Magnetic order and spin excitations in layered Heisenberg antiferromagnets with compass-model anisotropies

TL;DR

This paper investigates the magnetic properties and spin excitations of layered Heisenberg antiferromagnets with compass-model anisotropies, showing good agreement with experimental data and highlighting the impact of compass interactions on Neel temperature.

Contribution

It provides a theoretical analysis of spin-wave spectra and Neel temperature in a model relevant for iridates, incorporating compass-model anisotropies for the first time.

Findings

Spin-wave spectrum matches Lanczos diagonalization data.

Neel temperature is enhanced by compass-model interaction.

Calculated Neel temperature aligns with experimental value for Ba2IrO4.

Abstract

The spin-wave excitation spectrum, the magnetization, and the N\'{e}el temperature for the quasi-two-dimensional spin-1/2 antiferromagnetic Heisenberg model with compass-model interaction in the plane proposed for iridates are calculated in the random phase approximation. The spin-wave spectrum agrees well with data of Lanczos diagonalization. We find that the Neel temperature is enhanced by the compass-model interaction and is close to the experimental value for Ba2IrO4.