Spin Hall and Nernst effects of Weyl magnons

TL;DR

This paper introduces a model of three-dimensional magnetic insulators exhibiting Weyl magnons and surface states, analyzing their Berry curvature-induced transport properties and comparing them to fermionic systems.

Contribution

It presents a simple theoretical model demonstrating Weyl magnons with surface states and calculates their intrinsic transport effects, expanding understanding of magnonic topological phenomena.

Findings

Weyl magnons are realized in a layered magnetic structure.

Surface states with Dirac spectrum are identified.

Intrinsic transport properties due to Berry curvature are calculated.

Abstract

In this paper, we present a simple model of a three-dimensional insulating magnetic structure which represents a magnonic analog of the layered electronic system described in [Phys. Rev. Lett. {\bf 107}, 127205 (2011)]. In particular, our model realizes Weyl magnons as well as surface states with a Dirac spectrum. In this model, the Dzyaloshinskii-Moriya interaction is responsible for the separation of opposite Weyl points in momentum space. We calculate the intrinsic (due to the Berry curvature) transport properties of Weyl and so-called anomalous Hall effect (AHE) magnons. The results are compared with fermionic analogs.