Interface-Induced Anomalous Hall Conductivity in a Confined Metal

The mature silicon technological platform is actively explored for spintronic applications. Metal silicides are an integral part of the Si technology used as interconnects, gate electrodes, and diffusion barriers; their epitaxial integration with Si results in premier contacts. Recent studies highlight the exceptional role of electronic discontinuities at interfaces in the spin-dependent transport properties. Here, we report a new type of Hall conductivity driven by sharp interfaces of Eu silicide, an antiferromagnetic metal, sandwiched between two insulators - Si and SiOx. Quasi ballistic transport probes spin-orbit coupling at the interfaces, in particular, charge-spin interconversion. Transverse magnetic field results in anomalous Hall effect signals of an unusual line shape. The interplay between opposite-sign signals from the two interfaces allows efficient control over the magnitude and sign of the overall effect. Selective engineering of interfaces singles out a particular spin signal. The two-channel nature of the effect and its high tunability offer new functional possibilities for future spintronic devices.