Valley Dependent Quantum Anomalous Hall Property in Ferrimagnetic Honeycomb Lattice

The valley-polarized quantum anomalous Hall effect (VP-QAHE), which combines valleytronics and topology in one material, is of significant fundamental and practical importance in condensed-matter physics and materials science. In previous model studies, VP-QAHE occurs under strong Rashba spin-orbit coupling (SOC), which is an extrinsic effect. We propose a different mechanism of VP-QAHE by developing a general picture of valley dependent band inversion in honeycomb lattice. Using first-principles calculation, this mechanism is further demonstrated in the Co-In thin film on a Si(111) surface. This system is equivalent to a ferrimagnetic honeycomb lattice. The underlying physical mechanism is generally applicable, opening a new avenue for exploration of substrate supported VP-QAHE.