Inner-edge states in silicene nanoribbons and related applications to novel device design

Abstract

We study the quantum transport in hybrid silicene nanoribbons in the presence of a spatially alternative electric field. We found that valley resolved inner-edge states can be obtained in zigzag nanoribbons with opposite electric fields applied in the upper and lower half-nanoribbons, and pure valley current is obtained. A dissipationless transistor is designed based on the inner-edge states. It is found that the inner-edge states are not robust, and defects on the interface between the upper and lower half-nanoribbons can change the conductance to zero. To improve the performance of the device, we consider a region without electric field between two regions with opposite electric fields. Electrons is not confined at the interface of the upper and lower half-nanoribbons, and they can transport in the region without electric field. Defects can also affect the conductance, but the conductance can not be changed to zero easily. Armchair nanoribbons are also considered in this study to design a dissipationless transistor, and the difference is that we do not consider the degree of freedom valley in the device based armchair ribbons. Our findings open the possibility of the dissipationless transistor design based on inner-edge states in silicene nanoribbons.