The role of the symmetry of spin fluctuation coherence on magnetotransport in Fe3Si thin films

We have observed an abrupt change at low temperatures in the intrinsic anomalous and planar Hall conductivities of nearly stoichiometric Fe3Si epitaxial thin films grown on GaAs(001). To describe this magnetotransport regime, we phenomenologically take into account the reduction in symmetry resulting from the onset of coherent spin fluctuations. Our theoretical approach can thus account for these different magnetotransport regimes in both the anomalous Hall effect and planar Hall effect as well as the impact on intrinsic magnetotransport of atomic disorder away from stoichiometry.