# Topological Magnetic Excitations on the Distorted Kagome Antiferromagnets: Applications to Volborthite, Vesignieite, and Edwardsite

## TL;DR

This paper investigates topological magnetic excitations in distorted kagome antiferromagnets induced by magnetic fields, explaining recent thermal Hall effects observed in materials like volborthite without relying on Dzyaloshinskii-Moriya interactions.

## Contribution

It introduces a noncoplanar chiral spin texture in distorted kagome antiferromagnets caused by magnetic fields, revealing topological excitations and thermal Hall responses independent of DM interactions.

## Key findings

- Identification of noncoplanar chiral spin textures under magnetic fields.
- Observation of topological magnetic excitations and thermal Hall effect.
- Explanation of experimental thermal Hall conductivity in volborthite without DM interactions.

## Abstract

In this Letter, we identify a noncoplanar chiral spin texture on the distorted kagom\'e-lattice antiferromagnets induced by the presence of a magnetic field applied perpendicular to the distorted kagom\'e plane. The noncoplanar chiral spin texture has a nonzero scalar spin chirality similar to a chiral quantum spin liquid with broken time-reversal symmetry. In the noncoplanar regime we observe nontrivial topological magnetic excitations and thermal Hall response through the emergent field-induced scalar spin chirality in contrast to collinear ferromagnets in which the Dzyaloshinskii-Moriya (DM) spin-orbit interaction is the driving force. Our results shed light on recent observation of thermal Hall conductivity in distorted kagom\'e volborthite at nonzero magnetic field with no signal of DM spin-orbit interaction, and the results also apply to other distorted kagom\'e antiferromagnets such as vesignieite and edwardsite.