Translational and Rotational Dynamical Heterogeneities in Granular Systems.
Translational and Rotational Dynamical Heterogeneities in Granular Systems.
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DOI：
10.1103/physrevlett.121.018002
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发表时间：
2018-03
影响因子：
8.6
通讯作者：
Binquan Kou;Yixin Cao;Jindong Li;Chengjie Xia;Zhifeng Li;Hai-peng Dong;Ang Zhang;Jie Zhang;W. Kob;Yujie Wang
中科院分区：
文献类型：
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作者：
Binquan Kou;Yixin Cao;Jindong Li;Chengjie Xia;Zhifeng Li;Hai-peng Dong;Ang Zhang;Jie Zhang;W. Kob;Yujie Wang
本文利用X射线层析技术研究了三维硬椭球颗粒堆积在振荡剪切作用下的平移和旋转动力学不均匀性。我们发现，快速平移的颗粒形成团簇的大小分布由幂律与指数是独立的应变振幅。对于缓慢平移、快速旋转或缓慢旋转的粒子，发现了相同的行为。这四种不同类型的团簇的几何性质与随机团簇的几何性质相同。不同的集群类型是相当相关的或相关的，这表明平移和旋转自由度之间的显着耦合。令人惊讶的是，这些团簇已经在比α-弛豫时间短得多的时间尺度上形成，与玻璃形成系统中发现的行为形成鲜明对比。
We use x-ray tomography to investigate the translational and rotational dynamical heterogeneities of a three dimensional hard ellipsoid granular packing driven by oscillatory shear. We find that particles which translate quickly form clusters with a size distribution given by a power law with an exponent that is independent of the strain amplitude. Identical behavior is found for particles that are translating slowly, rotating quickly, or rotating slowly. The geometrical properties of these four different types of clusters are the same as those of random clusters. Different cluster types are considerably correlated or anticorrelated, indicating a significant coupling between translational and rotational degrees of freedom. Surprisingly, these clusters are formed already at time scales that are much shorter than the α-relaxation time, in stark contrast to the behavior found in glass-forming systems.