Anisotropic transport properties and topological Hall effect in the annealed kagome antiferromagnet FeGe

Electron correlation often gives birth to various orders in quantum materials. Recently, a strongly correlated kagome antiferromagnet FeGe is discovered to undergo a charge density wave transition inside the A-type antiferromagnetic state, providing an opportunity to explore the interplay between charge order and magnetism. Here, we reported the observation of anisotropic resistivity and Hall effect, along with a topological Hall effect, in the annealed FeGe crystals. As the current flows along the ab-plane, the temperature dependence of ρ_ab exhibits a distinct resistivity loop related to a first-order transition at T_cdw. The applied magnetic fields do not alter T_cdw but can induce a spin-flop transition at H_sf. Consequently, a field-induced large topological Hall effect is observed in the canting antiferromagnetic (CAFM) state below T_cant, which is possibly attributed to the non-trivial spin texture during the spin-flop process. Whereas, as current is parallel to c-axis, both the field-induced transitions in ρ_c and χ_c disappear. Instead, the Hall resistivity in the annealed FeGe significantly exhibits a deviation from the linear field-dependent. These findings provide valuable insight into revealing the interplay among magnetism, charge order and topology in the kagome magnets.