Dauchot O, Marty G, Biroli G
SPEC, CEA-Saclay, Gif-sur-Yvette, France.
Phys Rev Lett. 2005 Dec 31;95(26):265701. doi: 10.1103/PhysRevLett.95.265701. Epub 2005 Dec 27.
The dynamics of a bidimensional dense granular packing under cyclic shear is experimentally investigated close to the jamming transition. Measurement of multipoint correlation functions are produced. The self-intermediate scattering function, displaying slower than exponential relaxation, suggests dynamic heterogeneity. Further analysis of four point correlation functions reveal that the grain relaxations are strongly correlated and spatially heterogeneous, especially at the time scale of the collective rearrangements. Finally, a dynamical correlation length is extracted from a spatiotemporal pattern of mobility. Our experimental results open the way to a systematic study of dynamic correlation functions in granular materials.
在接近堵塞转变的情况下，通过实验研究了二维密集颗粒堆积在循环剪切作用下的动力学。进行了多点相关函数的测量。自中间散射函数显示出比指数弛豫更慢的弛豫，这表明存在动态不均匀性。对四点相关函数的进一步分析表明，颗粒弛豫强烈相关且在空间上不均匀，特别是在集体重排的时间尺度上。最后，从迁移率的时空模式中提取了一个动态相关长度。我们的实验结果为系统研究颗粒材料中的动态相关函数开辟了道路。
