Abstract
In periodically sheared suspensions there is a dynamical phase transition, characterized by a critical strain amplitude , between an absorbing state where particle trajectories are reversible and an active state where trajectories are chaotic and diffusive. Repulsive nonhydrodynamic interactions between “colliding” particles’ surfaces have been proposed as a source of this broken time reversal symmetry. A simple toy model called random organization qualitatively reproduces the dynamical features of this transition. Random organization and other absorbing state models exhibit hyperuniformity, a strong suppression of density fluctuations on long length scales quantified by a structure factor with , at criticality. Here we show experimentally that the particles in periodically sheared suspensions organize into structures with anisotropic short-range order but isotropic, long-range hyperuniform order when oscillatory shear amplitudes approach .
- Received 11 February 2020
- Revised 21 May 2020
- Accepted 1 July 2020
DOI:https://doi.org/10.1103/PhysRevLett.125.148001
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