Parameter regime of a resonance quantum switch

The design of a three-terminal resonance quantum switch is suggested in the form of a network consisting of a circular quantum well with four semi-infinite single-mode quantum wires attached to it. In the resonance case, when the Fermi level in the wires is close to an energy level in the well, the magnitude of the governing electric field on the well may be specified such that the switching effect is obtained; the quantum current across the switch from the incoming wire to the outgoing wires (terminals) is controlled via rotation of the orthogonal projection of the field onto the plane of the device. Using an approximate formula for the scattering matrix we define essential details of the design and the parameter regime of the switch depending on the desired working temperature, the Fermi level in the wires, and the effective mass of an electron.

Figure 1

Resonance quantum switch. The circular quantum well ${\Omega }_0$ with wires ${\Omega }_j$, $j=1,2,3,4$ attached. The wires are enumerated in a counterclockwise direction, beginning from the horizontal wire ${\Omega }_1$ on the left of the well. The modified well ${\stackrel{\mathrm{̃}}{\Omega }}_0$ is obtained as the complement of the wires in the circular well $\Omega$.