Non-equilibrium glass transitions in driven and active matter

Abstract

The glass transition, extensively studied in dense fluids, polymers or colloids, corresponds to a marked evolution of equilibrium transport coefficients on a modest change of control parameter, such as temperature or pressure. A similar phenomenology is found in many systems evolving far from equilibrium, such as driven granular media, active and living matter. Although many theories compete to describe the glass transition at thermal equilibrium, very little is understood far from equilibrium. Here, we solve the dynamics of a specific, yet representative, class of glass models in the presence of non-thermal driving forces and energy dissipation, and show that a dynamic arrest can take place in these non-equilibrium conditions. Whereas the location of the transition depends on the specifics of the driving mechanisms, important features of the glassy dynamics are insensitive to details, suggesting that an effective thermal dynamics generically emerges at long timescales in non-equilibrium systems close to dynamic arrest. Active materials, such as motile cells and self-propelled colloids, exhibit glassy effects, but little is known about the glass transition far from equilibrium. A study of model glasses subject to non-thermal driving and dissipation reveals signatures of dynamic arrest that can be understood in terms of an effective equilibrium description.