Chiral anomalous Hall effect in reentrant AuFe alloys

The Hall effect has been studied in a series of AuFe samples in the reentrant concentration range, as well as in part of the spin-glass range. An anomalous Hall contribution linked to the tilting of the local spins can be identified, confirming theoretical predictions of a different topological Hall term induced when chirality is present. This effect can be understood in terms of Aharonov-Bohm-like intrinsic current loops arising from successive scatterings by canted local spins. The experimental measurements indicate that the chiral signal persists, meaning scattering within the nanoscopic loops remains coherent, up to temperatures of the order of 150 K.