Magnetic transition and spin-polarized two-dimensional electron gas controlled by polarization switching in strained CaMnO3/BaTiO3 slabs

Ab4pt0exinitio calculations show the presence of a strong magnetoelectric interfacial coupling in a CaMnO₃ ultrathin film grown on a strained BaTiO₃ ferroelectric film. This heterostructure presents a polarization driven magnetic transition from a G-type to an A-type antiferromagnetic structure. Together with this magnetic transition we find a metallic behavior at the interface between these two insulators, where the charge character of the carriers can be tuned from electrons to holes by switching the electric polarization direction of the ferroelectric film. Besides, the electron gas is spin polarized while the hole gas is not.