QUANTUM CELLULAR-AUTOMATON DEVICE USING THE IMAGE CHARGE EFFECT

A quantum cellular automaton (QCA) device that uses the image charge e ffect is proposed. This image-charge QCA device is constructed from ma ny unit cells on a metal substrate covered with an insulator layer. Ea ch unit cell consists of four quantum dots and two excess electrons. T wo positive image charges in the metal substrate maintain the charge n eutrality of each cell. The distance between two neighboring cells is designed to allow intercellular electron tunneling. The image-charge Q CA cell can overcome two basic problems: establishing charge neutralit y in each cell and loading electrons easily and precisely. We designed signal-transmission and elemental logic gate circuits using these ima ge-charge QCA cells, and simulated operation of the circuits by comput er simulation. It is demonstrated that the image-charge QCA circuits c an perform signal transmission and elemental logic operations and that electrons (two per cell) can be easily loaded into the image-charge Q CA circuits.