Aging in a Two-Dimensional Ising Model with Dipolar Interactions

TL;DR

This study investigates aging phenomena in a two-dimensional Ising model with competing ferromagnetic and antiferromagnetic interactions, revealing diverse dynamical behaviors depending on interaction ratios and temperature.

Contribution

It demonstrates how varying the ratio of exchange to dipolar interactions influences aging dynamics, bridging ferromagnetic and spin-glass-like behaviors in a non-disordered model.

Findings

Behavior of autocorrelation function varies with temperature and interaction ratio.

Dynamics can resemble slow domain growth or activated processes.

Results connect ferromagnetic and spin-glass dynamics in a unified framework.

Abstract

Aging in a two-dimensional Ising spin model with both ferromagnetic exchange and antiferromagnetic dipolar interactions is established and investigated via Monte Carlo simulations. The behaviour of the autocorrelation function $C(t,t_w)$ is analyzed for different values of the temperature, the waiting time $t_w$ and the quotient $\delta=J_0/J_d$, $J_0$ and $J_d$ being the strength of exchange and dipolar interactions respectively. Different behaviours are encountered for $C(t,t_w)$ at low temperatures as $\delta$ is varied. Our results show that, depending on the value of $\delta$, the dynamics of this non-disordered model is consistent either with a slow domain dynamics characteristic of ferromagnets or with an activated scenario, like that proposed for spin glasses.