Dr. K. Uhlirova successfully prepared high-quality MnTe single crystals, a previously proposed candidate for altermagnetism. The single crystals were a cornerstone for successful spin-resolved angle-resolved photoemission spectroscopy, confirming lifted Kramer’s spin degeneracy in this material.
In this paper, the authors confirm the presence of lifted Kramers spin degeneracy (LKSD) without net magnetization or inversion-symmetry breaking using photoemission spectroscopy and ab initio calculations. They identify two distinct, unconventional mechanisms of LKSD induced by the altermagnetic phase of centrosymmetric MnTe, which has no net magnetization. The study reveals that altermagnetic LKSD could significantly impact magnetism, motivating further exploration and exploitation of this unconventional magnetic phase across a broad range of materials, including insulators, semiconductors, metals, and superconductors.