Anomalous Hall Effect in SrRuO₃/SrIrO₃ Heterostructures

Atomic-scale reconstructions at transition metal oxide interfaces can produce electronic and magnetic phases that are absent in the bulk constituents. Of particular interest are heterostructures of itinerant ferromagnets and materials with strong spin-orbit coupling (SOC), which can show interfacial reconstructions of electronic and magnetic properties. In this work, we examine the anomalous Hall effect (AHE) in transition metal oxide heterostructures composed of ultrathin SrRuO₃ and SrIrO₃. We find that, close to the sign-reversal temperature, the AHE can be modelled by two parallel channels producing Hall voltages of opposite sign. The different coercive fields allow control of the spin polarization of the two channels at fixed temperature, providing evidence of interlayer coupling. We propose that the strong SOC of the SrIrO₃ modifies the band structure and associated Berry curvature of the top SrRuO₃ layers near the SrRuO₃/SrIrO₃ interface.