Chiral spin-wave excitations of the spin-5/2 trimers in the langasite compound Ba3NbFe3Si2O14

TL;DR

This paper presents a theoretical analysis of chiral spin-wave excitations in the antiferromagnetic langasite compound Ba3NbFe3Si2O14, focusing on the spin-5/2 Fe trimers and their interactions, aligning well with experimental neutron scattering data.

Contribution

It introduces a model that treats strongly coupled Fe trimers and includes inter-trimer interactions, providing a better understanding of the magnetic excitations in this compound.

Findings

Good agreement with neutron scattering experiments

Development of a model for spin-wave excitations in Fe trimers

Comparison with linear spin-wave theory

Abstract

The inelastic scattering of neutrons from magnetic excitations in the antiferromagnetic phase of the langasite compound Ba3NbFe3Si2O14 is analyzed theoretically. In the calculations presented, the strongly coupled spin-5/2 Fe triangles are accounted for as trimerized units. The weaker interactions between the trimers are included within the mean-field/random-phase approximation. The theory is compared with linear spin-wave theory, and a model is developed which leads to good agreement with the published results from unpolarized and polarized neutron-scattering experiments.