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

Rehman, Majeed Ur; Xian, Lede · Nano Lett · 2026

basic_science · Level V

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Abstract

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/Pt<sub>2</sub>HgSe<sub>3</sub> heterostructure. Néel-ordered MnSe induces spin-polarized bands in Pt<sub>2</sub>HgSe<sub>3</sub> 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.