  We report interfacial transport properties in in-situ grown orthorhombic
perovskite oxide heterostructures consisting of an antiferromagnetic insulator
DyFeO$_3$ and a paramagnetic conductor CaRuO$_3$. We observe Hall effect with a
step-like increase amounting to an effective magnetic field of 30 T at 20 K. We
provide a plausible explanation in the context of topological Hall effect
originating from a non-coplanar spin texture and resultant emergent field in
DyFeO$_3$ associated with the scalar spin chirality. Our results demonstrate
that the proximity effect of the emergent field at heterointerfaces is a
universal physical phenomenon, while it has been reported originally in a
heterointerface composed of pyrochlore oxides. This will greatly expand the
choice of materials to the heterointerfaces for the research in emergent
transport phenomena, which has been limited to single compounds with both
metallic properties and special spin textures. Additionally, this will pave the
way for possible device application of the emergent field by designing and
combining perovskite oxides with versatile functionalities such as
multiferroicity.
