Circular Dichroism in Resonant Inelastic X-Ray Scattering: Probing Altermagnetic Domains in MnTe
D. Takegami, Takuya Aoyama, T. Okauchi, Tatsuya Yamaguchi, Sahil Tippireddy, Stefano Agrestini, Mirian García‐Fernández, T. Mizokawa, Kenya Ohgushi, Ke‐Jin Zhou, Jiří Chaloupka, J. Kuneš, Atsushi Hariki, H. Suzuki
Abstract
X-ray magnetic circular dichroism provides a means to identify ferromagnetic, chiral, and altermagnetic orders via their time-reversal-symmetry (T) breaking. However, the symmetry properties that govern circular dichroism (CD) in resonant inelastic x-ray scattering (RIXS) remain poorly understood. We show that, due to the inherent irreversibility of the RIXS process, RIXS-CD does not require T breaking to be present, but reflects the change in unitary symmetries associated with magnetic ordering. Using the altermagnetic MnTe as a model system, we observe an azimuthal-angle dependent RIXS-CD signal in the magnon excitations. Our findings highlight the sensitivity of RIXS-CD to the relativistic symmetry in magnetic systems and its potential application as a probe of magnetic domains.