Observation of van Hove Singularities in Twisted Silicene Multilayers

Interlayer interactions perturb the electronic structure of twodimensional

materials and lead to new physical phenomena, such as van Hove

singularities and Hofstadter’s butterfly pattern. Silicene, the recently

discovered two-dimensional form of silicon, is quite unique, in that silicon

atoms adopt competing sp2 and sp3 hybridization states leading to a lowbuckled

structure promising relatively strong interlayer interaction. In

multilayer silicene, the stacking order provides an important yet rarely

explored degree of freedom for tuning its electronic structures through

manipulating interlayer coupling. Here, we report the emergence of van Hove

singularities in the multilayer silicene created by an interlayer rotation. We

demonstrate that even a large-angle rotation (>20°) between stacked silicene

layers can generate a Moiré pattern and van Hove singularities due to the

strong interlayer coupling in multilayer silicene. Our study suggests an

intriguing method for expanding the tunability of the electronic structure for

electronic applications in this two-dimensional material.