Tuning bulk topological magnon properties with light-induced magnons

TL;DR

This paper proposes a method to selectively amplify bulk topological magnons in quantum magnets using uniform electromagnetic fields, enhancing the thermal Hall effect and enabling better experimental detection of topological magnon properties.

Contribution

It introduces a novel approach to amplify bulk topological magnons via uniform electromagnetic fields, breaking inversion symmetry to improve detection of topological effects.

Findings

Demonstrates generation of bulk topological magnons in a breathing kagome lattice.

Shows amplification of thermal Hall effect using electromagnetic fields.

Provides a pathway for experimental detection of topological magnon phenomena.

Abstract

Although theoretical modelling and inelastic neutron scattering measurements have indicated the presence of topological magnon bands in multiple quantum magnets, experiments remain unable to detect signal of magnon thermal Hall effect in the quantum magnets, which is a consequence of magnons condensation at the bottom of the bands following Bose Einstein statistics as well as the concentration of Berry curvature at the higher energies. In a recent work, Malz et al.[Nature Communications 10, 3937 (2019)] have shown that topological magnons in edge states in a finite sample can be amplified using tailored electromagnetic fields. We extend their approach by showing that a uniform electromagnetic field can selectively amplify magnons with finite Berry curvature by breaking inversion symmetry of a lattice. Using this approach, we demonstrate the generation of bulk topological magnons in a Heisenberg ferromagnet on the breathing kagome lattice and the consequent amplification of thermal Hall effect.