Interacting Monomer-Dimer Model with Infinitely Many Absorbing States

TL;DR

This paper introduces a modified interacting monomer-dimer model with infinitely many absorbing states, revealing unique universality class behavior and demonstrating how to restore directed percolation universality.

Contribution

It presents a novel IMD model with infinitely many absorbing states divided into two dynamically separated groups, showing it belongs to the directed Ising class, unlike previous models.

Findings

Model belongs to directed Ising universality class.

Does not belong to directed percolation universality class.

Restoring DP class by connecting groups or symmetry-breaking.

Abstract

We study a modified version of the interacting monomer-dimer (IMD) model that has infinitely many absorbing (IMA) states. Unlike all other previously studied models with IMA states, the absorbing states can be divided into two equivalent groups which are dynamically separated infinitely far apart. Monte Carlo simulations show that this model belongs to the directed Ising universality class like the ordinary IMD model with two equivalent absorbing states. This model is the first model with IMA states which does not belong to the directed percolation (DP) universality class. The DP universality class can be restored in two ways, i.e., by connecting the two equivalent groups dynamically or by introducing a symmetry-breaking field between the two groups.