Circular Dichroism in Resonant Inelastic X-ray Scattering: Probing Altermagnetic Domains in MnTe

TL;DR

This paper demonstrates that resonant inelastic X-ray scattering circular dichroism (RIXS-CD) can effectively identify and distinguish altermagnetic domains in MnTe by detecting mirror-symmetry breaking and domain occupation through azimuthal dependence.

Contribution

It introduces RIXS-CD as a novel, domain-sensitive technique for probing altermagnetic order and elementary excitations in quantum materials.

Findings

RIXS-CD reveals dominant occupation of a single altermagnetic domain.

Azimuthal dependence indicates mirror-symmetry breaking.

RIXS-CD can differentiate magnetic domains related by crystallographic symmetries.

Abstract

X-ray magnetic circular dichroism provides a means to identify ferromagnetic, chiral, and altermagnetic orders via their time-reversal-symmetry ($\mathcal{T}$) breaking. However, differentiating magnetic domains related by crystallographic symmetries remains a technical challenge. Here we reveal a circular dichroism (CD) in the resonant inelastic x-ray scattering (RIXS) spectra from the altermagnetic MnTe. The azimuthal dependence of the RIXS-CD intensity of the magnon excitations indicates a dominant occupation of a single altermagnetic domain. The RIXS-CD in our scattering geometry is ascribed to the mirror-symmetry breaking associated with the $\mathcal{T}$-broken altermagnetic order. Our results establish RIXS-CD as a domain-sensitive probe of elementary excitations in quantum materials.