Multiple topological phases of magnons induced by Dzyaloshinskii-Moriya and pseudodipolar anisotropic exchange interactions in Kagome ferromagnets

TL;DR

This paper explores how multiple magnetic anisotropic interactions in 2D Kagome ferromagnets induce diverse topological magnon phases, revealing new phase diagrams, high Chern number states, and temperature-dependent transport phenomena relevant for magnonic devices.

Contribution

It demonstrates that distinct magnetic anisotropic interactions lead to unique topological phases and transitions in Kagome ferromagnets, expanding understanding of topological magnonics.

Findings

Multiple topological magnon phases with high Chern numbers are identified.

Interplay of DMI and PDI controls various topological phase transitions.

Temperature-induced sign reversal of thermal Hall and Nernst conductivities is observed.

Abstract

Kagome magnets naturally hosting Dirac points and flat bands exhibit novel topological phases, enabling rich interplays between interactions and topologies. The discovery of two-dimensional (2D) magnets generally coexisting with different types of magnetic interactions poses a challenge for topological magnonic manipulation. Here we investigate the topological magnon phases of 2D Kagome ferromagnet with multiple magnetic anisotropic interactions, i.e. Dzyaloshinskii-Moriya interaction (DMI) and pseudo-dipolar interaction (PDI). It is found that the different sole magnetic anisotropic interactions introduce completely distinct topological phase diagrams and topological states. The multiple topological magnon phases with high Chern number emerge due to the distinct anisotropic interactions. Moreover, the interplay of the multiple anisotropic DMI and PDI interactions involved with Dirac and flat bands controls a variety of topological phase transitions, implying greater manipulation potential. In addition, the sign reversal of thermal Hall and Nernst conductivities induced by temperature is found in particular topological phase regions, namely topological origin, relating to the energy gap and Berry curvature (Chern number) in the vicinity of magnetic phase transition from the thermal fluctuations, providing a possible explanation for the experimental puzzles. All these results demonstrate that the novel topological magnonic properties in Kagome magnet with multiple magnetic anisotropic interactions can realize a potential platform for magnonic devices and quantum computing.