Anomalous Hall effect due to magnetic chirality in the pyrochlore lattice
Résumé
We calculate the intrinsic Hall conductivity of conductions electrons coupled to a pyrochlore lattice of localized moments. In the presence of anisotropy the localized moments may order in a non-coplanar chiral structure, which can be at the origin of an intrinsic Hall effect. The sign and the value of the Hall conductance depend on the band filling factor and the local exchange coupling. Application of an external magnetic field induces a change in the magnetic structure of the localized spins which results in a change of the Hall conductance. In this framework, the temperature dependence of the Hall conductance may exhibit a nonmonotonical behavior. The results are in a qualitative agreement with experimental results on Mo pyrochlores.