  Stubbed waveguides and stub transistors are candidates for next generation
electronic devices. In particular, such structures may be used in
spintronics-based quantum computation, because of its ability to induce
spin-polarized carriers. In this paper, we present the simulation of the
conductance of the stub transistor (single and double-gated), modeled with a
nearest-neighbor tight-binding Hamiltonian. The oscillatory behavior of the
channel conductance with the applied stub voltage is observed.
