Engineering Weyl Nodes in Ferrimagnetic Li₂Fe₃S₄

In recent years, Weyl semimetals (WSM) have been intensely studied in view of their electronic transport properties that appear to be interesting for technological applications. These properties rest on low-energy quasi-particle excitations of electrons that mimic features of mass-less Weyl fermions. By means of density-functional calculations, we investigate Li₂Fe₃S₄ with monoclinic structure and nonsymmorphic symmetry. The magnetic ground state of this compound is found to be ferrimagnetic with a total magnetic moment of about 8 μB per unit cell. Our calculations suggest four pairs of Weyl nodes within an energy range of 40 meV around the Fermi level. Considering different magnetization directions, the positions of these nodes are significantly modified. Thus, Li₂Fe₃S₄ is a promising candidate for the tuning of WSM-related transport properties by rotating its direction of magnetization.