Charge-mediated magnetoelectricity: from ferroelectric field effect to charge-ordering ferroelectrics

Magnetoelectricity is an emerging topic and a frontier issue of the field of ferroelectricity. Multiferroics containing more than one ferroic order is an ideal system to pursuit intrinsic and robust magnetoelectric coupling, which holds rich physics and great potential applications. As a branch of the correlated electron family, multiferroic also has multiple degrees of freedom, including the charge, spin, orbital, and lattice. Among them, the charge degree of freedom has been mostly overlooked in the past researches and actually it may play an important role in magnetoelectricity. In this topical review, the charge-mediated magnetoelectricity is introduced, including the ferroelectric field effect in heterostructures and the charge ordering in single-phase multiferroics. The physical mechanisms will be revealed, together with several examples we given in recent years. We hope that this topical review can provide a reference for the researches in this vigorous filed.