Strong multiferroicity and giant magnetoelectric effect in \((Insulator)/(LaMnO_3)_n/(SrMnO_3)_n/(Insulator)\) heterostructure

Abstract

We demonstrate that manganite heterostructures of the form \((Insulator)/(LaMnO_3)_n/(SrMnO_3)_n/(Insulator)\) show strong multiferroicity with magnetic ordering being induced by ferroelectric charge ordering. Ferroelectric polarization is produced by charges leaking from \(LaMnO_3\) side to the \(SrMnO_3\) side on account of the effective nearest-neighbor repulsion of electrons resulting from electron-phonon interaction. The origin of the ferromagnetism is due to double exchange when a particle virtually hops to its unoccupied neighboring site and back. Furthermore, we also demonstrate that a striking giant magnetoelectric effect occurs due to the strong coupling between the charge and spin orderings.