Paper detail

Nature of Valance Band Splitting on Multilayer MoS2

Understanding the origin of splitting of valance band is important since it governs the unique spin and valley physics in few-layer MoS2. With first principle methods, we explore the effects of spin-orbit coupling and layer's coupling on few-layer MoS2. It is found that intra-layer spin-orbit coupling has a major contribution to the splitting of valance band at K. In double-layer MoS2, the layer's coupling results in the widening of energy gap of splitted states induced by intra-layer spin-orbit coupling. The valance band splitting of bulk MoS_2 in K can follow this model. We also find the effect of inter-layer spin-orbit coupling in triple-layer MoS2. In addition, the inter-layer spin-orbit coupling is found to become to be stronger under the pressure and results in the decrease of main energy gap in the splitting valance bands at K.