  The surface plasmon-polaritons (SPPs) switch is the key element of the
integrated devices in optical computation and terahertz (THz) communications.
In this paper, we propose a novel design of THz SPPs switch based on quantum
engineering. Due to the robustness of coherent quantum control technique, our
switch is very robust against with perturbations of geometrical parameters and
presents a good performance at on-state (and off-state) from 0.5 THz to 0.7
THz. The on-state and off-state of our device can be controlled by the external
voltage. We believe this finding will be the great improvement for the
integrated optical computing and THz communications.
