Critical Behavior Analysis of Pure Dipolar Triangular Lattice via Equilibrium and Non-Equilibrium Monte Carlo Simulations

TL;DR

This study investigates the critical behavior of a 2D triangular lattice of XY dipoles using advanced Monte Carlo methods, revealing potential new universality class characteristics close to the 2D Ising model.

Contribution

It introduces an optimized Monte Carlo algorithm for dipolar systems and compares equilibrium and non-equilibrium approaches to identify critical properties.

Findings

Critical temperature and exponents estimated with two methods.

System may belong to a new universality class near 2D Ising.

Demonstrates effectiveness of optimized Monte Carlo for dipolar interactions.

Abstract

Magnetic thin films and 2D arrays of magnetic nanoparticles exhibit unique physical properties that make them valuable for a wide range of technological applications. In such systems, dipolar interactions play a crucial role in determining their physical behavior. However, due to the anisotropic and long-range nature of dipolar interactions, conventional Monte Carlo (MC) methods face challenges in investigating these systems near criticality. In this study, we examine the critical behavior of a triangular lattice of XY dipoles using the optimized Tomita MC algorithm tailored for dipolar interactions. We employ two independent computational approaches to estimate the critical temperature and exponents: equilibrium MC simulations with histogram reweighting and the non-equilibrium relaxation method. Notably, both approaches demonstrate that this XY dipolar system might be in a new universality class very close to the 2D Ising universality class.