Tunable Spin–Valley Locked Quantum Anomalous Hall Ferrovalley State in Néel Antiferromagnet Heterostructures

The quantum anomalous Hall (QAH) effect enables dissipationless transport. However, known QAH materials rarely combine ferrovalley behavior with spin–valley locking, and Néel antiferromagnets remain largely unexplored in QAH platforms. Here, we propose a spin–valley locked QAH ferrovalley state in a MnSe/Pt2HgSe3 heterostructure. Néel-ordered MnSe induces spin-polarized bands in Pt2HgSe3 via magnetic proximity, while spin–orbit coupling lifts valley degeneracy, yielding valley-dependent gaps and a sizable QAH gap of ∼40 meV at charge neutrality. Unlike conventional QAH systems, spin–valley locking is preserved in the conduction band, producing a distinct topological phase. Chemical-potential tuning drives transitions to spin-polarized anomalous valley Hall and anomalous Hall states with opposite spin–valley responses. An out-of-plane electric field reverses the Berry curvature distribution between valleys, while the Chern number and spin–valley texture are strongly coupled to the Néel vector, establishing a tunable antiferromagnetic topological-valleytronic platform.