Chiral Altermagnon in MnTe
Daniel Jost, Resham B. Regmi, Eder G. Lomeli, Samuel Sahel-Schackis, Monika Scheufele, Marcel Neuhaus, Rachel Nickel, Flora Yakhou, Kurt Kummer, Nicholas Brookes, Lingjia Shen, Georgi L. Dakovski, Nirmal J. Ghimire, Stephan Geprägs, Matthias F. Kling
Published: 2025/1/29
Abstract
Altermagnetism has surfaced as a novel magnetic phase, bridging the properties of ferro- and anti-ferromagnetism. The momentum-dependent spin-splitting observed in these materials reflects their unique symmetry characteristics, which also establish the conditions for chiral magnons to emerge. Here we provide the first direct experimental evidence for a chiral magnon in the altermagnetic candidate MnTe revealed by circular-dichroism resonant inelastic X-ray scattering (CD-RIXS). This mode which we term chiral altermagnon exhibits a distinct momentum dependence of its spin polarization consistent with the proposed altermagnetic $g-$wave symmetry of MnTe. Our polarization-resolved results corroborate the existence of a new class of magnetic excitations, demonstrating how altermagnetic order shapes spin dynamics and paves the way for advances in spintronic and quantum technologies.