1 Bita Quantum AI Inc., 2021 Av. Atwater, Montréal, QC H3H 2P2, Canada.
2 Department of Physics, Concordia University, 7141 Sherbrooke Ouest, Montréal, QC H4B 1R6, Canada.

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 ?' on SP modes in TB transitions for the insulating and metallic phases of VO₂.