Persistence exponent in a superantiferromagnetic quenching

TL;DR

This study measures the persistence exponent in a complex 2D spin system with multiple stripe phases, revealing unique decay behavior and temperature independence below the critical point.

Contribution

It introduces a method to measure persistence in a multi-phase 2D Ising model with complex interactions, extending understanding of non-equilibrium dynamics.

Findings

Persistence exponent estimated as 0.42

Results differ from standard Ising and Potts models

Persistence likely independent of temperature below critical point

Abstract

We measure the persistence exponent in a phase separating two-dimensional spin system with non-conserved dynamics quenched in a region with four coexisting stripe phases. The system is an Ising model with nearest neighbor, next-to-the-nearest neighbor and plaquette interactions. Due the particular nature of the ground states, the order parameter is defined in terms of blocks of spins. Our estimate of the persistence exponent, $\theta=0.42$, differs from those of the two-dimensional Ising and four state Potts models. Our procedure allows the study of persistence properties also at finite temperature $T$: our results are compatible with the hypothesis that $\theta$ does not depend on $T$ below the critical point.