Motile dissenters disrupt the flocking of active granular matter
Motile dissenters disrupt the flocking of active granular matter
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DOI：
10.1103/physreve.101.052615
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发表时间：
2020-05-27
影响因子：
2.4
通讯作者：
Sood, A. K.
中科院分区：
文献类型：
--
作者：
Bera, Pradip K.;Sood, A. K.
我们报道了在没有干预介质的情况下，聚集在毫米大小的两步锥形棒的干燥活性颗粒物质中。在阈值面积分数为0.12的条件下，体系发生簇状相变，粒子间具有较高的取向相关性。然而，一步锥形棒不成群，在成群的颗粒物中被用作活动的异见者。当持不同政见者的比例达到临界值0.3时，系统的集群秩序被完全破坏。系统序参数的变化在持不同意见分数f附近出现最大值，类似于0.05，这表明有序相和无序相之间存在有限大小的交叉。我们的实验带来了异质主动系统中合作行为的破坏，这可能会在现实生活中的例子中产生影响。
We report flocking in the dry active granular matter of millimeter-sized two-step-tapered rods without an intervening medium. The system undergoes the flocking phase transition at a threshold area fraction of similar to 0.12 having high orientational correlations between the particles. However, the one-step-tapered rods do not flock and are used as the motile dissenters in the flock-forming granular matter. At the critical fraction of dissenters of similar to 0.3, the flocking order of the system gets completely destroyed. The variance of the system's order parameter shows a maximum near the dissenter fraction f similar to 0.05, suggesting a finite-size crossover between the ordered and disordered phases. Our experiments bring out the disruption of the cooperative behavior in heterogeneous active systems with possible implications in real-life examples.