Magnon Hall effect and topology in kagome lattices: A theoretical investigation

TLDR

Ferromagnetic insulators with Dzyaloshinskii‑Moriya interaction exhibit the magnon Hall effect, producing a transverse heat current when a temperature gradient is applied. The study aims to link the magnon Hall effect in two‑dimensional kagome lattices to the topology of their magnon dispersion and to derive the high‑temperature limit of the thermal Hall conductivity as a figure of merit. The authors theoretically analyze the magnon Hall effect by connecting it to the topological properties of kagome lattice dispersions and by comparing the temperature and field dependence of the conductivity in Lu₂V₂O₇ with experimental data. The phase.

Abstract

Ferromagnetic insulators with Dzyaloshinskii-Moriya interaction show the magnon Hall effect, i.e., a transverse heat current upon application of a temperature gradient. In this theoretical investigation we establish a close connection of the magnon Hall effect in two-dimensional kagome lattices with the topology of their magnon dispersion relation. From the topological phase diagram we predict systems which show a change of sign in the heat current in dependence on temperature. Furthermore, we derive the high-temperature limit of the thermal Hall conductivity; this quantity provides a figure of merit for the maximum strength of the magnon Hall effect. Eventually, we compare the temperature and field dependence of the magnon Hall conductivity of the three-dimensional pyrochlore ${\mathrm{Lu}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{7}$ with experimental results.