Spin-resolved ARPES study on altermagnet candidates RuO2 and MnTe

Spintronics aims to control electron spin in space, momentum, and energy, requiring materials that combine ferromagnetic traits (easy information writing/reading) with antiferromagnetic stability, high-density storage, and ultrafast spin dynamics. Recent studies highlight unconventional magnets, such as spin-splitting antiferromagnets (including "altermagnets") and anomalous Hall antiferromagnets, which exhibit ferromagnetic-like properties due to spin group symmetries. These materials merge the advantages of ferromagnets and antiferromagnets, potentially revolutionizing spintronics. RuO2 and MnTe are two metallic candidates hosting unconventional antiferromagnetism. RuO2 shows anomalous Hall effect and spin-splitting torque, likely due to d-wave altermagnetic bands, though recent studies suggest it may be nonmagnetic. Its electronic structure and spin texture remain unclear, necessitating spin-resolved ARPES (SARPES) for clarification. MnTe is a spin-split antiferromagnet, but its spin texture is largely unexplored. SARPES is crucial to understand its spin splitting behavior. To probe the spin splitting and 3D spin textures of RuO2 and MnTe, we propose SARPES measurements at beamline LOREA of ALBA.