Criticality and correlated dynamics at the irreversibility transition in periodically driven colloidal suspensions

TL;DR

This study investigates the irreversibility transition in periodically driven colloidal suspensions, identifying critical behavior and universality class through detailed numerical analysis of correlation functions and dynamics.

Contribution

The paper introduces a simple numerical model to characterize the non-equilibrium phase transition and determines critical exponents aligning with directed percolation universality class.

Findings

Critical exponents match directed percolation universality class.

Correlation functions show divergence near the transition.

Dynamics exhibit intermittency and spatial correlations over diverging scales.

Abstract

One possible framework to interpret the irreversibility transition observed in periodically driven colloidal suspensions is that of a non-equilibrium phase transition towards an absorbing reversible state at low amplitude of the driving force. We consider a simple numerical model for driven suspensions which allows us to characterize in great detail a large body of physical observables that can be experimentally determined to assess the existence and universality class of such a non-equilibrium phase transition. Characterizing the behaviour of static and dynamic correlation functions both in real and Fourier space we determine in particular several critical exponents for our model, which take values that are in good agreement with the universality class of direct ed percolation. We also provide a detailed analysis of single-particle and collective dynamics of the system near the phase transition, which appear intermittent and spatially correlated over diverging timescales and lengthscales, and provide clear signatures of the underlying criticality.