Pure valley current generation in graphene nanostructure

We proposed a new method to generate pure valley current in a three-terminal graphene junction using intrinsic asymmetry in graphene nanostructures. The three-terminal junction consists of one zigzag lead and two armchair leads. We found that a pure valley current can be obtained in the zigzag lead by applying a positive bias to one of the armchair leads and a negative bias to the other armchair lead. Our theoretical results provide us with deeper understanding of the generation mechanism of pure valley current and may stimulate further experimental studies of pure valley current in graphene and graphene-like materials.