Altermagnetic ordering of the electronic density of states in MnTe.
Since 2020, a new branch of magnetic materials, altermagnets, has been theoretically identified, in addition to the conventional ferromagnets and antiferromagnets. The exclusively distinct spin-symmetry characteristics of altermagnets are the opposite-spin sublattices connected by a real-space rotation, but not connected by a translation or inversion. Such symmetry has unconventional physical consequences.
Our colleague K. Uhlirova successfully prepared high-quality MnTe single crystals, a previously proposed candidate for altermagnetism. This work is the first experimental evidence of the unconventional nature and existence of altermagnets. The authors confirm the presence of lifted Kramers spin degeneracy (LKSD) without net magnetization or inversion symmetry braking using angle-resolved photoemission spectroscopy (ARPES) and show the spin-resolved ARPES supported by ab initio electronic-structure calculations. Consistently with the strong LKSD, spin-resolved ARPES shows the alternating sign of the spin-polarization component along the Néel vector.
