Coupled dynamical phase transitions in driven disk packings

TL;DR

This paper investigates two coupled dynamical phase transitions in driven granular disks under oscillatory shear, revealing their coincident critical point and complex trajectory behaviors.

Contribution

It uncovers the simultaneous occurrence of disorder-order and active-absorbing phase transitions in driven disk packings, highlighting their coupling and trajectory characteristics.

Findings

Transitions occur at the same critical point.

Disk trajectories form non-trivial loops breaking time-reversal symmetry.

Identifies two coupled dynamical phase transitions.

Abstract

Under the influence of oscillatory shear, a mono-layer of frictional granular disks exhibits two dynamical phase transitions: a transition from an initially disordered state to an ordered crystalline state, and a dynamic active-absorbing phase transition. Although there is no reason, {\it a-priori}, for these to be at the same critical point, they are. The transitions may also be characterized by the disk trajectories, which are non-trivial loops breaking time-reversal invariance.