Ferroelectric-Polarization-Control of Metallicity and Magnetism in SrIrO₃

We report nonvolatile ferroelectric field effect modulation of the metallicity and magnetotransport properties of ultrathin SrIrO₃ films. We have fabricated high quality epitaxial heterostructures composed of ferroelectric PbZr_0.2Ti_0.8O₃ (PZT) gate and 4-5 unit cell (uc) SrIrO₃ channel. Switching the polarization of PZT induces nonvolatile modulation of SrIrO₃ resistance. The 5 uc channel exhibits metallic behavior in both polarization states. The resistance decreases with decreasing temperature at high temperatures, which transitions to a ln(T) behavior below a transition temperature. Modeling the magnetoresistance in the 2D regime using the weak localization/antilocalization model reveals the modulation of inelastic scattering time and spin-orbit scattering time via PZT polarization. The 4 uc SrIrO₃ channel exhibits metallic (insulating) behavior in the polarization up (down) state. Close to the metal-insulator transition, the sample exhibits anomalous Hall and topological Hall effects, suggesting the emergence of magnetism. Our study points to a new route for interface engineering of quantum phases in iridates.