Unravelling the origin of the topological Hall effect in Fe3Ga4

Notions of topology in condensed matter has received notable interest in the last few years, especially in the way topologically non-trivial magnetic structures can influence charge transport. Recently, Fe3Ga4 has been found to possess the topological Hall effect (THE), but it is unclear if the effect has its origins in an amplitude modulated spin-density wave or a spin-helix. Here we propose to use polarised small angle neutron scattering to decisively determine the ground state spin-configuration of the Fe magnetic sublattice. The unambiguous determination of ground state magnetic structure of Fe3Ga4 is imperative for identification the origin of the THE.