# Indirect Chiral Magnetic Exchange through Dzyaloshinskii-Moriya--Enhanced RKKY Interactions in Manganese Oxide Chains on Ir(100)

## TL;DR

This study demonstrates the existence of indirect chiral magnetic exchange mediated by Dzyaloshinskii-Moriya interactions in MnO₂ chains on Ir(100), combining experimental and theoretical methods to reveal spin spirals and chiral coupling.

## Contribution

It provides experimental and theoretical evidence for Dzyaloshinskii-Moriya-enhanced RKKY interactions causing chiral magnetic order in manganese oxide chains on iridium.

## Key findings

- Chiral inter-chain coupling with 120° rotation observed.
- Spin spirals with periodicity matching experiments.
- Confirmation of indirect chiral magnetic exchange mechanism.

## Abstract

Ruderman-Kittel-Kasuya-Yosida interaction even if their wave functions lack direct overlap. Theory predicts that spin-orbit scattering leads to a Dzyaloshinskii-Moriya type enhancement of this indirect exchange interaction, giving rise to chiral exchange terms. Here we present a combined spin-polarized scanning tunneling microscopy, angle-resolved photoemission, and density functional theory study of MnO$_2$ chains on Ir(100). Whereas we find antiferromagnetic Mn--Mn coupling along the chain, the inter-chain coupling across the non-magnetic Ir substrate turns out to be chiral with a $120^{\circ}$ rotation between adjacent MnO$_2$ chains. Calculations reveal that the Dzyaloshinskii-Moriya interaction results in spin spirals with a periodicity in agreement with experiment. Our findings confirm the existence of indirect chiral magnetic exchange, potentially giving rise to exotic phenomena, such as chiral spin-liquid states in spin ice systems or the emergence of new quasiparticles.