Interface-to-Surface Transition Induced Topological Hall Effect in 2-Dimensional SrRuO3 Integrated on Silicon.

The topological Hall effect (THE), a transport signature emerging from chiral spin textures induced by structural symmetry breaking and the Dzyaloshinskii-Moriya interaction (DMI), represents a rich frontier in condensed matter physics with promising applications in spintronic devices. To enhance the DMI and thereby induce THE in SrRuO3 (SRO), we introduce a structural-symmetry-breaking strategy that disrupts the Ru-O termination at the rigid substrate interface. This disruption triggers a transition from a rigid epitaxial interface to a freestanding membrane with unsaturated surface bonds, resulting in asymmetric surface terminations (Sr-O on top and Ru-O at the bottom). Unlike its rigid counterpart, which shows no detectable THE, the freestanding SRO exhibits a pronounced THE signal, persisting up to 100 K while preserving high crystallinity and electronic coherence. The ability to generate robust THE in transferable oxide membranes has direct implications for next-generation spintronics, offering compelling prospects for creating low-power magnetic memory and logic devices based on chiral spin textures.