Topological properties of multilayer magnon insulators

TL;DR

This paper explores the topological phases of multilayer magnon insulators with honeycomb lattices, revealing how Dzyaloshinskii-Moriya interactions and layer number influence thermal Hall effects and topological properties.

Contribution

It introduces a comprehensive phase diagram for multilayer magnon insulators, highlighting the even-odd layer effect and topological proximity phenomena, advancing control over topological magnons.

Findings

Topological phase transitions are driven by DMI and interlayer coupling adjustments.

Odd-layered systems exhibit jumps in thermal Hall conductivity, unlike even-layered systems.

Topological proximity effects are observed in trilayer systems.

Abstract

Two-dimensional magnetic insulators can be promising hosts for topological magnons. In this study, we show that ABC-stacked honeycomb lattice multilayers with alternating Dzyaloshinskii-Moriya interaction (DMI) reveal a rich topological magnon phase diagram. Based on our bandstructure and Berry curvature calculations, we demonstrate jumps in the thermal Hall behavior that corroborate with topological phase transitions triggered by adjusting the DMI and interlayer coupling. We connect the phase diagram of generic multilayers to a bilayer and a trilayer system. We find an even-odd effect amongst the multilayers where the even layers show no jump in thermal Hall conductivity, but the odd layers do. We also observe the presence of topological proximity effect in our trilayer. Our results offer new schemes to manipulate Chern numbers and their measurable effects in topological magnonic systems.