Stacking-dependent anomalous valley Hall effect in bilayer Janus VSCl

H-phase hexagonal two-dimensional lattices have been extensively studied in the field of valleytronics. In contrast, their counterparts in the T phase have received relatively less attention due to the presence of inversion symmetry, which limits the potential for generating an anomalous valley Hall effect (AVHE). However, the Janus and bilayer stacking structures provide additional prospects to discover extra candidates. Herein, we employed first-principles calculations to predict the stacking-dependent AVHE in bilayer Janus VSCl. Owing to the intrinsic net magnetic moment, the valleys of the monolayer Janus VSCl are spontaneously polarized by out-of-plane magnetization, obviating the need for the external magnetic substrate. This valley polarization can be maintained through specific stacking configurations, allowing electrons with identical spins but different valley indices to flow toward the same side, which results in a significant AVHE and the emergence of a spin current. Notably, we found that interlayer coupling can selectively enhance or diminish the Berry curvatures of the two nonequivalent valleys, even without any external strain. Additionally, the results are effectively explicable through the analysis of our proposed model. In this paper, we present a promising material and put forth ideas for uncovering valleytronic candidates.