Observation of Unidirectional Anisotropic Magnetoresistance in Altermagnetic MnTe (0001) Films

ABSTRACT Altermagnetism has recently attracted significant attention as a novel magnetic phase, offering a promising platform for next‐generation spintronics. For example, manganese telluride (MnTe) is one of typical materials due to its pronounced anisotropic transport properties. We report the discovery of unidirectional anisotropic magnetoresistance (UAMR) effect in epitaxially grown MnTe (0001) thin films—a phenomenon previously unresolved in earlier research. The phase and amplitude of the UAMR exhibit hysteresis behavior during counterclockwise and clockwise senses of the initial orientation of the magnetic field in the basal plane, with the amplitude variation reaching up to 200%. Our findings not only provide deeper insight into the coupling between transport properties and magnetic order in altermagnets, but also highlight the potential of UAMR in enabling highly robust magnetic sensing and non‐volatile memory technologies.