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

TL;DR

This study demonstrates that the intrinsic anomalous Hall effect in Fe3GeTe2 is highly robust against uniaxial strain and atomic position adjustments, challenging previous experimental findings and suggesting a need for further investigation.

Contribution

The paper provides first-principles calculations showing the robustness of the anomalous Hall effect in Fe3GeTe2 under strain and symmetry-breaking, revealing new insights into its topological properties.

Findings

Intrinsic AHE remains robust under in-plane uniaxial strain.

Nodal line degeneracy persists without spin-orbit coupling if certain symmetries are maintained.

Discrepancy with previous experiments suggests incomplete understanding of AHE in FGT.

Abstract

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 the spin-orbit coupling is absent, the nodal line degeneracy remains intact as long as the inversion symmetry or the two-fold screw symmetry is maintained, which reveal that the nodal line may emerge much more easily than previously predicted. This strong robustness is surprising and disagrees with the previous experimental report [Y. Wang et al., Adv. Mater. 32, 2004533 (2020)], which reports that a uniaxial strain of less than 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.