The interplay of Dzyaloshinskii-Moriya and Kitaev interactions for magnonic properties of Heisenberg-Kitaev honeycomb ferromagnets

TL;DR

This paper investigates how Dzyaloshinskii-Moriya and Kitaev interactions influence magnonic topological properties in honeycomb ferromagnets, proposing methods to distinguish their effects via transport measurements.

Contribution

It demonstrates that magnonic transport properties can be used to separately identify the magnitude of Kitaev and Dzyaloshinskii-Moriya interactions in two-dimensional materials.

Findings

Magnonic topological properties are affected by both interactions.

Magnetic field modifies magnonic transport, revealing interaction strengths.

Strategies are proposed to estimate Kitaev interaction importance.

Abstract

The properties of Kitaev materials are attracting ever increasing attention owing to their exotic properties. In realistic two-dimensional materials, Kitaev interaction is often accompanied by the Dzyloshinskii-Moriya interaction, which poses a challenge of distinguishing their magnitude separately. In this work, we demonstrate that it can be done by accessing magnonic transport properties. By studying honeycomb ferromagnets exhibiting Dzyaloshinskii-Moriya and Kitaev interactions simultaneously, we reveal non-trivial magnonic topological properties accompanied by intricate magnonic transport characteristics as given by thermal Hall and magnon Nernst effects. We also investigate the effect of a magnetic field, showing that it does not only break the symmetry of the system but also brings drastic modifications to magnonic topological transport properties, which serve as hallmarks of the relative strength of anisotropic exchange interactions. Based on our findings, we suggest strategies to estimate the importance of Kitaev interactions in real materials.