Unveiling the hidden weak universality of the ZGB model

TL;DR

This study reveals a complex critical line with multiple universality classes in the ZGB model with CO desorption, challenging the traditional view of a single critical point and uncovering weak universality.

Contribution

We demonstrate that the ZGB model with CO desorption exhibits a critical line passing through various universality classes, including Potts and Ising, indicating weak universality.

Findings

Existence of a critical line with multiple universality classes.

Critical line passes through three- and four-state Potts points and Ising point.

Reveals weak universality in the ZGB model with desorption.

Abstract

In this work, we revisited the Ziff-Gullari-Barshad (ZGB) model in order to investigate its critical behavior when carbon monoxide (CO) molecules are allowed to desorb from the catalytic surface. As shown by several authors, when this kind of desorption takes place, the first-order phase transition of the standard model disappears, and an Ising-like critical point is found for a very small value of the desorption rate. However, our time-dependent Monte Carlo simulations reveal that, instead of a single critical point, there exists a critical line that encompasses multiple universality classes, passing through the three- and four-state Potts points, as well as, the Ising one, resulting in an unprecedented critical line of weak universality.