Ferroelectric polarization control of spin states in Mn4N/PMN-PT heterostructures revealed by topological Hall effect
Topological Hall effect (THE) as one of spin-related effects originates from scalar spin chirality formed by non-coplanar spin structures, being a promising tool for probing the change of electron spin. Single-phase (022) Mn4N films with coplanar spin structures were prepared on unpoled ferroelectric [Pb(Mg1/3Nb2/3)O3]0.67-[PbTiO3]0.33 (PMN-PT) substrates. The transport properties of Mn4N/PMN-PT have been investigated. The decreased magnetization and anomalous resistivity imply that the spin states of Mn4N are influenced by ferroelectric polarization of the substrate. The observation of THE in the Mn4N/PMN-PT heterostructure strongly supports that the spin states of Mn4N are modified. After poling PMN-PT, the enhanced THE peak magnitude verifies that the spin states of Mn4N are tuned by ferroelectric polarization. This study provides a non-magnetic method for manipulation of spin states, which could avoid the external magnetic field perturbations.