Topological magnons on the triangular kagome lattice

TL;DR

This paper investigates the topological properties of magnons on the triangular kagome lattice, revealing rich band structures, high Chern numbers, and potential applications in quantum magnonics and sensing.

Contribution

It introduces a detailed topological analysis of magnons on the TKL, including calculations of Berry curvature, Chern numbers, and edge states, highlighting its potential for quantum applications.

Findings

Rich topological magnon band structure with high Chern numbers

Presence of magnon edge states and edge currents

Potential for quantum magnonic devices and sensors

Abstract

We present the topology of magnons on the triangular kagome lattice (TKL) by calculating its Berry curvature, Chern number and edge states. In addition to the ferromagnetic state, the TKL hosts ferrimagnetic ground state as its two sublattices can couple with each other either ferromagnetically or antiferromagnetically. Using Holstein-Primakoff (HP) boson theory and Green's function approach, we find that the TKL has a rich topological band structure with added high Chern numbers compared with the kagome and honeycomb lattices. The magnon edge current allows a convenient calculation of thermal Hall coefficients and the orbital angular momentum gives correlation to the Einstein-de Haas effect. We apply the calculations to the TKL and derive the topological gyromagnetic ratio showing a nonzero Einstein-de Haas effect in the zero temperature limit. Our results render the TKL as a potential platform for quantum magnonics applications including high-precision mechanical sensors and information transmission.