Persistence in an antiferromagnetic Ising model with conserved magnetisation

TL;DR

This study investigates persistence exponents in an antiferromagnetic Ising model with conserved magnetisation, revealing nonuniversal behavior dependent on the conserved field, contrasting with traditional expectations of universality.

Contribution

It provides the first numerical analysis showing that persistence exponents depend on the conserved magnetisation in such systems, challenging prior assumptions of universality.

Findings

Persistence exponents depend on conserved magnetisation.

Nonuniversality is observed in both 2D and 3D.

Results differ from Model A predictions.

Abstract

We obtain the persistence exponents for an antiferromagnetic Ising system in which the magnetisation is kept constant. This system belongs to Model C (system with non-conserved order parameter with a conserved density) and is expected to have persistence exponents different from that of Model A (system with no conservation) but independent of the conserved density. Our numerical results for both local persistence at zero temperature and global persistence at the critical temperature however indicate that the exponents are dependent on the conserved magnetisation in both two and three dimensions. This nonuniversal feature is attributed to the presence of the conserved field and is special to the persistence phenomena.