2025-11-14 早稲田大学
図1. 三種類の共線磁性体の概念図。強磁性体（左）はスピンの向きが揃った状態、反強磁性体（中央）はスピンの向きが相殺する状態。反強磁性体の2つの副格子は空間反転(P)や並進(t)で結びつく。第三の磁性体と呼ばれる交替磁性体（右）もスピンが相殺した状態だが、副格子を結びつけるには空間回転を伴う操作（図の場合は90度回転C4と並進t）を行う必要がある。
＜関連情報＞
- https://www.waseda.jp/inst/research/news/82776
- https://journals.aps.org/prl/abstract/10.1103/512v-n5f9
共鳴非弾性X線散乱における円二色性：MnTeの交代磁性ドメインの探究 Circular Dichroism in Resonant Inelastic X-Ray Scattering: Probing Altermagnetic Domains in MnTe
D. Takegami, T. Aoyama, T. Okauchi, T. Yamaguchi, S. Tippireddy, S. Agrestini, M. García-Fernández, T. Mizokawa, K. Ohgushi et al.
Physical Review Letters Published: 6 November, 2025
DOI: https://doi.org/10.1103/512v-n5f9
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.
