化来表现出来。这种特性与库仑干摩擦定律一致，并且在实验中经常观察到。
Pinning and thermal creep determine the response of numerous systems containing superstructures, e.g., vortices in type II superconductors, domain walls in ferroics, or dislocations in metals. The combination of drive and thermal fluctuations lead to the superstructure's depinning and its velocity $v$ determines the electric, magnetic, or mechanical response. It is commonly believed that pinning and creep collapse above the critical drive $F_c$, entailing a sharp rise in the velocity $v$. We challenge this perception by studying the effects of thermal fluctuations within the framework of strong vortex pinning in type-II superconductors. In fact, we show that pinning and thermal creep persist far beyond the critical force. The resulting force-velocity characteristic largely maintains its zero-temperature shape and thermal creep manifests itself by a downward renormalisation of the critical drive. Such characteristics is in agreement with Coulomb's law of dry friction and has been often observed in experiments.