Universal relaxation dynamics of sphere packings below jamming

Atsushi Ikeda (1, 2) , Takeshi Kawasaki (3) , Ludovic Berthier (4) , Kuniyasu Saitoh (5) , Takahiro Hatano (6)

1 Life Sciences - Graduate School of Arts and Sciences [Tokyo, Japan]
2 Universal Biology Institute
3 Nagoya City University [Nagoya, Japan]
4 L2C - Laboratoire Charles Coulomb
5 GSIS Mathematics - Research Center for Pure and Applied Mathematics, GSIS, Tohoku University
6 Osaka University [Osaka]

We show that non-Brownian suspensions of repulsive spheres below jamming display a slow relaxational dynamics with a characteristic time scale that diverges at jamming. This slow time scale is fully encoded in the structure of the unjammed packing and can be readily measured via the vibrational density of states. We show that the corresponding dynamic critical exponent is the same for randomly generated and sheared packings. Our results show that a wide variety of physical situations, from suspension rheology to algorithmic studies of the jamming transition are controlled by a unique diverging timescale, with a universal critical exponent.

Domaines: Matière Molle [cond-mat.soft]; Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]

Atsushi Ikeda, Takeshi Kawasaki, Ludovic Berthier, Kuniyasu Saitoh, Takahiro Hatano. Universal relaxation dynamics of sphere packings below jamming. Physical Review Letters, 2020, pp.058001. ⟨10.1103/PhysRevLett.124.058001⟩. ⟨hal-02591059⟩