Transverse Magnetic Surface Plasmons in Graphene Nanoribbon Qubits: The Influence of a VO2 Substrate

We study the influence of the phase-change material VO2 on transverse magnetic (TM) surface plasmon (SP) modes in metallic arm-chair graphene nanoribbon (AGNR) qubits in the Lindhard approximation. We assess the effects of temperature as a dynamic knob for the transition from the insulating to the metallic phase on the TM SP modes in single-band (SB) and two-band (TB) transitions. We show that a VO2 substrate leads to TM SP modes in both SB and TB transitions. In addition, we observe that the SP modes have a lower frequency than those for a substrate of constant permittivity. In addition, we study the influence of the substrate-induced band gap delta ' on SP modes in TB transitions for the insulating and metallic phases of VO2.