Spin-Chirality-Driven Quantum Anomalous and Quantum Topological Hall Effects in Chiral Magnets

The quantum anomalous Hall effect (QAHE) is a highlyresearchedtopic in condensed matter physics due to its ability to enable dissipationlesstransport. Previous studies have mainly focused on the ferromagneticQAHE, which arises from the combination of collinear ferromagnetismand two-dimensional (2D) Z (2) topologicalinsulator phases. In our study, we demonstrate the emergence of thespin-chirality-driven QAHE and the quantum topological Hall effect(QTHE) by sandwiching a 2D Z (2) topologicalinsulator between two chiral kagome antiferromagnetic single-layerssynthesized experimentally. The QAHE is surprisingly realized withfully compensated noncollinear antiferromagnetism in contrast to conventionalcollinear ferromagnetism. The Chern number can be regulated periodicallywith the interplay between vector- and scalar-spin chiralities, andthe QAHE emerges even without spin-orbit coupling, indicatingthe rare QTHE. Our findings open a new avenue for realizing antiferromagneticquantum spintronics based on the unconventional mechanisms from chiralspin textures.