Noncollinear Antiferromagnetic Haldane Magnon Insulator

TL;DR

This paper theoretically demonstrates topological magnon bands and a thermal Hall effect in non-collinear antiferromagnetic honeycomb systems with Dzyaloshinskii-Moriya interaction, suggesting potential experimental realizations.

Contribution

It reveals the existence of topological magnon bands and thermal Hall effect in non-collinear antiferromagnets with Dzyaloshinskii-Moriya interaction on the honeycomb lattice, highlighting a new route for magnon transport.

Findings

Topological magnon bands with protected edge modes.

Nonzero thermal magnon Hall effect.

Potential realization in specific honeycomb antiferromagnetic materials.

Abstract

In this Letter we present a comprehensive study of topological magnon bands and thermal Hall effect in non-collinear antiferromagnetic systems on the honeycomb lattice with an intrinsic Dzyaloshinskii-Moriya interaction. We theoretically show that the system possesses topological magnon bands with Chern number protected edge modes accompanied by a nonzero thermal magnon Hall effect. These features result from non-collinearity of the magnetic moments due to an applied out-of-plane magnetic field. Our results provide an experimental clue towards the realization of topological magnon transports in honeycomb antiferromagnetic compounds such as XPS$_3$ (X=Mn,Fe) and $\alpha$-Cu$_2$V$_2$O$_7$.