Spin-orbit coupling in antiferromagentic MnTe*

We show that the spin-orbit coupling (SOC) in α-MnTe impacts the transport behavior by generating an anisotropic valence-band splitting, resulting in four spin-polarized pockets near Gamma. A minimal k-dot-p model is constructed to capture this splitting by group theory analysis, a tight-binding model and ab initio calculations. The model is shown to describe the rotation symmetry of the zero-field planer Hall e ect (PHE). The PHE percentage is determined by the SOC induced band shape, and is quantitatively estimated to be 25% ∼ 31% for an ideal thin film with a single antiferromagnetic domain. The k-dot-p Hamiltonian given by this research is not only effective, but also minimal. The quartic spin-orbit coupling terms in the model is necessary, in the absence of which, the extra C4T symmetry rules out any Hall effect. The predicted value of PHE percentage is an order of magnitude greater than previous experimental observations, suggesting a vast space to optimize the material for device applications.