The quantum anomalous layer Hall effect (QALHE), characterized by the precise control of the quantum anomalous Hall effect on different layers due to spin-layer-chirality coupling in van der Waals (vdW) layered materials, is of great importance in both fundamental physics and nanodevices. In this work, through the analysis of a low-energy effective model for vdW heterobilayers under biaxial strain, we propose the QALHE in valleytronic materials for the first time. The spin-layer-locked edge states and Chern numbers in heterobilayers give rise to dissipationless currents localized in specific layers, realizing the long-sought QALHE in heterobilayers. The switch of the chirality of edge states and Chern numbers in heterobilayer systems can be achieved by applying a biaxial strain. We have validated this mechanism in a series of realistic valleytronic materials, including VSi2N4/VSiCN4 and RuCl2/FeCl2 heterobilayers. Our work reveals a new mechanism for achieving the QALHE with promising applications in spintronics and quantum layertronics.
Keywords: heterobilayer; layer degree of freedom; quantum anomalous layer Hall effect.