Symmetry-engineered and electrically tunable in-plane anomalous Hall effect in oxide heterostructures

Anomalous Hall effect (AHE) has long served as a cornerstone for uncovering low-dissipation quantum phenomena and powering Hall-based functionalities, yet its tunability and device application are both constrained by the orthogonal relationship among electric field, Hall current, and out-of-plane magnetization in thin film geometry. The recently emerged in-plane anomalous Hall effect (IP-AHE), a transverse Hall response driven by in-plane magnetization, promises to unlock Hall readout of planar magnetic orders and spin textures. However, in sharp contrast to conventional AHE, experimentally accessible and effective control strategies for IP-AHE remain largely undeveloped, impeding its transition from phenomenological observation to device implementation. Here we establish a symmetry-engineered, electrically tunable IP-AHE in epitaxial CaRuO3/La2/3Ca1/3MnO3/CaRuO3 heterostructures grown on NdGaO3(110). By exploiting CaRuO3-buffer-controlled mirror-symmetry breaking in the ferromagnetic La2/3Ca1/3MnO3 layer, we achieve a robust IP-AHE that faithfully mirrors square-shaped ferromagnetic hysteresis, providing a direct Hall readout of in-plane magnetization reversal. Ionic liquid gating further enables dynamic reconfiguration of the symmetry breaking, achieving wide-range electrical modulation and fully reversible ON/OFF switching of IP-AHE. This highly tunable IP-AHE platform offers a symmetry-based probe of emergent low-dimensional magnetism and facilitates the development of programmable Hall functionalities in planar device geometries.