Patent ID: 9741796
Date: 2017-08-22
CPC Classifications: H01L,H03H

Claim:
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 applied 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 applied 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 when a small bias is applied, electrons are driven to pass through the channel to become valley polarized in the bilayer graphene.