Nonclassical effects and off-diagonal couplings in a model for FeBr2

TL;DR

This paper uses Monte Carlo simulations to explore how quantum effects and off-diagonal exchange interactions influence the complex magnetic phase transitions in FeBr2, providing insights into observed experimental anomalies.

Contribution

It introduces a model incorporating quantum S=1 spins and off-diagonal couplings to explain transition-like phenomena in FeBr2.

Findings

Quantum nature of S=1 spins affects phase transitions.

Off-diagonal exchange interactions contribute to anomalies.

Monte Carlo results align with experimental observations.

Abstract

Using Monte Carlo techniques, we show that the recently experimentally observed transitionlike phenomena in the transverse spin-ordering close to the anomalies in the antiferromagnetic phase of FeBr2 (Petracic et al. [Phys. Rev. B 57, R11051 (1998)]) may result from the quantum nature of the S=1 spins and an off-diagonal exchange between axial and planar spin components.