Metastable states in the J1-J2 Ising model

TL;DR

This study investigates the metastable states in the J1-J2 Ising model on a square lattice, revealing their dependence on initial conditions, external fields, and temperature through theoretical and simulation methods.

Contribution

It introduces the prediction and analysis of metastable states with zero and arbitrary polarization in the J1-J2 Ising model using RLFA and Monte Carlo simulations.

Findings

Metastable states with zero polarization predicted at low temperatures.

Monte Carlo simulations show states with arbitrary polarization depending on initial conditions.

Energy barriers for metastable states are calculated and discussed.

Abstract

We study the J1-J2 Ising model on the square lattice using the random local field approximation (RLFA) and Monte Carlo (MC) simulations for various values of the ratio p = J2/|J1| with antiferromagnetic coupling J2, ensuring spin frustration. RLFA predicts metastable states with zero order parameter (polarization) at low temperature for p \in (0,1). This is supported by our MC simulations, in which the system relaxes into metastable states with not only zero, but also with arbitrary polarization, depending on its initial value, external field, and temperature. We support our findings by calculating the energy barriers of these states at the level of individual spin flips relevant to the MC calculation. We discuss experimental conditions and compounds appropriate for experimental verification of our predictions.