Half-magnetization plateau and the origin of threefold symmetry breaking in an electrically-switchable triangular antiferromagnet
Abstract
We perform high-field magnetization measurements on the triangular lattice antiferromagnet Fe1/3NbS2. We observe a plateau in the magnetization centered at approximately half the saturation magnetization over a wide range of temperature and magnetic field. From density functional theory calculations, we determine a likely set of magnetic exchange constants. Incorporating these constants into a minimal Hamiltonian model of our material, we find that the plateau and of the Z3 symmetry breaking ground state both arise from interplane and intraplane antiferromagnetic interactions acting in competition. These findings are pertinent to the magneto-electric properties of Fe1/3NbS2, which allow electrical switching of antiferromagnetic textures at relatively low current densities.