Multiple Zeeman-type hidden spin splittings in PT-symmetric layered antiferromagnets

Centrosymmetric antiferromagnetic semiconductors, although abundant in nature, appear less favorable in spintronics owing to the lack of inherent spin polarization and magnetization. We unveil hidden Zeeman-type spin splitting in layered centrosymmetric antiferromagnets with asymmetric sublayer structures through first-principles simulations and symmetry analysis. Taking the bilayer counterpart of recently synthesized monolayer MnSe, we demonstrate that the degenerate states around specific k points spatially segregate on different sublayers forming PT-symmetric pairs. Furthermore, degenerate states exhibit uniform in-plane spin configurations with opposite orientations enforced by mirror symmetry. Bands are locally Zeeman split up to order of similar to 70meV. Strikingly, a tiny electric field of a few mV & Aring;-1 along the z direction breaks the double degeneracy forming additional Zeeman pairs. The design principle to obtain Zeeman-type splitting in centrosymmetric antiferromagnets established here expands the range of materials among which to look for spintronics.