Avalanches and disorder-induced criticality in artificial spin ices
Avalanches and disorder-induced criticality in artificial spin ices
复制标题
DOI：
10.1088/1367-2630/16/6/063051
复制
发表时间：
2014-01
影响因子：
3.3
通讯作者：
G. Chern;C. Reichhardt;C. J. Olson Reichhardt
中科院分区：
文献类型：
--
作者：
G. Chern;C. Reichhardt;C. J. Olson Reichhardt
我们发现，无论是广场和kagome人工自旋冰系统表现出无序诱导的非平衡相变，幂律雪崩分布在临界无序水平。两种晶格中不同性质的几何挫折产生不同类型的临界雪崩行为。对于方冰，雪崩涉及的传播的局部稳定的畴壁分离的两个极化的基态，和缩放崩溃同意与界面脱钉机制。相比之下，在完全受挫的戈薇冰雪崩表现出明显的分支行为，类似于那些在定向渗滤。在鹿尾冰也显示了一个有趣的交叉幂律缩放的雪崩在低无序。结果表明，人工自旋冰是研究非平衡临界点现象的理想体系。
We show that both square and kagome artificial spin ice systems exhibit disorder-induced nonequilibrium phase transitions, with power law avalanche distributions at the critical disorder level. The different nature of geometrical frustration in the two lattices produces distinct types of critical avalanche behavior. For the square ice, the avalanches involve the propagation of locally stable domain walls separating the two polarized ground states, and the scaling collapse agrees with an interface depinning mechanism. In contrast, avalanches in the fully frustrated kagome ice exhibit pronounced branching behaviors that resemble those found in directed percolation. The kagome ice also shows an interesting crossover in the power-law scaling of the avalanches at low disorder. Our results show that artificial spin ices are ideal systems in which to study nonequilibrium critical point phenomena.