GRAPHENE-BASED VALLEY FILTER AND METHOD FOR OPERATING THE SAME

摘要

A graphene-based valley filter includes a bottom gate, a bilayer graphene and two top gates. The bilayer graphene is deposited on the bottom gate and includes scattering defects. The top gates are deposited on the bilayer graphene. The top gates define a channel in the bilayer graphene, and the scattering defects are located in the vicinity of the channel. A vertical electric field is formed to open a band gap and produce electronic energy subbands in the channel. A transverse in-plane electric field is formed to produce pseudospin splitting in the subbands of the bilayer graphene. The scattering defects are for producing scattering between two opposite energy valley states of the bilayer graphene, couples subband states of opposite pseudospins and opens a pseudogap at a crossing point of the two subbands. Electrons are passed through the channel to become valley polarized in the bilayer graphene.)

主权项

1. A graphene-based valley filter, comprising:
a bottom gate; a bilayer graphene deposited on the bottom gate, wherein the bilayer graphene comprises scattering defects; and two top gates deposited on the bilayer graphene, wherein the two top gates define a channel in the bilayer graphene, and the scattering defects are located in the vicinity of the channel; wherein a vertical electric field is formed between the bottom gate and the top gates to open a band gap as well as produce electronic energy subbands in the bilayer graphene channel, a transverse in-plane electric field is formed between the top gates to produce pseudospin splitting in the subbands of the bilayer graphene channel, the scattering defects are configured to produce a scattering between two energy valley states with opposite pseudospins in the bilayer graphene, couple subband states of opposite pseudospins and opens a pseudogap at a crossing point of the two subbands, and electrons are passed through the channel to become valley polarized in the bilayer graphene.