Barrier-Controlled Non-Equilibrium Criticality in Reactive Particle Systems

TL;DR

This paper investigates how activation barriers influence non-equilibrium phase transitions in reactive particle systems, revealing a transition from continuous to discontinuous behavior and proposing a theoretical framework to explain these phenomena.

Contribution

It demonstrates the critical role of activation barriers in dynamic phase transitions and introduces a combined simulation and mean-field theory approach to explain the observed criticality changes.

Findings

Transition changes from continuous to discontinuous with increasing barrier

Identification of a tricritical point in the phase diagram

Potential for Ising-type criticality at finite thermal noise

Abstract

Non-equilibrium critical phenomena generally exist in many dynamic systems, like chemical reactions and some driven-dissipative {reactive} particle systems. Here, by using computer simulation and theoretical analysis, we demonstrate the crucial role of the activation barrier on the criticality of dynamic phase transitions in a minimal reactive hard-sphere model. We find that at zero thermal noise, with increasing the activation barrier, the type of transition changes from a continuous conserved directed percolation into a discontinuous dynamic transition by crossing a \emph{tricritical} point. A mean-field theory combined with field-simulation is proposed to explain this phenomenon. The possibility of Ising-type criticality in the non-equilibrium system at finite thermal noise is also discussed.