2000 character limit reached
Relaxations and rheology near jamming (1106.0714v2)
Published 3 Jun 2011 in cond-mat.soft, cond-mat.dis-nn, and cond-mat.stat-mech
Abstract: We determine the form of the complex shear modulus $G*$ in soft sphere packings near jamming. Viscoelastic response at finite frequency is closely tied to a packing's intrinsic relaxational modes, which are distinct from the vibrational modes of undamped packings. We demonstrate and explain the appearance of an anomalous excess of slowly relaxing modes near jamming, reflected in a diverging relaxational density of states. From the density of states, we derive the dependence of $G*$ on frequency and distance to the jamming transition, which is confirmed by numerics.