Spin-orbit unrelated spin splitting in real antiferromagnets

Our recent studies (Phys. Rev. B 102, 014422 (2020); Phys. Rev. Materials 5, 014409​ (2021)) point out an unconventional momentum-dependent spin splitting (SS) in certain antiferromagnets, present even without spin-orbit coupling (SOC) or inversion symmetry breaking. We developed the theory of magnetic and space symmetry conditions enabling different spin splitting types (SST's). Using such "Design Principles" to guide DFT material search points to specific (but not all) antiferromagnetic compounds manifesting such spin splitting. First principles calculations provide specific predictions of spin splitting vs. momentum and spin texture, awaiting experimental testing. The idea of turning on or off the spin splitting via enabling or removing such symmetry conditions (e.g via specific atomic distortions) has been examined for the prototype case of NiO than in its undistorted AFM state lacks SS. This reveals the significant role of the nonmagnetic ligands in mediating indirect magnetic interactions (such as superexchange). The proposed alternative mechanism to spin splitting opens possibilities for discovery of novel light-atom antiferromagnets that promote effects previously tested for SOC systems such as spin-current generation and current-driven spin excitations.