Abstract
We study the valley-dependent electron transport in a four-terminal mesoscopic device of the two monolayer graphene nanoribbons vertically stacked together,where the intersection forms a bilayer graphene lattice with a controllable twist angle.Using a tight-binding lattice model,we show that the longitudinal and transverse conductances exhibit significant valley polarization in the low energy regime for small twist angles.As the twist angle increases,the valley polarization shifts to the high energy regime.This arises from the regrouping effect of the electron band in the twisted bilayer graphene region.But for relatively large twist angles,no significant valley polarization is observed.These results are consistent with the spectral densities of the twisted bilayer graphene.
基金项目
National Natural Science Foundation of China(12174051)
National Natural Science Foundation of China(11874221)
维普
万方数据