Giant electroresistance and tunable magnetoelectricity in a multiferroic junction

First-principles density functional calculations show that the SrRuO3/PbTiO3/SrRuO3 multiferroic junction with asymmetric (RuO2/PbO and TiO2/SrO) interfaces has a large ferroelectric depolarizing field, whose switching changes the interface transmission probabilities for tunneling electrons, leading to electroresistance modulation by over two orders of magnitude. The switching further affects the interface spin density, naturally driving magnetoresistance as well as modulated spin-dependent in-plane resistivity, which may be exploited in field-effect devices.