Role of Antisymmetric Exchange in Selecting Magnetic Chirality in Ba$_3$NbFe$_3$Si$_2$O$_{14}$

TL;DR

This study uses ESR to identify Dzyaloshinsky-Moriya interaction as the key factor in determining magnetic chirality in Ba3NbFe3Si2O14, revealing how a small out-of-plane DM component stabilizes a unique magnetic ground state.

Contribution

It demonstrates the role of a tiny out-of-plane Dzyaloshinsky-Moriya interaction in selecting magnetic chirality in a complex multichiral magnetic material.

Findings

Dzyaloshinsky-Moriya interaction is the dominant anisotropy term.

A small out-of-plane DM component stabilizes a single magnetic ground state.

The ground state persists up to high temperatures.

Abstract

We present electron spin resonance (ESR) investigation of the acentric \FeLang, featuring a unique single-domain double-chiral magnetic ground state. Combining simulations of the ESR line-width anisotropy and the antiferromagnetic-resonance modes allows us to single out the Dzyaloshinsky-Moriya (DM) interaction as the leading magnetic anisotropy term. We demonstrate that the rather minute out-of-plane DM component $d_c=45$ mK is responsible for selecting a unique ground state, which endures thermal fluctuations up to astonishingly high temperatures.