▎ 摘　　要

Graphene provides excellent prospects of the dynamic tunability, low propagation loss, and extreme mode confinement for plasmonic excitations in the infra-red and terahertz frequencies. We show that in a deep subwavelength double graphene layer structure, graphene plasmons can be routed between two different graphene waveguides by relatively small chemical potential tuning. We develop a coupled mode theory that completely accounts for the switching behavior observed in numerical simulations. Such a deep subwavelength 1 x 2 device is a crucial enabling component towards large-scale integrated deep-subwavelength electromagnetic circuits. (C) 2013 AIP Publishing LLC.