Tunable Anomalous Hall Effect in Broken–Symmetry Integrated Perovskite/Brownmillerite Superlattices

Abstract The anomalous Hall effect (AHE), a hallmark of broken time–reversal symmetry, serves as a powerful tool for probing magnetic states and elucidating complex spin–orbit interactions in transition metal oxides. It is reported here that the emergence of AHE signals and interfacial ferromagnetism is directly observed from broken–symmetry integrated perovskite PrCoO₃ and brownmillerite SrCoO_2.5 superlattices. Through the strategic combinations of these two complex oxide systems onto the substrates with tailored lattice parameters, squared AHE hysteresis loops with perpendicular magnetic anisotropy are found under compressive strain in the optimized superlattices, and the magnitude of the loops is more than three times greater compared to those under tensile strain. The manifestation of AHE in these superlattices is attributed to an extrinsic mechanism involving spin–polarized scattering of charge carriers, with the mismatched perovskite/brownmillerite interfaces acting as the primary scattering centers. These discoveries suggest a promising avenue for the development of artificial materials with controllable AHE properties.