Hysteresis properties at zero temperature in the Dipolar-Random Field Ising Model

TL;DR

This paper introduces a modified 2D random field Ising model with dipolar interactions, demonstrating that zero-temperature hysteresis loops resemble those of thin magnetic materials and providing insights into domain nucleation processes.

Contribution

The study extends the classic random field Ising model by adding dipolar interactions, revealing hysteresis behaviors similar to thin magnetic films and clarifying domain nucleation mechanisms.

Findings

Hysteresis loops at zero temperature resemble those of garnet films.

Domain nucleation and wall motion are temporally separated.

Model provides better understanding of nucleation in spin systems.

Abstract

We present a modified two-dimensional random field Ising model, where a dipolar interaction term is added to the classic random field Hamiltonian. In a similar model it was already verified that the system state can exhibit domains in the form of stripe patterns, typical of thin materials with strong perpendicular anisotropy. In this work we show that the hysteresis loops obtained at zero temperature can display a strict similarity with the loops obtained in thin magnetic materials such as garnet films. In our model the processes of domain nucleation and domain wall motion are well separated in time as the system evolves. This remarkable fact allowed us to better understand the nucleation process in this family of spin systems.