Monte Carlo Simulation of a Random-Field Ising Antiferromagnet

TL;DR

This paper uses Monte Carlo simulations to study phase transitions in a 3D diluted Ising antiferromagnet under magnetic fields, revealing a crossover from second-order to first-order transitions and the emergence of a spin-glass phase.

Contribution

It introduces a numerical analysis of how random magnetic fields induce a phase transition crossover and spin-glass states in diluted antiferromagnets.

Findings

Random magnetic fields cause a transition from second-order to first-order.

A spin-glass phase with metastable states appears at finite temperatures.

Transition behavior depends on spin concentration threshold.

Abstract

Phase transitions in the three-dimensional diluted Ising antiferromagnet in an applied magnetic field are analyzed numerically. It is found that random magnetic field in a system with spin concentration below a certain threshold induces a crossover from second-order phase transition to first-order transition to a new phase characterized by a spin-glass ground state and metastable energy states at finite temperatures.