Revisiting the nonequilibrium phase transition of the triplet-creation model

TL;DR

This paper investigates the nonequilibrium phase transition in the triplet-creation model, revealing how increased diffusion causes the transition to become discontinuous and alters critical exponents, with complex crossover effects obscuring the tricritical point.

Contribution

It provides new insights into the nature of phase transitions in the triplet-creation model, especially regarding the effects of diffusion on universality classes and critical behavior.

Findings

High diffusion leads to discontinuous phase transitions.

Critical exponents vary continuously with diffusion.

Abrupt change in fractal dimension between universality classes.

Abstract

The nonequilibrium phase transition in the triplet-creation model is investigated using critical spreading and the conservative diffusive contact process. The results support the claim that at high enough diffusion the phase transition becomes discontinuous. As the diffusion probability increases the critical exponents change continuously from the ordinary directed percolation (DP) class to the compact directed percolation (CDP). The fractal dimension of the critical cluster, however, switches abruptly between those two universality classes. Strong crossover effects in both methods make it difficult, if not impossible, to establish the exact location of the tricritical point.