Topological Hall-like effect signal in the La_0.67Sr_0.33MnO₃/Tb₂Ti₂O₇ heterojunction

The Dzyaloshinskii‒Moriya interaction (DMI) at the interface of nonferromagnetic/ferromagnetic heterostructure films can induce the formation of chiral magnetic structures such as skyrmions, leading to the topological Hall effect (THE). Here, we report the first growth of high-quality La_0.67Sr_0.33MnO₃/Tb₂Ti₂O₇ (LSMO/TTO) heterostructure films on single-crystal yttria-stabilized zirconia (111) substrates via laser molecular beam epitaxy. Electrical transport measurements reveal two key findings: (ⅰ) The anomalous Hall effect (AHE) of the LSMO/TTO heterostructure exhibits sign reversal within 50–100 K, and (ⅱ) a distinct hump signal emerges at low temperatures, differing from that of pure LSMO films. This hump signal weakens with increasing temperature, which is consistent with the characteristics of the THE. We propose that the THE-like signal originates from the LSMO lattice distortion induced by epitaxial growth on TTO, which breaks centrosymmetry and triggers DMI. Furthermore, the spin‒orbit coupling of Tb³⁺ 4f electrons likely generates interfacial spin currents, providing a driving force for the observed THE.