Numerical study of the spin-3/2 Ashkin-Teller model

TL;DR

This paper uses Monte Carlo simulations to explore the phase diagram of the spin-3/2 Ashkin-Teller model, revealing new phases and multicritical points not seen in lower-spin variants.

Contribution

It provides the first detailed phase diagram of the spin-3/2 ATM, identifying novel high-temperature partially ordered and ground states.

Findings

Discovery of a new high-temperature partially ordered phase $ angle S angle$

Identification of a new Baxter 3/2 ground state

Observation of second order transitions and multicritical points

Abstract

The study of the Ashkin-Teller model (ATM) of spin-3/2 on a hypercubic lattice is undertaken via Monte Carlo simulation. The phase diagrams are displayed and discussed in the physical parameter space. Rich physical properties are recovered, namely the second order transition and multicritical points. The phase diagrams have been obtained by varying the strength describing the four spin interaction and the single ion potential. This model shows a new high temperature partially ordered phase, called $\langle S\rangle$ and a new Baxter 3/2 ground state which do not exist either in the spin-1/2 ATM or in the spin-1 ATM.