Monte Carlo investigation of the tricritical point stability in a three-dimensional Ising metamagnet

TL;DR

This study uses Monte Carlo simulations to investigate the stability of the tricritical point in a three-dimensional Ising metamagnet, finding no evidence of predicted decomposition even at small coupling ratios.

Contribution

It provides the first simulation-based evidence that the tricritical point remains stable in a 3D Ising metamagnet across a range of coupling ratios, challenging mean field theory predictions.

Findings

No decomposition of the tricritical point observed.

Tricritical behavior persists at small coupling ratios.

Simulation results contradict mean field theory predictions.

Abstract

We use Monte Carlo simulations to study multicritical properties of an Ising metamagnet in an external field. According to the mean field theory predictions, a three-dimensional layered metamagnet is expected to display a tricritical point decomposition to a critical endpoint and a bicritical endpoint, when a ratio between intralayer ferromagnetic and interlayer antiferromagnetic couplings becomes sufficiently small. Our simulations show no evidence of such a decomposition and produce a tricritical behaviour even for a coupling ratio as small as R=0.01.