Anomalous Hall effect in Fe₃GeTe₂: Microscopic mechanism and uniaxial strain effect

Among the several 2D magnetic van der Waals materials, Fe₃GeTe₂ (FGT) has garnered particular interest as a topological ferromagnetic semimetal. The presence of ferromagnetism with topological physics renders this material a platform for interesting phenomena, such as the enormous Berry phase effects. Here we discuss the uniaxial strain effect on the topological properties of FGT and the microscopic mechanism of the anomalous Hall effect (AHE). This study shows the stability of the AHE and the evidence of a nodal line of FGT under uniaxial strains using first-principle calculations and model analysis with symmetries. In addition, the topological origin of the intrinsic AHE is demonstrated that the orbital hybridization is responsible for the substantial Berry curvature near Γ point, which is large enough to compare with the previously reported K point contribution. It has important implications for understanding topological ferromagnetic materials and the discovery of magnetic materials exhibiting stronger topological features. Utilizing such topological stability, a quantum device that is resistant to external noise and information loss can be implemented, which is the subject of intensive global research.