Quantum Anomalous Layer Hall Effect in Realistic van der Waals Heterobilayers.

Tian, Yuping; Kong, Xiangru; Jiang, Cui; Zhang, Huai-Jin; Gong, Wei-Jiang · Nano Lett · 2025

basic_science · Level V

Where this comes from

Abstract

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 VSi<sub>2</sub>N<sub>4</sub>/VSiCN<sub>4</sub> and RuCl<sub>2</sub>/FeCl<sub>2</sub> heterobilayers. Our work reveals a new mechanism for achieving the QALHE with promising applications in spintronics and quantum layertronics.