Robustness of the intrinsic anomalous Hall effect in Fe3GeTe2 to a uniaxial strain

Fe3GeTe2 (FGT), a ferromagnetic van der Waals topological nodal line semimetal, has recently been studied. Using first-principles calculations and symmetry analysis, we investigate the effect of a uniaxial tensile strain on the nodal line and the resultant intrinsic anomalous Hall effect (AHE). Our results reveal their robustness to the in-plane strain. Moreover, the intrinsic AHE remains robust even for artificial adjustment of the atomic positions introduced to break the crystalline symmetries of FGT. When spin-orbit coupling is absent, the nodal line degeneracy remains intact if the inversion symmetry or the twofold screw symmetry is maintained, which reveals that the nodal line may emerge much more easily than previously predicted. This strong robustness is surprising and disagrees with the previous experimental report [Wang et al., Adv. Mater. 32, 2004533 (2020)], which shows that a uniaxial strain of <1% of the in-plane lattice constant can double the anomalous Hall resistance. This discrepancy implies that the present understanding of the AHE in FGT is incomplete. The possible origins of this discrepancy are discussed.