Disorder driven crossover between anomalous Hall regimes in Fe3GaTe2

Abstract

The large anomalous Hall conductivity (AHC) of the Fe3(Ge, Ga)Te2 compounds has attracted considerable attention. Here, we expose the intrinsic nature of the AHC in Fe3GaTe2 crystals characterized by high conductivities, which show disorder-independent AHC with a pronounced value sigma xc y approximate to 420 Q-1cm-1. In the low-conductivity regime, we observe the scaling relation Qxy oc axx1.6, which crosses over to Qxy sigma xc y as axx increases. Disorder in low-conductivity crystals is confirmed by the broadening of a first-order transition between ferromagnetism and the ferrimagnetic ground state. Through density functional theory (DFT) calculations, we reveal that the dominant sources of Berry curvature are located a few hundred meV below the Fermi energy around the P point. Therefore, Fe3GaTe2 clearly exposes the disorder-induced crossover among distinct AHC regimes, previously inferred from measurements on different ferromagnets located on either side of the crossover region.

The large anomalous Hall conductivity (AHC) of the Fe3(Ge, Ga)Te2 compounds has attracted considerable attention. Here, we expose the intrinsic nature of the AHC in Fe3GaTe2 crystals characterized by high conductivities, which show disorder-independent AHC with a pronounced value σcxy ≈ 420 −1cm−1. In the low-conductivity regime, we observe the scaling relation σxy ∝ σ1.6 xx , which crosses over to σxy σc xy as σxx increases. Disorder in low-conductivity crystals is confirmed by the broadening of a first-order transition between ferromagnetism and the ferrimagnetic ground state. Through density functional theory (DFT) calculations, we reveal that the dominant sources of Berry curvature are located a few hundred meV below the Fermi energy around the point. Therefore, Fe3GaTe2 clearly exposes the disorder-induced crossover among distinct AHC regimes, previously inferred from measurements on different ferromagnets located on either side of the crossover region.