Critical behaviour of continuous phase transitions with infinitely many absorbing states

Abstract

A lattice gas model is proposed for the A2 + 2B2 → 2B2A reaction system with particle diffusion. In the model, A2 dissociates in the random dimer-filling mechanism and B2 dissociation is in the end-on dimer-filling mechanism. A reactive window appears and the system exhibits a continuous phase transition from a reactive state to a covered state with infinitely many absorbing states. When the diffusion of particle A and AB is included, there are still infinitely many absorbing states for the continuous phase transition, but it is found that the critical behaviour changes from the directed percolation (DP) class to the pair contact process with diffusion (PCPD) class.