Sign Switching of Spin Hall Magnetoresistance in all Oxide Heterostructures via Atomistic Interface Engineering

ABSTRACT The sign switching of spin Hall magnetoresistance (SMR) is pivotal to enable the binary logic operation for the next‐generation spintronics applications. While various mechanisms have been proposed to understand the origin of both the positive and negative SMR, a search for the control parameter to switch the sign of SMR has remained elusive. In this study, switchable SMR is realized in all oxide heterostructures and superlattices via the atomistic controlled interface engineering. Present results demonstrate the thickness‐mediated switching of the SMR in SrRuO 3 /CaIrO 3 heterostructures from negative to positive due to the competing contributions from the spin‐to‐charge interconversion at both the interface and the bulk of the heterostructure. The first principal density functional calculations are in agreement with the experimental results, revealing enhanced spin Hall conductivity in SrRuO 3 /CaIrO 3 heterostructures and confirming the CaIrO 3 thickness‐controlled variation in SMR driven by the competition between the bulk spin Hall effect and interfacial spin‐orbit coupling. Varying the SrRuO 3 layer thickness leads to a modulation of the magnetic anisotropy, which results in the complete suppression of SMR. The present study offers a pathway for designing reconfigurable spintronic devices, enabling precise control over spin current flow and resistance states for advanced memory and logic applications.