Altermagnetism is a newly identified fundamental class of magnetism with vanishing net magnetization and time-reversal symmetry broken electronic structure. Probing the unusual electronic structure with nonrelativistic spin splitting would be a direct experimental verification of an altermagnetic phase. By combining high-quality film growth and in situ angle-resolved photoemission spectroscopy, we report the electronic structure of an altermagnetic candidate, α-MnTe. Temperature-dependent study reveals the lifting of Kramers degeneracy accompanied by a magnetic phase transition at T_{N}=267 K with spin splitting of up to 370 meV, providing direct spectroscopic evidence for altermagnetism in MnTe.

Center for Artificial Low Dimensional Electronic Systems Institute for Basic Science Pohang 37673 Korea

Center for Correlated Electron Systems Institute for Basic Science Seoul 08826 Korea

Department of Physics and Astronomy Seoul National University Seoul 08826 Korea

Department of Physics Chungnam National University Daejeon 34134 Korea

Department of Physics Pohang University of Science and Technology Pohang 37673 Republic of Korea

Institut für Physik Johannes Gutenberg Universität Mainz D 55099 Mainz Germany

Institute of Physics Czech Academy of Sciences Cukrovarnická 10 162 00 Praha 6 Czech Republic

Pohang Accelerator Laboratory Pohang University of Science and Technology Pohang 37673 Korea

The Research Institute of Basic Sciences Seoul National University Seoul 08826 Korea

References provided by Crossref.org

Nanoscale imaging and control of altermagnetism in MnTe

Anisotropic magnetoresistance in altermagnetic MnTe

Observation of a spontaneous anomalous Hall response in the Mn5Si3 d-wave altermagnet candidate

Direct observation of altermagnetic band splitting in CrSb thin films