Mean-Field Analysis and Monte Carlo Study of an Interacting Two-Species Catalytic Surface Reaction Model

TL;DR

This study investigates the phase diagram and critical behavior of a two-species catalytic surface reaction model, revealing a bicritical point with unique universality class characteristics through Monte Carlo simulations.

Contribution

It demonstrates that mean field analysis fails to capture the phase diagram and identifies the bicritical point's critical behavior as belonging to the even branching annihilating random walk universality class.

Findings

Bicritical point exhibits critical behavior different from directed percolation.

Mean field analysis with correlations up to triplets is insufficient.

Universal interfacial fluctuations are observed at the bicritical point.

Abstract

We study the phase diagram and critical behavior of an interacting one dimensional two species monomer-monomer catalytic surface reaction model with a reactive phase as well as two equivalent adsorbing phase where one of the species saturates the system. A mean field analysis including correlations up to triplets of sites fails to reproduce the phase diagram found by Monte Carlo simulations. The three phases coexist at a bicritical point whose critical behavior is described by the even branching annihilating random walk universality class. This work confirms the hypothesis that the conservation modulo 2 of the domain walls under the dynamics at the bicritical point is the essential feature in producing critical behavior different from directed percolation. The interfacial fluctuations show the same universal behavior seen at the bicritical point in a three-species model, supporting the conjecture that these fluctuations are a new universal characteristic of the model.