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MA: Fachverband Magnetismus
MA 21: Phd Focus Session: Altermagnets: Foundations and Experimental Evidence
MA 21.4: Talk
Wednesday, March 20, 2024, 10:45–11:00, H 1058
Imaging the altermagnetic domain structure in MnTe — •Oliver Amin1, Alfred Dal Din1, Evangelos Golias2, Yuran Niu2, Alexei Zakharov2, Sarnjeet Dhesi3, Tomas Jungwirth4, Kevin Edmonds1, and Peter Wadley1 — 1University of Nottingham, Nottingham, UK — 2MAX IV, Lund, Sweden — 3Diamond Light Source, Harwell, UK — 4Institute of Physics, Prague, Czech Republic
Altermagnets are collinear, fully compensated magnetic systems, in which the sublattice magnetisations are connected through a rotation symmetry combined with time inversion. This reduced symmetry arises from the asymmetric local environments surrounding the magnetic sites and, as a result, the electronic band structure exhibits large momentum-dependent spin splitting that allows for time-inversion broken phenomena, unique in a compensated magnetic material. Understanding the domain structure of altermagnetic materials is crucial for elucidating the connection between the orientation of the compensated moment, called the Néel vector, and the emergence of time symmetry breaking phenomena. Here we show, in thin film altermagnetic candidate material, α-MnTe, that X-ray magnetic circular dichroism in combination with photoemission electron microscopy (XMCD-PEEM) can be used to spatially resolve domain structure related to the altermagnetic symmetries. We confirm that the orientation of the Néel domains is essential in determining the sign of the XMCD signal and uniquely defines a map of the local sublattice magnetisation direction.
Keywords: altermagnet; imaging; spintronics; MnTe