Spin Imbalanced anomalous Hall effect and Magnus Hall effect of Bilayer Silicene

Abstract

Silicene have been proposed to host multiple topological phases depending on the environmental parameters such as gated voltage and proximity induced exchange field. Two typical topological phase are quantum spin Hall phase and quantum anomalous Hall phase. We found that in the presence of antiferromagnetic exchange field and (or) gated voltage, the bilayer silicene host a topological phase that the Chern numbers of the two spin are different in both sign and magnitude, .i.e the anomalous Hall effects of the two spins are imbalanced. The topological phase is generated by triple band inversion that changes the Chern number of the upper and lower bands by $\pm3$. The phase host large anomalous spin Hall respondence. Meanwhile, because of the large trigonal warping in bilayer silicene near to the triple band inversion regime, the Magnus Hall effect is large. This finding enriches the topological systems of bilayer silicene as candidate for spintronic devices.