Anomalous Hall Effect in 5d/5d SrTaO3/SrIrO3 Superlattices Driven by Ferromagnetism and Spin-Orbit Coupling

The observation of the anomalous Hall effect (AHE) in 5d perovskite oxides has been challenging due to their lack or weak ferromagnetic order, which is necessary for breaking time-reversal symmetry. Here, we present compelling evidence of ferromagnetism and consequent AHE in a series of carefully designed and fabricated 5d/5d SrTaO3/SrIrO3 (STO/SIO) superlattices. The coexistence of Ta5+ and Ta4+ chemical states induces ferromagnetism in the STO layer, while the interfacial magnetic proximity effect further enhances it in the SIO layer, resulting in both ferromagnetism and AHE within the STO/SIO superlattice. Additionally, the strong spin-orbit coupling between Ta and Ir elements positively contributes to enhancing the AHE. This work offers an alternative approach for designing artificial materials with AHE and holds potential for advancing spintronics.